tag:blogger.com,1999:blog-71915412009-02-20T23:57:14.881-08:00LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.comBlogger55125tag:blogger.com,1999:blog-7191541.post-1102025959432943342004-12-02T14:19:00.000-08:002004-12-02T14:19:19.433-08:00Chapter 29, part 2 <br />Development and Inheritance <br />SECTION 29-5 The Second and Third Trimesters <br />Second and Third Trimesters <br />Second trimester <br />Organ systems increase in complexity <br />Third trimester <br />Many organ systems become fully functional <br />Fetus undergoes largest weight change <br />At end of gestation fetus and uterus push maternal organs out of position <br />Figure 29.9 The Second and Third Trimesters <br />Figure 29.10 Growth of the Uterus and Fetus <br />Figure 29.10 Growth of the Uterus and Fetus <br />Developing fetus totally dependent on maternal organs <br />Maternal adaptations include increased <br />Respiratory rate <br />Tidal volume <br />Blood volume <br />Nutrient and vitamin uptake <br />Glomerular filtration rate <br />Structural and Functional Changes in the Uterus <br />Progesterone inhibits uterine muscle contraction <br />Opposed by estrogens, oxytocin and prostaglandins <br />Multiple factors interact to produce labor contractions in uterine wall <br />Figure 29.11 Factors Involved in the Initiation of Labor and Delivery <br />SECTION 29-6 Labor and Delivery <br />Goal of labor is parturition <br />Stages of labor <br />Dilation <br />The cervix dilates and fetus moves toward cervical canal <br />Expulsion <br />The cervix completes dilation and fetus emerges <br />Placental <br />Ejection of the placenta <br />Figure 29.12 The Stages of Labor <br />Other labor and delivery situations <br />Premature labor <br />True labor begins before fetus has completed normal development <br />Difficult deliveries <br />When the fetus faces the pubis rather than the sacrum <br />The legs or buttocks enter the vaginal canal first (breech births) <br />Multiple births <br />Twins, triplets, etc. <br />Dizygotic or monozygotic situations <br />SECTION 29-7 Postnatal Development <br />Postnatal life stages <br />Neonatal period <br />Infancy <br />Childhood <br />Adolescence <br />Maturity <br />Senescence begins at maturity and ends in death <br />The neonatal period <br />From birth to one month <br />Respiratory, circulatory, digestive and urinary systems adjust <br />Infant must thermoregulate <br />Maternal mammary glands secrete colostrum first few days <br />Milk production thereafter <br />Both secretions are released via the milk let-down reflex <br />Body proportions change during infancy and childhood <br />Figure 29.13 The Milk Let-Down Reflex <br />Figure 29.14 Growth and Changes in Body Form <br />Adolescence <br />Begins at puberty <br />The period of sexual maturation <br />Ends when growth is completed <br />Puberty marked by <br />Increased production of GnRH <br />Rapid increase in circulating FSH and LH <br />Ovaries and testes become sensitive to FSH / LH <br />Gamete production initiated <br />Sex hormones produced <br />Growth rate increases <br />Hormonal changes at puberty produce gender specific differences in system <br />Differences are retained throughout life <br />Adolescence continues until growth completed <br />Further changes occur when sex hormones decline <br />Menopause <br />Male climacteric <br />Senescence <br />Aging affects functional capabilities of all system <br />SECTION 29-8 Genetics, Development, and Inheritance <br />Genes and chromosomes <br />Every somatic cell carries copies of the 46 original chromosomes in the zygote <br />Genotype – Chromosomes and their component genes <br />Phenotype – physical expression of the genotype <br />Patterns of inheritance <br />Somatic cells contain 23 pairs of chromosomes <br />Homologous chromosomes <br />22 pair of autosomes and one pair of sex chromosomes <br />Chromosomes contain DNA <br />Genes are functional segments of DNA <br />Figure 29.15 Human Chromosomes <br />Various forms of a gene are called alleles <br />Homozygous if homologous chromosomes carry the same alleles <br />Heterozygous if homologous chromosomes carry different alleles <br />Alleles are either dominant or recessive depending on expression <br />Punnett square diagram predicts characteristics of offspring <br />Figure 29.16 Predicting Phenotypic Characteristics by Using Punnett Squares <br />Inheritance <br />Simple inheritance <br />Phenotypic characteristics are determined by interactions between single pair of alleles <br />Polygenic inheritance <br />Phenotypic characteristics are determined by interactions among alleles on several genes <br />Sources of individual variation <br />Genetic recombination <br />Gene reshuffling <br />Crossing over and translocation <br />Occurs during meiosis <br />Spontaneous mutations <br />Random errors in DNA replication <br />Figure 29.17 Crossing over and Translocation <br />Sex-linked inheritance <br />Sex chromosomes are X chromosome and Y chromosome <br />Male = XY <br />Female = XX <br />X chromosome carries X-linked (sex linked) genes <br />Affect somatic structures <br />Have no corresponding alleles on Y chromosome <br />Figure 29.18 X-Linked inheritance <br />The Human Genome Project <br />Mapped more than 38,000 of our genes <br />Including some responsible for inherited disorders <br />Figure 29.19 A Map of the Human Chromosomes <br />You should now be familiar with: <br />The relationship between differentiation and development, and the various stages of development <br />The process of fertilization <br />The three prenatal periods and describe the major events associated with each <br />The importance of the placenta as an endocrine organ <br />You should now be familiar with: <br />The structural and functional changes in the uterus during gestation <br />The events that occur during labor and delivery <br />The basic principles of genetics as they relate to the inheritance of human traits <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110202595943294334?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com4tag:blogger.com,1999:blog-7191541.post-1102025765830814052004-12-02T14:15:00.000-08:002004-12-02T14:16:05.830-08:00Chapter 29, part 1 <br />Development and Inheritance <br />Learning Objectives <br />Explain the relationship between differentiation and development and specify the various stages of development <br />Describe the process of fertilization <br />List the three prenatal periods and describe the major events associated with each <br />Discuss the importance of the placenta as an endocrine organ <br />Learning Objectives <br />Discuss the structural and functional changes in the uterus during gestation <br />List and discuss the events that occur during labor and delivery <br />Relate basic principles of genetics to the inheritance of human traits <br />SECTION 29-1 An Overview of Topics in Development <br />Differentiation and development <br />Development <br />Gradual modification of physical and physiological characteristics <br />Differentiation <br />The creation of different types of cells <br />Stages of development <br />Prenatal development <br />Embryological <br />Changes occurring the first two months after fertilization <br />Fetal <br />Begins at the start of the ninth week and continues until birth <br />Postnatal development <br />Commences at birth and continues to maturity <br />SECTION 29-2 Fertilization <br />Fertilization (conception) <br />Occurs in the uterine tubes <br />Within a day of ovulation <br />Spermatozoa cannot fertilize an ovum until after capacitation <br />Figure 29.1 Fertilization <br />Figure 29.1 Fertilization <br />The Oocyte at Ovulation <br />Oocyte is in meiosis II <br />Surrounded by the corona radiate <br />Spermatozoa release hyaluronidase and acrosin <br />Enzymes required to penetrate corona radiate <br />Single spermatozoan contacts oocyte, fertilization begins <br />Oocyte activation <br />Oocyte activation <br />Oocyte completes meiosis II <br />Functionally mature ovum <br />Female pronucleus and male pronucleus fuse (amphimixis) <br />Polyspermy prevented by membrane depolarization and cortical reaction <br />SECTION 29-3 The Stages of Prenatal Development <br />Embryonic and Fetal Periods <br />Induction <br />During prenatal development differences in cytoplasmic composition trigger changes in genetic activity <br />Gestation periods <br />Three trimesters <br />SECTION 29-4 The First Trimester <br />The First Trimester <br />Cleavage <br />Zygote becomes a preembryo then a blastocyst <br />Implantation <br />Blastocyst burrows into uterine endometrium <br />Placentation <br />Blood vessels form around blastocyst and placenta develops <br />Embryogenesis <br />Formation of a viable embryo <br />Cleavage and blastocyst formation <br />A series of cell divisions that subdivides the cytoplasm of the zygote <br />Trophoblast – outer layer of cells <br />Inner cell mass – cluster of cells at one end of blastocyst <br />Figure 29.2 Cleavage and Blastocyst Formation <br />Implantation <br />Occurs about 7 days after fertilization <br />Trophoblast enlarges and spreads <br />Maternal blood flows through open lacunae <br />Gastrulation <br />Embryonic disc composed of germ layers <br />Endoderm <br />Mesoderm <br />Ectoderm <br />Figure 29.3 Stages in Implantation <br />Figure 29.4 The Inner Cell Mass and Gastrulation <br />Germ layers <br />Gastrulation <br />By day 12 surface cells move toward the primitive streak <br />A third germ layer forms <br />The three germ layers are: <br />Ectoderm – superficial cells that did not migrate <br />Endoderm – cells facing the blastocoele <br />Mesoderm – migrating cells between ectoderm and endoderm <br />Extraembryonic Membranes <br />Four extraembryonic membranes: <br />Yolk sac <br />Amnion <br />Allantois <br />Chorion <br />Figure 29.5 Extraembryonic Membranes and Placenta Formation <br />Figure 29.5 Extraembryonic Membranes and Placenta Formation <br />Figure 29.5 Extraembryonic Membranes and Placenta Formation <br />Embryo Anatomy <br />Yolk sac <br />Important site of blood cell formation <br />Amnion <br />Encloses fluid that surrounds and cushions developing embryo <br />Allantois <br />Eventually becomes bladder <br />Chorion <br />Figure 29.6 A Three-Dimensional View of Placental Structure <br />Placentation <br />Chorionic villi extend into maternal tissue <br />Forms intricate branching network for maternal blood <br />Umbilical cord connects fetus to placenta <br />Hormones of the placenta <br />Trophoblast secretes hormones to maintain pregnancy <br />HCG <br />Estrogens <br />Progesterone <br />hPL <br />Placental prolactin <br />relaxin <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110202576583081405?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1101249572089634352004-11-23T14:35:00.000-08:002004-11-23T14:39:32.090-08:00Are you aware that there is really only one meeting session to go over all thwe material? <br />I do not believe that we can do that. Especially with the genetic cross problems and developmental models. Really need to have the lab final on the day of the lecture fianl. It really will not make a difference. Material is the same, it would still be like studying once. You just have an extra week to accomplish the task! <br /> <br /> <br />sincerely, <br /> <br />Mr. Lechko <br /> <br /> <br />send e-mail; <a href="mailto:canucmelml@hotmail.com">canucmelml@hotmail.com</a> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110124957208963435?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100817259977837272004-11-18T14:33:00.000-08:002004-11-18T14:34:19.976-08:00Chapter 28, part 4 <br />The Reproductive System <br />Uterine cycle <br />Repeating series of changes in the endometrium <br />Continues from menarche to menopause <br />Menses <br />Degeneration of the endometrium <br />Menstruation <br />Proliferative phase <br />Restoration of the endometrium <br />Secretory phase <br />Endometrial glands enlarge and accelerate their rates of secretion <br />Figure 28.20 The Uterine Cycle <br />The vagina <br />Major functions <br />Passageway for elimination of menstrual fluids <br />Receives the penis during sexual intercourse <br />Forms the inferior portion of the birth canal <br />Figure 28.21 The Histology of the Vagina <br />External genitalia <br />Vulva <br />Vestibule <br />Labia minora and majora <br />Paraurethral glands <br />Clitoris <br />Lesser and greater vestibular glands <br />Figure 28.22 The Female External Genitalia <br />Mammary glands <br />Pectoral fat pad <br />Nipple surrounded by the areola <br />Function in lactation under control of reproductive hormones <br />Figure 28.23 The Mammary Glands <br />Hormones of the female reproductive cycle <br />Control the reproductive cycle <br />Coordinate the ovarian and uterine cycles <br />Hormones of the female reproductive cycle <br />Key hormones include: <br />FSH <br />Stimulates follicular development <br />LH <br />Maintains structure and secretory function of corpus luteum <br />Estrogens <br />Have multiple functions <br />Progesterones <br />Stimulate endometrial growth and secretion <br />Figure 28.25 The Hormonal Regulation of Ovarian Activity <br />Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle <br />Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle <br />SECTION 28-4 The Physiology of Sexual Intercourse <br />Male sexual function <br />Arousal <br />Leads to erection of the penis <br />Parasympathetic outflow over the pelvic nerves <br />Emission and ejaculation <br />Occur under sympathetic stimulation <br />Results in semen being pushed toward external urethral opening <br />Detumescence <br />Subsidence of erection <br />Mediated by the sympathetic nervous system <br />Female sexual function <br />Stages are comparable to those of male sexual function <br />Arousal causes clitoral erection <br />Vaginal surfaces are moistened <br />Parasympathetic stimulation causes engorgement of blood vessels in the nipples <br />SECTION 28-5 Aging and the Reproductive System <br />Menopause <br />The time that ovulation and menstruation cease <br />Typically around age 45-55 <br />Accompanied by a decline in circulating estrogen and progesterone <br />Rise in GnRH, FSH, LH <br />Male climacteric <br />Levels of circulating testosterone begin to decline <br />FSH and LH levels rise <br />Gradual reduction in sexual activity <br />You should now be familiar with: <br />The components of the reproductive system, and their functions <br />The components of the male and female reproductive systems <br />The processes of meiosis and gametogenesis in both sexes <br />You should now be familiar with: <br />The roles played by the male reproductive tract and accessory glands in the functional maturation, nourishment, storage, and transport of spermatozoa <br />The anatomical, physiological, and hormonal aspects of the male and female reproductive cycles <br />The physiology of sexual intercourse <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081725997783727?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100817134465432932004-11-18T14:31:00.000-08:002004-11-18T14:32:14.466-08:00Chapter 28, part 3 <br />The Reproductive System <br />SECTION 28-3 The Reproductive System of the Female <br />Principle organs of the female reproductive system <br />Ovaries <br />Uterine tubes <br />Uterus <br />Vagina <br />Support and stabilization <br />Ovaries, uterine tubes and uterus enclosed within broad ligament <br />Mesovarium supports and stabilizes ovary <br />Figure 28.13 The Female Reproductive System <br />The ovaries <br />Held in position by ovarian and suspensory ligaments <br />Blood vessels enter at ovarian hilus <br />Tunica albuginea covers ovary <br />Figure 28.14 The Ovaries and Their Relationships to the Uterine Tube and Uterus <br />Oogenesis <br />Ovum production <br />Occurs monthly in ovarian follicles <br />Part of ovarian cycle <br />Follicular phase (preovulatory) <br />Luteal phase (postovulatory) <br />Figure 28.15 Oogenesis <br />The ovarian cycle <br />Steps in the ovarian cycle <br />Formation of primary, secondary, and tertiary follicles <br />Ovulation <br />Formation and degeneration of the corpus luteum <br />Degradation of the corpus luteum <br />Figure 28.16 The Ovarian Cycle <br />Figure 28.16 The Ovarian Cycle <br />The Uterine tubes <br />Uterine tubes (Fallopian tubes or oviducts) <br />Infundibulum <br />End closest to the ovary with numerous fimbriae <br />Ampulla <br />The middle portion <br />Isthmus <br />A short segment connected to the uterine wall <br />Each uterine tube opens directly into uterine cavity <br />Fertilization occurs in uterine tube <br />12-24 hours after ovulation <br />During passage from infundibulum to uterus <br />Figure 28.17 The Uterine Tubes <br />The uterus <br />Muscular organ <br />Mechanical protection <br />Nutritional support <br />Waste removal for the developing embryo and fetus <br />Supported by the broad ligament and 3 pairs of suspensory ligaments <br />Uterus <br />Major anatomical landmarks <br />Body <br />Isthmus <br />Cervix <br />Cervical os (internal orifice) <br />Uterine cavity <br />Cervical canal <br />Internal os (internal orifice) <br />Uterine wall consists of three layers: <br />Myometrium – outer muscular layer <br />Endometrium – a thin, inner, glandular mucosa <br />Perimetrium – an incomplete serosa continuous with the peritoneum <br />Figure 28.18 The Uterus <br />Figure 28.18 The Uterus <br />Figure 28.19 The Uterine Wall <br />Figure 28.19 The Uterine Wall <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081713446543293?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100817029568694182004-11-18T14:30:00.000-08:002004-11-18T14:30:29.570-08:00Chapter 28, part 2 <br />The Reproductive System <br />Spermatogenesis <br />Seminiferous tubules <br />Contain spermatogonia <br />Stem cells involved in spermatogenesis <br />Contain sustentacular cells <br />Sustain and promote development of sperm <br />Figure 28.5 The Seminiferous Tubules <br />Figure 28.5 The Seminiferous Tubules <br />Figure 28.6 Chromosomes in Mitosis and Meiosis <br />Spermatogenesis <br />Spermatogenesis involves three processes <br />Mitosis <br />Meiosis <br />Spermiogenesis <br />Figure 28.7 Spermatogenesis <br />Anatomy of spermatozoon <br />Each spermatozoon has: <br />Head <br />Nucleus and densely packed chromosomes <br />Middle piece <br />Mitochondria that produce the ATP needed to move the tail <br />Tail <br />The only flagellum in the human body <br />Figure 28.8 Spermiogenesis and Spermatozoon Structure <br />Male reproductive tract <br />Testes produce mature spermatozoa <br />Sperm enter epididymus <br />Elongated tubule with head, body and tail regions <br />Monitors and adjusts fluid in seminiferous tubules <br />Stores and protects spermatozoa <br />Facilitates functional maturation of spermatozoa <br />Figure 28.9 The Epididymus <br />Ductus deferens AKA vas deferens <br />Begins at epididymus <br />Passes through inguinal canal <br />Enlarges to form ampulla <br />Ejaculatory duct at base of seminal vesicle and ampulla <br />Empties into urethra <br />Urethra <br />Urinary bladder to tip of penis <br />Three regions <br />Prostatic <br />Membranous <br />Penile <br />Accessory glands <br />Seminal vesicles <br />Active secretory gland <br />Contributes ~60% total volume of semen <br />Secretions contain fructose, prostaglandins, fibrinogen <br />Accessory glands <br />Prostate gland <br />Secretes slightly acidic prostate fluid <br />Bulbourethral glands <br />Secrete alkaline mucus with lubricating properties <br />Figure 28.10 The Ductus Deferens and Accessory Glands <br />Contents of Semen <br />Typical ejaculate = 2-5 ml fluid <br />Contains between 20 – 100 million spermatozoa per ml <br />Seminal fluid <br />A distinct ionic and nutritive glandular secretion <br />External genitalia <br />Male external genitalia consist of the scrotum and the penis <br />Skin overlying penis resembles scrotum <br />Penis <br />Contains three masses of erectile tissue <br />2 corpora cavernosa beneath fascia <br />1 corpus spongiosum surrounding urethra <br />Dilation of erectile tissue produces erection <br />Figure 28.11 The Penis <br />Hormones and male reproductive function <br />FSH (Follicle stimulating hormone) <br />Targets sustentacular cells to promote spermatogenesis <br />LH (leutinizing hormone) <br />Causes secretion of testosterone and other androgens <br />GnRH (Gonadotropin releasing hormone) <br />Testosterone <br />Most important androgen <br />Figure 28.12 Hormonal Feedback and the Regulation of the Male Reproductive Function <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081702956869418?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100816861561035372004-11-18T14:27:00.000-08:002004-11-18T14:27:41.560-08:00Chapter 28, part 1 <br />The Reproductive System <br />SECTION 28-1 The Reproductive System <br />Learning Objectives <br />Specify the components of the reproductive system, and summarize their functions <br />Describe the components of the male and female reproductive systems <br />Outline the processes of meiosis and gametogenesis in both sexes <br />Explain the roles played by the male reproductive tract and accessory glands in the functional maturation, nourishment, storage, and transport of spermatozoa <br />Learning Objectives <br />Summarize the anatomical, physiological, and hormonal aspects of the male and female reproductive cycles <br />Discuss the physiology of sexual intercourse <br />Reproductive System <br />Reproductive system functions in gamete <br />Production <br />Storage <br />Nourishment <br />Transport <br />Fertilization <br />Fusion of male and female gametes to form a zygote <br />SECTION 28-1 Introduction to the Reproductive System <br />Reproductive system includes: <br />Gonads (testes, ovaries) <br />Ducts <br />Accessory glands and organs <br />External genitalia <br />Males and Females <br />Males <br />Testes produce spermatozoa <br />Expelled from body in semen during ejaculation <br />Females <br />Ovaries produce oocytes <br />Immature ovum <br />Travels along uterine tube toward uterus <br />Vagina connects uterus with exterior of body <br />SECTION 28-2 The Reproductive System of the Male <br />Male Reproductive System <br />Pathway of spermatozoa <br />Epididymis <br />Ductus deferens <br />Ejaculatory duct <br />Accessory organs <br />Seminal vesicles <br />Prostate gland <br />Bulbourethral glands <br />Scrotal sac encloses testes <br />Penis <br />Figure 28.1 The Male Reproductive System <br />The testes <br />Descent of the testes <br />Movement of testes through inguinal canal into scrotum <br />Occurs during fetal development <br />Testes remain connected to internal structures <br />Spermatic cords <br />Figure 28.2 The Descent of the Testes <br />Figure 28.2 The Descent of the Testes <br />Figure 28.3 The Male Reproductive System in Anterior View <br />Male Anatomy <br />Musculature of scrotal sac <br />Dartos muscle wrinkles scrotal sac <br />Cremaster muscle pulls sac close to body <br />Testes anatomy <br />Tunica albuginea surrounds testis <br />Septa extend from tunica albuginea to epididymus <br />Lobules <br />Sperm production <br />In seminiferous tubules <br />Interstitial cells between seminiferous tubules <br />Secrete sex hormones <br />Sperm pass through rete testis <br />Efferent ductules connect rete testis to epididymus <br />Figure 28.4 The Structure of the Testes <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081686156103537?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692663923988322004-11-05T14:10:00.000-08:002004-11-05T14:11:03.923-08:00SECTION 22-6 B Cells and Antibody-mediated Immunity <br />B cell sensitization of activation <br />Sensitization – the binding of antigens to the B cell membrane antibodies <br />Antigens then displayed on B cell Class II MHC <br />TH cells activated by same antigen stimulate B cell <br />Active B cell differentiates into Memory B Cell or Plasma cell <br />Plasma cells synthesize and release antibody <br />Figure 22.20 The Sensitization and Activation of B Cells <br />Antibodies structure <br />Antibodies are Y-shaped proteins consisting of: <br />Two parallel polypeptide chains <br />Heavy chains and light chains <br />Constant region and variable region <br />Antigen binding site <br />Figure 22.21 Antibody Structure <br />Figure 22.21 Antibody Structure <br />Figure 22.21 Antibody Structure <br />Actions of antibodies include: <br />Neutralization <br />Agglutination and precipitation <br />Activation of complement <br />Attraction of phagocytes <br />Opsinization <br />Stimulation of inflammation <br />Prevention of adhesion <br />Classes of Antibodies (immunoglobins) <br />IgG – resistance against many viruses, bacteria and bacterial toxins <br />IgE – accelerates local inflammation <br />IgD – found on the surface of B cells <br />IgM – first type secreted after antigen arrives <br />IgA – primarily found in glandular sec <br />Primary and secondary antibody response <br />Primary response <br />Takes about two weeks to develop <br />The Lymphatic System and Immunity <br />Produced by plasma cells <br />Secondary response <br />Rapid increase in IgG <br />Maximum antibody titer app <br />Figure 22.22 The Primary and Secondary Immune Responses <br />Figure 22.23 An Integrated Summary of the Immune Response <br />Figure 22.25 The Course of the Body’s Response to Bacterial Infection <br />Focus on Hormones of the Immune System <br />Interleukins <br />Increase T cell sensitivity <br />Stimulate B cell activity, plasma formation, and antibody production <br />Enhance nonspecific defenses <br />Moderate the immune system <br />Interferons <br />Tumor Necrosis Factors (TNFs) slow tumor growth <br />Colony Stimulating Factors (CSFs) <br />SECTION 22-7 Normal and Abnormal Resistance <br />Development of the Immune Response <br />Immunological competence <br />The ability to demonstrate an immune response after exposure to an antigen <br />Fetuses receive immunity from the maternal bloodstream <br />Infants acquire immunity following exposure <br />Immune disorders <br />Autoimmune disorders <br />Immune response mistakenly targets normal cells <br />Immunodeficiency diseases <br />Immune system does not develop properly or is blocked <br />Allergies <br />Inappropriate or excessive immune response to allergens <br />Immediate hypersensitivity (type I) <br />Cytotoxic reactions (type II) <br />Immune complex disorders (type III) <br />Delayed hypersensitivity (type IV) <br />Anaphylaxis <br />Circulating allergen affects mast cells throughout body <br />Figure 22.26 The Mechanism of Anaphylaxis <br />Stress and the immune response <br />Interleukin-1 released by active macrophages <br />Triggers release of ACTH resulting in glucocorticoid release <br />Moderates the immune response <br />Lowers resistance to disease <br />Stress can cause the following: <br />Depression of the inflammatory response <br />Phagocytic reduction <br />Inhibition of interleukin secretion <br />SECTION 22-8 Aging and the Immune Response <br />With age <br />Immune system becomes less effective <br />Increased susceptibility to infection <br />Immune surveillance declines <br />You should now be familiar with: <br />The structure and function of lymphatic cells, tissues and organs <br />The body’s nonspecific defenses and the components and mechanisms of each <br />Specific resistance, cell-mediated immunity and antibody mediated immunity <br />The role of the T cell, B cell and antibodies in specific immunity <br />The origin, development, activation and regulation of normal resistance to disease <br />The effects of stress and aging on the immune system <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969266392398832?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692589531511942004-11-05T14:09:00.000-08:002004-11-05T14:09:49.533-08:00Chapter 22, part 3 <br />The Lymphatic System and Immunity <br />SECTION 22-4 Specific Defenses <br />Forms of immunity <br />Innate immunity <br />Genetically determined <br />Present at birth <br />Acquired immunity <br />Not present at birth <br />Achieved by exposure to antigen <br />Active immunity <br />Passive immunity <br />Figure 22.14 Types of Immunity <br />Properties of immunity <br />Specificity – activated by and responds to a specific antigen <br />Versatility – is ready to confront any antigen at any time <br />Memory – "remembers" any antigen it has encountered <br />Tolerance – responds to foreign substances but ignores normal tissues <br />The immune system response <br />Antigen triggers an immune response <br />Activates T cells and B cells <br />T cells are activated after phagocytes exposed to antigen <br />T cells attack the antigen and stimulate B cells <br />Activated B cells mature and produce antibody <br />Antibody attacks antigen <br />Figure 22.15 An Overview of the Immune Response <br />SECTION 22-5 T cells and Cell-mediated Immunity <br />Major types of T cells <br />Cytotoxic T cells (TC) – attack foreign cells <br />Helper T cells (TH) – activate other T cells and B cells <br />Suppressor T cells (TS) – inhibit the activation of T and B cells <br />Antigen presentation <br />Antigen-glycoprotein combination appears on a cell membrane <br />Called MHC proteins (Major Histocompatibility Complex) <br />Coded for by genes of the MHC <br />T-cells sensitive to the antigen are activated upon contact <br />MHC classes <br />Class I – found on all nucleated cells <br />Class II – found on antigen presenting cells and lymphocytes <br />Lymphocytes respond to antigens bound to either class I or class II MHC proteins <br />Antigen recognition <br />T cell membranes contain CD markers <br />CD3 markers present on all T cells <br />CD8 markers on cytotoxic and suppressor T cells <br />CD4 markers on helper T cells <br />Figure 22.16 Antigens and MHC Proteins <br />Figure 22.16 Antigens and MHC Proteins <br />Figure 22.16 Antigens and MHC Proteins <br />Activation of CD8 cells <br />Responds quickly giving rise to other T cells <br />Cytotoxic T cells – seek out and destroy abnormal cells <br />lymphotoxin <br />Memory TC cells – function during a second exposure to antigen <br />Suppressor T cells – suppress the immune response <br />Figure 22.17 Antigen Recognition and the Activation of Cytotoxic T Cells <br />Figure 22.17 Antigen Recognition and the Activation of Cytotoxic T Cells <br />Activation of CD4 T cells by antigens presented on class II MHC proteins <br />Produces helper T cells and memory T cells <br />Activated helper T cells <br />Secrete lymphokines that coordinate specific and nonspecific defenses <br />Enhance nonspecific defenses <br />Stimulate the activity of NK cells <br />Promote activation of B cells <br />Figure 22.18 Antigen Recognition and Activation of Helper T cells <br />Figure 22.19 A Summary of the Pathways of T Cell Activation <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969258953151194?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692521938253732004-11-05T14:08:00.000-08:002004-11-05T14:08:41.936-08:00Chapter 22, part 2 <br />The Lymphatic System and Immunity <br />The Thymus <br />Located behind sternum in anterior mediastinum <br />Capsule <br />Two lobes <br />Divided into lobules, each with a cortex and medulla <br />Cortical lymphocytes surrounded by reticular endothelial cells <br />Maintain blood–thymus barrier <br />Secretes thymic hormones: thymosins, thymopoietins, and thymulin <br />Figure 22.8 The Thymus <br />The Spleen <br />Largest mass of lymphoid tissue <br />Cellular components form pulp <br />Red pulp contains RBC <br />White pulp similar to lymphoid nodules <br />Spleen functions include <br />Removal of abnormal blood cells and other blood components <br />Storage of iron <br />Initiation of the specific immune response <br />Figure 22.9 The Spleen <br />Lymphatic system and body defenses <br />Nonspecific defenses <br />Do not distinguish one type of threat from another <br />7 types <br />Specific defenses <br />Protect against particular threats <br />Depend upon the activation of lymphocytes <br />SECTION 22-3 Nonspecific Defenses <br />Nonspecific Defenses, Physical barriers <br />Keep hazardous organisms outside the body <br />Includes hair, epithelia, secretions of integumentary and digestive systems <br />Figure 22.10 Nonspecific Defenses (Part 1 - Physical Barriers) <br />Nonspecific Defenses, Phagocytes <br />Remove cellular debris and respond to invasion by foreign pathogens <br />Monocyte-macrophage system - Fixed and free <br />Microphages – Neutrophils and eosinophils <br />Move by diapedesis <br />Exhibit chemotaxis <br />Figure 22.10 Nonspecific Defenses(Part 2 - Phagocytes) <br />Nonspecific Defenses, Immunological surveillance <br />Constant monitoring of normal tissue by NK cells <br />NK cells <br />Recognize cell surface markers on foreign cells <br />Destroy cells with foreign antigens <br />NK cell activation <br />Recognition of unusual surface proteins <br />Rotation of the Golgi toward the target cell and production of perforins <br />Release of perforins by exocytosis <br />Interaction of perforins causing cell lysis <br />Figure 22.10 Nonspecific Defenses(Part 3 - Immunological Surveillance) <br />Figure 22.11 How Natural Killer Cells Kill Cellular Targets <br />Nonspecific Defenses, Interferons (cytokines) <br />Small proteins released by virally infected cells <br />Trigger the production of antiviral proteins <br />Three major types of interferons are: <br />Alpha– produced by leukocytes and attract/stimulate NK cells <br />Beta– secreted by fibroblasts causing slow inflammation <br />Gamma – secreted by T cells and NK cells stimulate macrophage activity <br />Figure 22.10 Nonspecific Defenses(Part 4 - Interferons) <br />Nonspecific Defenses, Complement system <br />Cascade of ~11 plasma complement proteins (C) <br />Destroy target cell membranes <br />Stimulate inflammation <br />Attract phagocytes <br />Enhance phagocytosis <br />Complement proteins interact with on another via two pathways <br />Classical <br />Alternative <br />Figure 22.10 Nonspecific Defenses(Part 5 - Complement System) <br />Figure 22.12 Complement Activation <br />Nonspecific Defenses, Inflammation <br />Localized tissue response to injury producing <br />Swelling <br />Redness <br />Heat <br />Pain <br />Effects of inflammation include <br />Temporary repair of injury <br />Slowing the spread of pathogens <br />Mobilization of local, regional, and systemic defenses <br />Figure 22.10 Nonspecific Defenses(Part 6 - Inflammatory Response) <br />Figure 22.13 Inflammation <br />Nonspecific Defenses, Fever <br />Maintenance of a body temperature above 37.2oC (99oF) <br />Pyrogens reset the hypothalamic thermostat and raise body temperature <br />Pathogens, toxins, antigen-antibody complexes can act as pyrogens <br />Figure 22.10 Nonspecific Defenses(Part 7 - Fever) <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969252193825373?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692446514329452004-11-05T14:07:00.000-08:002004-11-05T14:07:26.513-08:00Learning Objectives <br />Describe the structure and function of lymphatic cells, tissues and organs <br />List the body’s nonspecific defenses and describe the components and mechanisms of each <br />Define specific resistance and distinguish between cell-mediated immunity and antibody mediated immunity <br />Learning Objectives <br />Discuss the role of the T cell, B cell and antibodies in specific immunity <br />Describe the origin, development, activation and regulation of normal resistance to disease <br />Discuss the effects of stress and aging on the immune system <br />SECTION 22-1 An Overview of the Lymphatic System and Immunity <br />lymphatic system <br />The lymphatic system <br />Contains cells, tissues, and organs responsible for defending the body <br />Lymphocytes resist infection and disease by responding to <br />Invading pathogens such as bacteria or viruses <br />Abnormal body cells such as cancer cells <br />Foreign proteins such as toxins <br />Figure 22.1 The Components of the Lymphatic System <br />SECTION 22-2 Organization of the Lymphatic System <br />The lymphatic system consists of <br />Lymph <br />Lymphatic vessels <br />Lymphoid tissues and organs <br />Lymphocytes and supporting phagocytic cells <br />Functions of lymphatic system <br />Primary function is production, maintenance, and distribution of lymphocytes <br />Lymphocytes must: <br />Detect where problems exist <br />Be able to reach the site of injury or infection <br />Lymphatic vessels include <br />Lymphatic capillaries <br />Small lymphatic vessels <br />Major lymph-collecting vessels <br />Figure 22.2 Lymphatic Capillaries <br />Figure 22.3 Lymphatic Vessels and Valves <br />Major lymph-collecting vessels <br />Superficial and deep lymphatics <br />Thoracic duct <br />Cisterna chyli <br />Right lymphatic duct <br />Figure 22.4 The Relationship between the Lymphatic Ducts and the Venous System <br />Figure 22.4 The Relationship between the Lymphatic Ducts and the Venous System <br />Figure 22.4 The Relationship between the Lymphatic Ducts and the Venous System <br />Lymphocytes <br />Three classes of lymphocytes <br />T (thymus dependent) cells <br />B (bone marrow-derived) cells <br />NK (natural killer) cells <br />Lymphocyte production (lymphopoiesis) <br />Involves bone marrow, thymus, and peripheral lymphoid tissue <br />B cells and NK cells mature in bone marrow <br />T cells mature in the thymus <br />Figure 22.5 The Derivation and Distribution of Lymphocytes <br />Lymphoid tissue <br />Connective tissue dominated by lymphocytes <br />Lymphoid nodules <br />Lymphocytes densely packed in areolar tissue <br />Found in the respiratory, digestive, and urinary tracts <br />MALT (mucosa-associated lymphoid tissue) <br />Collection of lymphoid tissues linked with the digestive system <br />Figure 22.6 Lymphoid Nodules <br />Lymphoid organs <br />Lymph nodes – function in the purification of lymph <br />Afferent lymphatics – carry lymph to nodes <br />Efferent lymphatics – carry lymph from nodes <br />Deep cortex dominated by T cells <br />Outer cortex and medulla contains B cells <br />Figure 22.7 The Structure of a Lymph Node <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969244651432945?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1098394031192085722004-10-21T14:26:00.000-07:002004-10-21T14:27:11.193-07:00Chapter 3, part 1 <br />An Introduction to The Cellular Level of Organization <br />Learning Objectives <br />List the main points of the cell theory. <br />Describe the chief structural features of the cell membrane. <br />Describe the organelles of a typical cell, and give their specific functions. <br />Summarize the process of protein synthesis. <br />Describe the various transport mechanisms used by cells, and relate this to the transmembrane potential. <br />Describe the cell life cycle, mitosis and cellular differentiation. <br />SECTION 3-1 An Introduction to Cells <br />The cell theory states: <br />Cells are the building blocks of all plants and animals <br />Cells are produced by the division of preexisting cells <br />Cells are the smallest units that perform all vital physiological functions <br />Each cell maintains homeostasis at the cellular level <br />Homeostasis at higher levels reflects combined, coordinated action of many cells <br />Figure 3.1 The Diversity of Cells in the Human Body <br />Cell biology <br />Cytology, the study of the structure and function of cells <br />The human body contains both somatic and sex cells <br />Figure 3.2 The Anatomy of a Representative Cell <br />A typical cell <br />Is surrounded by extracellular fluid, which is the interstitial fluid of the tissue <br />Has an outer boundary called the cell membrane or plasma membrane <br />SECTION 3-2 The Cell Membrane <br />Cell membrane functions include: <br />Physical isolation <br />Regulation of exchange with the environment <br />Structural support <br />Figure 3.3 The Cell Membrane <br />The cell membrane is a phospholipid bilayer with proteins, lipids and carbohydrates. <br />Membrane proteins include: <br />Integral proteins <br />Peripheral proteins <br />Anchoring proteins <br />Recognition proteins <br />Receptor proteins <br />Carrier proteins <br />Channels <br />Figure 3.4 Membrane proteins <br />Membrane carbohydrates form the glycocalyx <br />Proteoglycans <br />Glycolipids <br />Glycoproteins <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109839403119208572?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com1tag:blogger.com,1999:blog-7191541.post-1098393896810145392004-10-21T14:24:00.000-07:002004-10-21T14:24:56.810-07:00Chapter 18, part 3 <br />The Endocrine System <br />SECTION 18-6 The Adrenal Glands <br />Adrenal cortex <br />Manufactures steroid hormones (corticosteroids) <br />Cortex divided into three layers <br />Zona glomerulosa (produces mineralocorticoids) <br />Zona fasciculate (produces glucocorticoids) <br />Zona reticularis (produces androgens) <br />Figure 18.16 The Adrenal Gland <br />Figure 18.17 Adrenal Abnormalities <br />Adrenal medulla <br />Produces epinephrine (~75 - 80%) <br />Produces norepinephrine (~25-30%) <br />SECTION 18-7 The Pineal Gland <br />Pineal gland <br />Contains pinealocytes <br />Synthesize melatonin <br />Suggested functions include inhibiting reproductive function, protecting against damage by free radicals, setting circadian rhythms <br />SECTION 18-1 The Pancreas <br />The pancreatic islets <br />Clusters of endocrine cells within the pancreas called Islets of Langerhans or pancreatic islets <br />Alpha cells secrete glucagons <br />Beta cells secrete insulin <br />Delta cells secrete GH-IH <br />F cells secrete pancreatic polypeptide <br />Figure 18.18 The Endocrine Pancreas <br />Insulin and glucagon <br />Insulin lowers blood glucose by increasing the rate of glucose uptake and utilization <br />Glucagon raises blood glucose by increasing the rates of glycogen breakdown and glucose manufacture by the liver <br />Figure 18.19 The Regulation of Blood Glucose Concentrations <br />SECTION 18-9 The Endocrine Tissues of Other Systems <br />The intestines <br />Produce hormones important to the coordination of digestive activities <br />The kidneys <br />Produce calcitriol and erythropoietin (EPO) and the enzyme rennin <br />Calcitriol = stimulates calcium and phosphate ion absorption along the digestive tract <br />EPO stimulates red blood cell production by bone marrow <br />Renin converts angiotensinogen to angiotensin I <br />Angiotensin I converted to angiotensin II in the lungs <br />Stimulates adrenal production of aldosterone <br />Stimulates pituitary gland release of ADH <br />Promotes thirst <br />Elevates blood pressure <br />Figure 18.20 Endocrine Functions of the Kidneys <br />Figure 18.20 Endocrine Functions of the Kidneys <br />The heart <br />Specialized muscle cells produce natriuretic peptides when blood pressure becomes excessive <br />Generally oppose actions of angiotensin II <br />The thymus <br />Produces thymosins <br />Help develop and maintain normal immune defenses <br />The gonads <br />Interstitial cells of the testes produce testosterone <br />Most important sex hormone in males <br />In females, oocytes develop in follicles <br />Follicle cells produce estrogens <br />After ovulation, the follicle cells form a corpus luteum that releases a mixture of estrogens and progesterone <br />Adipose tissues secrete <br />Leptin, a feedback control for appetite <br />Resistin, which reduces insulin sensitivity <br />SECTION 18-10 Patterns of Hormonal Interaction <br />Hormones often interact, producing <br />Antagonistic (opposing) effects <br />Synergistic (additive) effects <br />Permissive effects (one hormone is required for the other to produce its effect) <br />Integrative effects (hormones produce different but complimentary results) <br />Hormones and growth <br />Normal growth requires the interaction of several endocrine organs <br />Six hormones are important <br />GH <br />Thyroid hormones <br />Insulin <br />PTH <br />Calcitriol <br />Reproductive hormones <br />Hormones and stress <br />Stress = any condition that threatens homeostasis <br />GAS (General Adaptation Syndrome) is our bodies response to stress-causing factors <br />Three phases to GAS <br />Alarm phase (immediate, fight or flight, directed by the sympathetic nervous system) <br />Resistance phase (dominated by glucocorticoids) <br />Exhaustion phase (breakdown of homeostatic regulation and failure of one or more organ systems) <br />Figure 18.21 The General Adaptation Syndrome <br />Figure 18.21 The General Adaptation Syndrome <br />Figure 18.21 The General Adaptation Syndrome <br />Hormones and behavior <br />Many hormones affect the CNS <br />Changes in the normal mixture of hormones significantly alters intellectual capabilities, memory, learning and emotional states <br />SECTION 18-11 Aging and Hormone Production <br />Endocrine system <br />Few functional changes with age <br />Chief change is a decline in concentration of reproductive hormones <br />You should now be familiar with: <br />The major chemical classes and general mechanisms of hormones. <br />The location and structure of the pituitary gland, and its structural and functional relationships with the hypothalamus. <br />The location and structure of each of the endocrine glands. <br />The hormones produced by each of the endocrine glands, and the functions of those hormones. <br />You should now be familiar with: <br />The functions of the hormones produced by the kidneys, heart, thymus, testes, ovaries and adipose tissue. <br />How hormones interact to produce coordinated physiological responses. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109839389681014539?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1098393803850252542004-10-21T14:23:00.000-07:002004-10-21T14:23:23.850-07:00Chapter 18, part 2 <br />The Endocrine System <br />Hypophyseal portal system <br />All blood entering the portal system will reach the intended target cells before returning to the general circulation <br />Figure 18.7 The Hypophyseal Portal System <br />Figure 18.8 Feedback control of Endocrine Secretion <br />Figure 18.8 Feedback control of Endocrine Secretion <br />Hormones of the adenohypophysis <br />Thyroid stimulating hormone (TSH) <br />Triggers the release of thyroid hormones <br />Thyrotropin releasing hormone promotes the release of TSH <br />Adrenocorticotropic hormone (ACTH) <br />Stimulates the release of glucocorticoids by the adrenal gland <br />Corticotrophin releasing hormone causes the secretion of ACTH <br />Hormones of the adenohypophysis <br />Follicle stimulating hormone (FSH) <br />Stimulates follicle development and estrogen secretion in females and sperm production in males <br />Leutinizing hormone (LH) <br />Causes ovulation and progestin production in females and androgen production in males <br />Gonadotropin releasing hormone (GNRH) promotes the secretion of FSH and LH <br />Hormones of the adenohypophysis <br />Prolactin (PH) <br />Stimulates the development of mammary glands and milk production <br />Growth hormone (GH or somatotropin) <br />Stimulates cell growth and replication through release of somatomedins or IGF <br />Growth-hormone releasing hormone (GH-RH) <br />Growth-hormone inhibiting hormone (GH-IH) <br />Melanocyte stimulating hormone (MSH) <br />May be secreted by the pars intermedia during fetal development, early childhood, pregnancy or certain diseases <br />Stimulates melanocytes to produce melanin <br />The posterior lobe of the pituitary gland (neurohypophysis) <br />Contains axons of hypothalamic nerves <br />neurons of the supraoptic nucleus manufacture antidiuretic hormone (ADH) <br />Decreases the amount of water lost at the kidneys <br />Elevates blood pressure <br />The posterior lobe of the pituitary gland (neurohypophysis) <br />Neurons of the paraventricular nucleus manufacture oxytocin <br />Stimulates contractile cells in mammary glands <br />Stimulates smooth muscle cells in uterus <br />Figure 18.9 Pituitary Hormones and Their Targets <br />SECTION 18-4 The Thyroid Gland <br />The thyroid <br />Lies near the thyroid cartilage of the larynx <br />Two lobes connected by an isthmus <br />Figure 18.11 The Thyroid Gland <br />Figure 18.11 The Thyroid Gland <br />Thyroid follicles and thyroid hormones <br />Thyroid gland contains numerous follicles <br />Release several hormones such as thyroxine (T4) and triiodothyronine (T3) <br />Thyroid hormones end up attached to thyroid binding globulins (TBG) <br />Some are attached to transthyretin or albumin <br />Figure 18.12 The Thyroid Follicles <br />Figure 18.12 The Thyroid Follicles <br />Thyroid hormones <br />Held in storage <br />Bound to mitochondria, thereby increasing ATP production <br />Bound to receptors activating genes that control energy utilization <br />Exert a calorigenic effect <br />Cells of the thyroid gland <br />C cells produce calcitonin <br />Helps regulate calcium concentration in body fluids <br />Figure 18.13 Thyroid Disorders <br />SECTION 18-5 The Parathyroid Glands <br />Four parathyroid glands <br />Embedded in the posterior surface of the thyroid gland <br />Chief cells produce parathyroid hormone (PTH) in response to lower than normal calcium concentrations <br />Parathyroid hormones plus calcitriol are primary regulators of calcium levels in healthy adults <br />Figure 18.14 The Parathyroid Glands <br />Figure 18.15 The Homeostatic Regulation of Calcium Ion Concentrations <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109839380385025254?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1097875175736254842004-10-15T14:19:00.000-07:002004-10-15T14:19:35.736-07:00Chapter 2, part 1 <br />The Chemical Level of Organization <br />Learning Objectives <br />Describe an atom and compare the ways atoms combine to form molecules. <br />Distinguish among the types of chemical reactions that are important to physiology. <br />Describe the role of enzymes in metabolism. <br />Distinguish between organic and inorganic compounds. <br />Explain the importance of water, pH and buffers to living systems. <br />Discuss the structures and functions of carbohydrates, lipids, proteins, nucleic acids and high energy compounds. <br />SECTION 2-1 Atoms, Molecules and Bonds <br />Atoms are the smallest stable units of matter <br />Subatomic particles <br />Protons = positive charge; weight of approximately 1 Dalton <br />Neutrons = no charge; weight similar to protons <br />Electrons = negative charge; weigh 1/1836th Dalton <br />Protons and neutrons are found in the nucleus; electrons occupy electron cloud <br />Atomic number = proton number; atomic mass = protons and neutrons <br />Isotopes are elements with similar numbers of protons but different numbers of neutron <br />Figure 2.1 Hydrogen Atoms <br />Electrons occupy a series of energy levels or electron shells. <br />The outermost electron shell determines the reactivity of the element. <br />Figure 2.2 Atoms and Energy Levels <br />Atoms combine through chemical reactions <br />Molecule = a chemical structure consisting of molecules held together by covalent bonds <br />Compound = a chemical substance composed of atoms of two or more elements <br />There are three types of bond: Ionic, covalent, and hydrogen <br />Ionic = attraction between positive cations and negative anions <br />Figure 2.3 Ionic Bonding <br />Covalent bonds exist between atoms that share electrons to form a molecule <br />Double covalent bond <br />Non-polar covalent bond <br />Polar covalent bond <br />Hydrogen bonds are weak forces that affect the shape and properties of compounds <br />Polar covalent bonds that occur when hydrogen covalently bonds with another element <br />Figure 2.5 Polar Covalent Bonds and the Structure of Water <br />Figure 2.6 Hydrogen Bonds <br />Matter and chemical notation <br />Matter can exist as a solid, liquid or gas <br />Depends on the interaction of the component atoms or molecules <br />Molecular weight is the sum of the atomic weights of the component atoms <br />Chemical notation <br />Short-hand that describes chemical compounds and reactions <br />See table 2.2 for examples of chemical notation <br />SECTION 2-2 Chemical Reactions <br />A chemical reaction occurs when reactants combine to generate one or more products <br />All chemical reactions in the body constitutes metabolism <br />Metabolism provides for the capture, storage and release of energy <br />Basic energy concepts <br />Work = movement of an object or change in its physical structure <br />Energy = the capacity to perform work <br />Kinetic energy is energy of motion <br />Potential energy is stored energy resulting from position or structure <br />Conversions are not 100% efficient, resulting in release of heat <br />Metabolism <br />Types of reaction <br />Decomposition <br />Synthesis <br />Exchange <br />Metabolism is the sum of all reactions <br />Through catabolism cells gain energy (break down of complex molecules) <br />Anabolism uses energy (synthesis of new molecules) <br />Reversible reactions <br />All reactions are theoretically reversible <br />At equilibrium the rates of two opposing reactions are in balance <br />Anabolism = catabolism <br />Enzymes, energy and chemical reactions <br />Activation energy is the amount of energy needed to begin a reaction <br />Enzymes are catalysts <br />Reduce energy of activation without being permanently changed or used up <br />Promote chemical reactions <br />Figure 2.7 Enzymes and Activation Energy <br />SECTION 2-3 Inorganic Compounds <br />Nutrients and Metabolites <br />Nutrients are essential chemical compounds obtained from the diet <br />Metabolites are molecules synthesized or broken down inside the body <br />These can be classified as organic or inorganic compounds <br />Organic compounds have carbon and hydrogen as their primary structural component <br />Inorganic compounds are not primarily carbon and hydrogen <br />Water and its properties <br />Water is the most important constituent of the body <br />Solution is a uniform mixture of two or more substances <br />Solvent is the medium in which molecules of solute are dispersed <br />Water is the solvent in aqueous solutions <br />Figure 2.8 Water molecules and solutions <br />Electrolytes undergo ionization <br />Compounds that interact readily with water are hydrophilic <br />Compounds that do not interact with water are hydrophobic <br />pH is a measure of the concentration of hydrogen ions solution <br />Neutral <br />Acidic <br />Basic <br />Acids and Bases <br />Acids release hydrogen ions into solution <br />Bases remove hydrogen ions from solution <br />Strong acids and strong bases ionize completely <br />Weak acids and weak bases do not ionize <br />Figure 2.9 pH and Hydrogen Ion Concentration <br />Salts and buffers <br />Salt = an electrolyte whose cation is not hydrogen and whose anion is not hydroxide <br />Buffers remove or replace hydrogen ions in solution <br />Buffer systems maintain the pH of body fluids <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109787517573625484?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1097874890987799982004-10-15T14:14:00.000-07:002004-10-15T14:14:50.986-07:00Here is 18-1. More detail to follow in class <br /> <br />Chapter 18, part 1 <br />The Endocrine System <br />Learning Objectives <br />Compare the major chemical classes and general mechanisms of hormones. <br />Describe the location and structure of the pituitary gland, and explain its structural and functional relationships with the hypothalamus. <br />Describe the location and structure of each of the endocrine glands. <br />Learning Objectives <br />Identify the hormones produced by each of the endocrine glands and specify the functions of those hormones. <br />Describe the functions of the hormones produced by the kidneys, heart, thymus, testes, ovaries and adipose tissue. <br />Explain how hormones interact to produce coordinated physiological responses. <br />SECTION 18-1 Intercellular Communication <br />Endocrine versus Nervous system <br />Nervous system performs short term crisis management <br />Endocrine system regulates long term ongoing metabolic <br />Endocrine communication is carried out by endocrine cells releasing hormones <br />Alter metabolic activities of tissues and organs <br />Target cells <br />Paracrine communication involves chemical messengers between cells within one tissue <br />SECTION 18-2 An Overview of the Endocrine System <br />Endocrine system <br />Includes all cells and endocrine tissues that produce hormones or paracrine factors <br />Figure 18.1 The Endocrine System <br />Hormone structure <br />Amino acid derivatives <br />Structurally similar to amino acids <br />Peptide hormones <br />Chains of amino acids <br />Lipid derivatives <br />Steroid hormones and eicosanoids <br />Figure 18.2 A Structural Classification of Hormones <br />Hormones can be <br />Freely circulating <br />Rapidly removed from bloodstream <br />Bound to transport proteins <br />Mechanisms of hormone action <br />Receptors for catecholamines, peptide hormones, eicosanoids are in the cell membranes of target cells <br />Thyroid and steroid hormones cross the membrane and bind to receptors in the cytoplasm or nucleus <br />Figure 18.3 G Proteins and Hormone Activity <br />Figure 18.4 Hormone Effects on Gene Activity <br />Control of endocrine activity <br />Endocrine reflexes are the counterparts of neural reflexes <br />Hypothalamus regulates the activity of the nervous and endocrine systems <br />Secreting regulatory hormones that control the anterior pituitary gland <br />Releasing hormones at the posterior pituitary gland <br />Exerts direct neural control over the endocrine cells of the adrenal medullae <br />Figure 18.5 Three Methods of Hypothalamic Control over the Endocrine System <br />SECTION 18-3 The Pituitary Gland <br />Hypophysis <br />Releases nine important peptide hormones <br />All nine bind to membrane receptors and use cyclic AMP as a second messenger <br />Figure 18.6 The Anatomy and Orientation of the Pituitary Gland <br />The anterior lobe (adenohypophysis) <br />Subdivided into the pars distalis, pars intermedia and pars tuberalis <br />At the median eminence, neurons release regulatory factors through fenestrated capillaries <br />Releasing hormones <br />Inhibiting hormones <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109787489098779998?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1097183293155476692004-10-07T14:07:00.001-07:002004-10-07T14:08:13.156-07:00SECTION 17-4 Equilibrium and Hearing <br />Hearing <br />The special sense of hearing and equilibrium are provided by the inner ear which is a receptor complex located in the peterous part of the temporal bone of the skull <br />Equilibrium sensations inform us of the position of the head in space <br />Hearing enables us to detect and interpret sound waves <br />The basic mechanisms for both senses are hair cells, a mechanical sensors <br />The anatomy of the ear <br />Three anatomical regions <br />External ear <br />Middle ear <br />Inner ear <br />Both equilibrium and hearing are provided by receptors of the inner ear <br />Anatomy of the ear – External Ear: visible portion, collects and directs sound toward the middle ear: compostion <br />Auricle or pinnae surrounds the ear <br />External acoustic meatus ends on tympanic membrane <br />External ear <br />Includes the fleshy and cartilaginous auricle <br />This surrounds the external acoustic canal or ear canal <br />This is the passage way that ends on the tympanic membrane <br />Protective features found here in the form of ceruminous glands which produce cerumen <br />Figure 17.20 The Anatomy of the Ear <br />Middle ear <br />Communicates with pharynx via pharyngotympanic membrane <br />Middle ear encloses and protects the auditory ossicles <br />Figure 17.21 The Middle Ear <br />Middle Ear <br />Also called the tympanic cavity <br />It is separated from the external acoustic canal by the tympanic membrane <br />Communicates with the nasopharnyx through the auditory tube and the mastoid air cells <br />Also called the pharyngotympanic tube which permits equalization of air <br />Auditory Ossicles <br />Hammer <br />Anvil <br />Stirrup <br />What are the articulations? <br />Malleus attaches to the tympanic membrane <br />The stapes articulates on the oval window <br />How is sound carried? <br />It is the articulations of the hammer on the vibrating tympanic membrane that is passed to the stapes which moves up and down on the oval window <br />It is really a rocking motion on the stapes <br />This is a level design that amplifies sound because the tympanic membrane is heavier then the membrane of the oval window <br /> <br />What is the job of the inner ear? <br />The sense of equilibrium and hearing are provided by receptors of the inner ear <br />Remember that these receptors lie within a collection of fluid filled chambers known as the membranous labyrinth which is filled with an electrolytic soln called endolymph <br />Inner ear: bony labyrinth: function <br />Bony labyrinth surrounds and protects membranous labyrinth <br />Between the bony and membranous labyrinth is found perilymph (CSF) <br />What are the divisions of the bony labyrinth? <br />Vestibule: pair of membraneous sacs <br />Saccule <br />uticle <br />Semicircular canals <br />stimulated by rotation of the head <br />Cochlea <br />Provide the sense of hearing <br />Figure 17.22 The Inner Ear <br />Components of the inner ear: quick review: are what? <br />Vestibule contains the utricle and saccule <br />Semicircular canals contain the semicircular ducts <br />Cochlea contains the cochlear duct <br />Windows: two types: functions: <br />Round window separates the perilymph from the air spaces of the middle ear <br />Oval window connected to the base of the stapes <br />Basic receptors of inner ear are hair cells <br />Provide information about the direction and strength of stimuli <br />Receptors of the inner ear <br />These sensory receptors are called hair cells <br />These cells are surrounded by supporting cells and are monitored by sensory afferent fibers <br />The hair like structures have two components <br />Stereocilia: 80 – 100 present <br />Kinocilium: single large cilia <br />Only move when external forces push against them <br />What kind of information will these cilia provide? <br />Direction and strength of the mechanical stimulation and response varies depending on the location of the cilia <br />Types of stimulation can include: <br />Gravity or acceleration in the vestibule <br />Rotation in the semicircular canal <br />Sound in the cochlea <br /> <br />How is equilibrium information provided? <br />Provided by receptors of the vestibular complex <br />The information provided is based on rotational movements of the head <br />Thus the saccule and the utricle convey information with respect to gravity <br />They are stimulated by sudden acceleration (stop or start) <br /> <br />The semicircular ducts <br />Thus the sensory receptors are quiet during non movement <br />What is this movement? <br />The kinocilia and the sterocilia are embeded in the cupula <br />Cupula floats on the endolymph <br />The movement of ones head distorts the receptor processes <br />Movement is based on direction <br />When there is no further movement, the cupula returns to the rest position <br />Thus there is analysis of motion in three planes <br /> <br />What is the job of Utricle and Saccule? <br />Both provide information about equilibrium whether or not the body is stationary or moving <br />Equilibrium: The whole structure è otolith <br />Anterior, posterior and lateral semicircular ducts are continuous with the utricle <br />Each duct contains an ampulla with a gelatinous cupula and associated kinocilia and sterocilia (review) <br />Saccule and utricle connected by a passageway continuous with the endolymphatic duct <br />Terminates in the endolymphatic sac <br />Saccule and utricle have hair cells clustered in an oval structure called the maculae <br />Cilia contact the statoconia ( calcium carbonate crystals) <br />Figure 17.23 The Vestibular Complex <br />Figure 17.23 The Vestibular Complex <br />Figure 17.23 The Vestibular Complex <br />Vestibular neural pathway: How is monitoring achieved? <br />Hairs of the vestribular and semicircular ducts are monitored by sensory neurons located in the vestibular ganglia <br />Axons form the vestibular branch of the vestibular cocohlear nerve (VIII) <br />Synapses within the vestibular nuclei between the pons and the medulla oblongata <br />Job functions; 4 of them <br />Integrating sensory information about balance and equilibrium that arrives from both sides of the head <br />Relay information from the vestibular complex to the cerebellum <br />Relay information from the vestibular complexd to the cerebral cortex for a conscious position of position of head <br />Send motor commands to nuclei in brain stem and spinal cord <br /> <br />What kind of information is sent? <br />Reflexive motor commands that are issued are distributed to motor nuclei for cranial nerves III, IV, VI, and XI <br />Descend down the vestibularspinal tracts <br />Adjust muscle tone <br />Figure 17.24 Pathways for Equilibrium Sensation <br />Hearing <br />Cochlear duct lies between the vestibular duct and the tympanic duct <br />Hair cells of the cochlear duct lie within the Organ of Corti <br />Intensity is the energy content of a sound <br />Measured in decibels <br />Figure 17.25 The Cochlea <br />Figure 17.26 The Organ Of Corti <br />Hearing <br />The receptors of the cochlear duct provide the sense of hearing that enables us to detect soft sounds <br />Hair cells responsible for picking up this auditory sound <br />Location prevents them from responding to any other stimuli <br />Whole process is based on pressure waves <br />This is the fluctuations of perilymph which determine the frequency and intensity <br />Pathway of sound <br />Sound waves travel toward tympanic membrane, which vibrates <br />Auditory ossicles conduct the vibration into the inner ear <br />Tensor tympani and stapedius muscles contract to reduce the amount of movement when loud sounds arrive <br />Movement at the oval window applies pressure to the perilymph of the cochlear duct <br />Pressure waves distort basilar membrane <br />Hair cells of the Organ of Corti are pushed against the tectoral membrane <br />It is the distortion of the basiliar membrane pressing on the tectorial membrane that results in the generation of an action potential in the receptors <br />Figure 17.28 Sound and Hearing <br />Figure 17.29 Sound and Hearing <br />Neural pathway; location of the nerve fibers <br />Sensory neurons of hearing are located in the spiral ganglion of the cochlea <br />Afferent fibers form the cochlear branch of cranial nerve VIII <br />Synapse at the cochlear nucleus <br />The steps: <br />Sound waves arrive at the tympanic membrane <br />Tympanic membrane causes displacement of auditory ossciles <br />Stapes moves against the oval window <br />Pressure waves distort the basilar membrane <br />Vibration of the basilar membrane <br />Relay information along the afferent branch of the Vestibularcodhlear nerve VIII to the cochlear nucleus then crosses to opposite side of the brain to the inferior colliculus <br />Then to the thalamus and finally to the auditory cortex of the temporal lobe <br />You should now be familiar with: <br />The sensory organs of smell, and the olfactory pathways in the brain. <br />The accessory and internal structures of the eye, and their functions. <br />How light stimulates the production of nerve impulses, and the visual pathways. <br />The structures of the external and middle ear and how they function. <br />The parts of the inner ear and their roles in equilibrium and hearing. <br />The pathways for the sensations of equilibrium and hearing. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109718329315547669?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1096591686131217612004-09-30T17:47:00.000-07:002004-09-30T17:48:06.130-07:00Chapter 17, part 2 <br />The Special Senses <br />Fibrous tunic <br />Defined as the outermost layer of the eye <br />Provides mechanical support and protection <br />Serves as an attachment site for the extrinstic muscles of the eyes <br />Contain aids for focusing <br /> <br />Outer surface <br />Large part of the outer surface is called the sclera of the white of the eye <br />Composed of dense connective tissue containing collage and elastic fibers <br />Thickest over the posterior surface of the eye and thinnest on the anterior surface of the eye near the optic nerve <br />Six extrinsic eye muscles insert on the sclera of the eye <br /> <br /> <br />Sclera composition <br />Small blood vessels and nerves that penetrate into the internal structures of the eye <br />The cornea is continuous with the sclera and the border between the sclera and the cornea is called the limbus <br /> <br />Cornea composition <br />No blood vessels <br />Nutrients and oxygen are obtained from tears <br />Also has many free nerve endings <br />Vascular tunic <br />Composition: <br />Blood vessels <br />Lymph vessels <br />Intristic eye muscles <br /> <br />Function: <br />Provides a route for blood and lymph vessels <br />Regulates the amount of light that enters the eye <br />Secreting and reabsorbing the aqueous humor <br />Control the shape of the lens <br /> <br />More on composition <br />Iris <br />Ciliary body <br />choroid <br />Iris <br />Contains <br />Blood vessels <br />Pigment cells <br />Two layers of smooth muscle tissue which regulate the diameter of the pupil, these sphincter muscles are under autonomic control <br />Pupillary constrictor muscles <br />Pupillary dilator muscles <br /> <br />The body of the iris <br />High vascularized pigmented loose connective tissue <br />The anterior portion contains the melanocytes which are responsible for the color on the surface of the eye <br />Ciliary Body <br />The iris is anchored to the ciliary body at its periphery <br />This ciliary body begins at the junction of the cornea and the sclera and ends at the orta serrata <br />The bulk of this ciliary body consists of ciliary muscle <br />Suspensory ligaments attach to the ciliary processes <br /> <br /> <br />Choroid <br />Has an extensive capillary network that delivers oxygen to the retina <br /> <br />Neutral Tunic <br />Also called the retina <br />Inner most portion of the eye <br /> <br />Composition <br />Outer most layer called the pigment part <br />Inner most layer called the neural part <br />Job functions <br />Pigment part absorbs the light the passes through the neutral part and prevents light from bouncing back to the neural part <br />The neural part contains blood vessels and processes preliminary visual information <br />Extent of the layers <br />Pigment part extends over the ciliary body and iris <br />The neural part extend just to the orta serrata <br /> <br />Retina: organization: the photoreceptors <br />Retina contains rods and cones <br />Cones densely packed at fovea (center of the macula lutea) <br />Retinal pathway <br />Rods and cones synapse with 6 million bipolar neurons which pass on information to ganglion cells, to the brain via the optic nerve <br />Axons of ganglion cells converge at blind spot (optic disc) <br />Horizontal cells and amacrine cells modify the signal passed along the retinal neurons by facilitation or inhibition <br />What are the jobs of the rods and cones? <br />The rods do not discriminate colors of light <br />The cones provides us with color vision <br />Three cone types determine the color you see <br />Also give us sharper clear images <br />However, they require more intense light to be active <br /> <br />Rod and cone distribution <br />125 million rods are found along the periphery of the retina <br />6 million cones span the posterior surface <br />Most found near the macula lutea <br />This region contain NO rods! <br />The highest concentration of the cones occurs at the center of the muscula lutea and this region is called the fovea <br />Region of sharpest vision <br />Optic disc <br />The axons from 1 million ganglion cells converge on the optic disc <br />This disc is the origin of cranial nerve II which proceeds to the diencephalon <br />The central retinal artery and vein can be found here <br />The optic disc has no photoreceptors <br />This area of contact is called the blind spot <br /> <br />Chamber of the eye <br />Anterior cavity <br />Anterior chamber <br />Posterior chamber <br />Posterior chamber <br /> <br />Aqueous humor <br />A fluid which circulates within the anterior cavity passing from the posterior chamber to the anterior chamber through the pupil <br />Formed by cells of the ciliary processes <br />Similar to CSF <br />This creates intraocular pressure which forces the neural layer against the pigmented layer <br />Returns from the posterior chamber back to the anterior chamber by passing through the canal of Schlemm <br />This is then passed onto the veins of the sclera <br /> <br /> <br />Viterous Body <br />Posterior portion of the eye contains the viterous body <br />Gelatin like in structure <br />Stabilizes the shape of the eye <br />Additional physical support to the retina <br />Fluid is made up of collagen and proteoglycans (these resemble cellulose like materials) <br />Never replaced <br />Figure 17.6 The Organization of the Retina <br />Eye anatomy: pause and review <br />Ciliary body and lens divide the anterior cavity of the eye into posterior (vitreous) cavity and anterior cavity <br />Anterior cavity further divided <br />anterior chamber in front of eye <br />posterior chamber between the iris and the lens <br />Figure 17.8 The Circulation of Aqueous Humor <br />Fluids in the eye <br />Aqueous humor circulates within the eye <br />diffuses through the walls of anterior chamber <br />passes through canal of Schlemm <br />re-enters circulation <br />Vitreous humor fills the posterior cavity. <br />Not recycled – permanent fluid <br />Lens <br />Posterior to the cornea and forms anterior boundary of posterior cavity <br />Posterior cavity contains vitreous humor <br />Lens helps focus <br />Light is refracted as it passes through lens <br />Accommodation is the process by which the lens adjusts to focus images <br />Normal visual acuity is 20/20 <br />Figure 17.9 Image Formation <br />Figure 17.10 Accommodation <br />Figure 17.11 Visual Abnormalities <br />Visual physiology <br />Rods – respond to almost any photon <br />Cones – specific ranges of specificity <br />Figure 17.13 Rods and Cones <br />Photoreceptor structure <br />Outer segment with membranous discs <br />Narrow stalk connecting outer segment to inner segment <br />Light absorption occurs in the visual pigments <br />Derivatives of rhodopsin <br />Figure 17.14 Photoreception <br />Figure 17.14 Photoreception <br />Figure 17.15 Bleaching and Regeneration of Visual Pigments <br />Color sensitivity <br />Integration of information from red, blue and green cones <br />Colorblindness is the inability to detect certain colors <br />retinal adaptation <br />Dark adapted – most visual pigments are fully receptive to stimulation <br />Light adapted – pupil constricts and pigments bleached. <br />the visual pathway <br />Large M-cells monitor rods <br />Smaller more numerous P cells monitor cones <br />Figure 17.18 Convergence and Ganglion Cell Function <br />Seeing in stereo <br />Vision from the field of view transfers from one side to the other while in transit <br />Depth perception is obtained by comparing relative positions of objects from the two eyes <br />Figure 17.19 The Visual Pathways <br />Visual circadian rhythm <br />Input to suprachiasmic nucleus affects the function of the brainstem <br />Circadian rhythm ties to day-night cycle, and affects metabolic rates <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109659168613121761?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1096591332022861402004-09-30T17:37:00.000-07:002004-09-30T17:48:50.173-07:00Chapter 17, part 1 <br />The Special Senses <br />Learning Objectives <br />Describe the sensory organs of smell, and trace the olfactory pathways to their destination in the brain. <br />Identify the accessory and internal structures of the eye, and explain their function. <br />Explain how light stimulates the production of nerve impulses, and trace the visual pathways to their destination in the brain. <br />Describe the structures of the external and middle ear and explain how they function. <br />Learning Objectives <br />Describe the parts of the inner ear and their roles in equilibrium and hearing. <br />Trace the pathways for the sensations of equilibrium and hearing to their destinations in the brain. <br />SECTION 17-1 Olfaction <br />What is the composition <br />The sense of smell as defined as the process called olfaction <br />These organs are located in the nasal cavity on either side of the nasal septum <br />Composition <br />Two layers <br />Olfactory epithelium <br />Here are located the olfactory receptors <br />Basal cells <br />Stem cells or supporting cells <br /> <br />Where is this epithelium found? <br />Inferior surface of the cribriform plate <br />Superior portion of the perpendicular plate <br />Superior nasal conchae <br />Underlying portions contain the olfactory glands <br />Olfactory receptors <br />They are considered to be highly modified neurons <br />The exposed tip of the neuron forms a bulb which extends beyond the surface of the epithelium and extends into the mucus <br />Here the cilia are found and have exposed surfaces for picking up chemicals <br /> <br />Where does olfaction occur? <br />Occurs on the surface of the cilia <br />There are special receptors called odorant binding proteins <br />The chemicals which bring about the response are called an ordorant <br />Ordorants trigger a chemical response through secondary messengers <br /> <br />Olfactory pathways <br />It is believed that as few as four molecules can trigger an response <br />Not all information will reach the olfactory centers <br />There is significant olfactory central adaptation <br />There is two or more axons which bundle themselves together after they emerge from the cribiform plate and pass the cerebrum <br />They also reach the hypothalamus and limbic system <br />The olfactory information that is collected, does not synapse in the thalamus before it goes to the cerebrum <br />Olfactory Discrimination <br />2000 – 400 smells <br />All olfactory cells look the same <br />50 primary smells <br />Pattern of receptor activity are interpreted determine the "smell" <br />Pattern determination fails with age <br />Olfactory organs: Review <br />Contain olfactory epithelium with olfactory receptors, supporting cells, basal cells <br />Olfactory receptors are modified neurons <br />Surfaces are coated with secretions from olfactory glands <br />Olfactory reception involved detecting dissolved chemicals as they interact with odorant binding proteins <br />Figure 17.1 The Olfactory Organs <br />Olfaction <br />Olfactory pathways <br />No synapse in the thalamus for arriving information <br />Olfactory discrimination <br />Can distinguish thousands of chemical stimuli <br />CNS interprets smells by pattern of receptor activity <br />Olfactory receptor population shows considerable turnover <br />Number of receptors declines with age <br />SECTION 17-2 Gustation <br />The beginning: where do we find <br />Taste receptors are distributed over the surface of the tongue and the adjacent portions of the pharynx and the larynx <br />The most important ones are found on the tongue <br />Adults have 3000 taste buds <br />Where find on the tongue? Found everywhere on tongue? <br />Three types of lingual papillae <br />Filiform <br />Fungiform <br />Circumvallate <br /> <br />Filiform <br />No taste receptors found here <br />These provide friction to help move food along <br /> <br />Fungiform <br />Contains 5 taste buds <br /> <br />Cicumvallate <br />Largest of the papillae <br />Contains about 100 taste buds <br />Form a V with the posterior margin of the tongue <br /> <br />How are taste buds put together? <br />They are placed in recessed spaces to isolate them from the rest of contents of the rest of the mouth <br />There are four different cell types within a taste bud <br />Stage one are the basal cells for repair and replacement <br />Stage four are the gustratory cells which are responsible for the taste <br />Each taste bud has a pore for fluids to enter <br />Gustatory cells last only 10 days <br />Taste receptors Quick review <br />Clustered in taste buds <br />Associated with lingual and circumvallate papillae <br />Contain basal cells which appear to be stem cells <br />Gustatory cells extend taste hairs or cilia through a narrow taste pore <br />Figure 17.2 Gustatory Reception <br /> <br />Gustatory pathways <br />Taste buds are monitored by cranial nerves VII, IX, and X <br />Synapse within the solitary nucleus of the medulla oblongata and the medial lemniscus <br />There the neurons axons that carry somatic sensory information on touch, pressure, and proprioception <br />Then on to the thalamus and finally the primary sensory cortex <br />When is there a conception perception? <br />That of taste is produced as the information received is correlated with other sensory data <br />This includes information about texture of the food <br />Other data is carried by the V cranial nerve <br />Sensitive to taste is enhanced by olfaction <br /> <br />Gustatory discrimination <br />Primary taste sensations are defined as being: <br />Sweet, sour, salty, bitter <br />Receptors also exist for umami and water <br />Taste sensitivity shows significant individual differences, some of which are inherited <br />The number of taste buds declines with age <br />What is umani? <br />Pleasant taste depending on the presence of amino acids <br />They are found in the circumvalatte papillae <br /> <br />Water receptors? <br />Found in the pharynx <br />Processed in the hypothalamus <br />It is known that it affects the production of ADH <br /> <br />What is the mechanism of gustatory? <br />Dissolved chemicals must come in contact with receptors <br />Different receptors for different tastes <br />The net is always a stimulation of sensory neurons from the taste receptors that produce an graded potential <br />Taste receptors adapt slowly but there is central adaptation reduces your sensitivity to a new taste presented <br /> <br />How do we define this threshold? <br />Two conditions <br />For unpleasant taste, the receptors respond more quickly <br />Sour tastes respond quickly <br />Sweet of salty is responding slower <br />But more sensitive to bitter, quinine compds <br /> <br />SECTION 17-3 Vision <br />Accessory structures of the eye; the divisions <br />Job function: <br />protection, lubrication, and support <br />Eyelids (palpebrae) separated by the palpebral fissure <br />Eyelashes <br />Tarsal glands <br />Lacrimal apparatus <br />The eyelids <br />Also called the palprebra <br />Keeps the surface of the eye lubricated and free from dust and debris <br />Capable of tight closure <br />The palprebra fissure separates the upper and lower eyelids <br />The eyelids are connected at the median and lateral canthus <br /> <br />Eyelashes <br />The eyelashes prevent foreign matter from reaching the eye <br />Did you know that there are small mites growing on your eyelids <br />Think of the contain of eyelash liner as a growth chamber for these bugs <br /> <br />Eyelashes and lubrication <br />We find that along the inner margin of the lid is a gland called the tarsal gland <br />The oil prevents the lids from sticking together <br />There are also lacrimal glands that produce secretions that are gritty <br />All glands subject to infection <br /> <br />Function of Lubrication <br />Keeps the conjunctival surface clean and moist <br />Tears reduce friction and prevent bacterial infections <br />Provide nutrients and oxygen portions to the conjunctival epithelium <br /> <br />Lacrimal appratus construction <br />Lacrimal glands and associated ducts <br />Lacrimalcanaliculi <br />Lacrimal sac <br />Nasolacrimal duct <br />How are demands meet? <br />Nutrient and oxygen demands are met by diffusion from the lacrimal secretions <br />Lacrimal apparatus: function <br />Secretions from the lacrimal gland contain lysozyme <br />Provides the key incredients and most of the volume of the tears that bathe the conjunctival surface <br />Tears form in the lacrimal glands, wash across the eye and collect in the lacrimal lake <br />Then pass through the lacrimal punctae, lacrimal canaliculi, lacrimal sac and nasolacrimal duct when these secretions drain from the eye itself <br />What is produced? <br />About 1 mL of tears/day <br />These secretions then mix with oils from accessory glands and form and oil slick that assists in lubrication and the slowly of evaporation <br />What does blinking do? <br />Blinking provides a sweeping action across the surface of the eye <br />Figure 17.3 Eternal Features and Accessory Structures of the Eye <br />external structures of the eye <br />Conjunctiva covers most of inner portion of the eyelids and the outer surface of the eye <br />This is really a mucus membrane made of two parts: <br />Palpebral conjunctiva <br />Ocular conjunctive <br />What is the cornea? <br />Cornea is transparent anterior portion in which light passes through <br />The occur conjunctiva ends here <br />This is covered by corneal epithelium <br />What is conjunctivitis? <br />Pink eye <br />Damage to the conjunctival surface <br />Characterized by dilation of blood vessels deep to the conjunctival eipthelium <br />The eye <br />Three layers <br />Outer fibrous tunic <br />Sclera, cornea, limbus <br />Middle vascular tunic <br />Iris, ciliary body, choroid <br />Inner nervous tunic <br />Retina <br />Figure 17.4 The Sectional Anatomy of the Eye <br />Structures <br />Posterior cavity <br />Viterous humor <br />Contains the retinal <br />Anterior cavity <br />Aqueous humor <br />Orbial fat <br />internal structures of the eye <br />Ciliary body <br />Ciliary muscles and ciliary processes, which attach to suspensory ligaments of lens <br />Retina <br />Outer pigmented portion <br />Inner neural part <br />Rods and cones <br />Figure 17.4 The Sectional Anatomy of the Eye <br />Figure 17.5 The Pupillary Muscles <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109659133202286140?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1096220360110540532004-09-26T10:36:00.000-07:002004-09-26T10:39:20.110-07:00SECTION 16-3 The Parasympathetic Division <br />Parasympathetic division: <br />Preganglionic neurons in the brainstem and sacral segments of spinal cord <br />Ganglionic neurons in peripheral ganglia located within or near target organs <br />Figure 16.7 The Organization of the Parasympathetic Division of the ANS <br />Organization and anatomy of the parasympathetic division <br />Preganglionic fibers leave the brain as cranial nerves III, VI, IX, X <br />Sacral neurons form the pelvic nerves <br />Figure 16.8 The Distribution of Parasympathetic Innervation <br />Parasympathetic activation <br />Effects produced by the parasympathetic division <br />relaxation <br />food processing <br />energy absorption <br />Neurotransmitters and parasympathetic functions <br />All parasympathetic fibers release ACh <br />Short-lived response as ACH is broken down by AChE and tissue cholinesterase <br />Postsynaptic membranes have two kinds of receptors <br />Muscarinic <br />Ach receptors respond to the poison <br />Nicotinic <br />Ach receptors which respond to nicotine <br />SECTION 16-4 Interactions Between the Sympathetic and Parasympathetic Divisions <br />Sympathetic and parasympathetic divisions <br />Sympathetic <br />Widespread influence on visceral and somatic structures <br />Parasympathetic <br />Innervates only visceral structures serviced by cranial nerves or lying within the abdominopelvic cavity <br />Dual innervation = organs that receive input from both systems <br />Summary: parasympathetic division <br />Parasympathetic division includes cranial nerves III, VII, IX, and X and sacral segments S2 – S4 <br />Ganglion are located near target organs <br />Divisions are cholinergic <br />Effects are brief and site restricted <br /> <br />Anatomy of dual message delivery <br />Sympathetic and parasympathetic systems intermingle to form autonomic plexuses <br />Cardiac plexus <br />Pulmonary plexus <br />Esophageal plexus <br />Celiac plexus <br />Inferior mesenteric plexus <br />Hypogastric plexus <br />Figure 16.9 The Autonomic Plexuses <br />Comparison of the two divisions <br />Important physiological and functional differences exist <br />Figure 16.10 Summary: The Anatomical Differences between the Sympathetic and Parasympathetic Divisions <br />SECTION 16-5 Integration and Control of Autonomic Functions <br />Visceral reflexes <br />Visceral reflex arcs are the simplest function of the ANS <br />Long reflexes (interneurons) <br />Short reflexes (bypassing CNS) <br />Parasympathetic reflexes govern respiration, cardiovascular function and other visceral activities <br />Figure 16.11 Visceral Reflexes <br />Higher levels of autonomic control <br />Activity in the ANS is controlled by centers in the brainstem that deal with visceral functioning <br />Figure 16.12 Levels of Autonomic Control <br />SNS and ANS organized in parallel <br />Integration occurs at the brainstem and higher centers <br />Figure 16.13 A Comparison of Somatic and Autonomic Function <br />SECTION 16-6 High Order Functions <br />Higher order functions <br />Are performed by the cerebral cortex and involve complex interactions <br />Involve conscious and unconscious information processing <br />Are subject to modification and adjustment over time <br />Memory <br />Short term or long term <br />Memory consolidation is moving from short term to long term <br />Amnesia is the loss of memory due to disease or trauma <br />Figure 16.14 Memory Storage <br />Consciousness <br />Deep sleep, the body relaxes and cerebral cortex activity is low <br />REM sleep active dreaming occurs <br />The reticular activating system (RAS) is important to arousal and maintenance of consciousness <br />Figure 16.16 The Reticular Activating System <br />SECTION 16-7 Brain Chemistry and Behavior <br />Neurotransmitters and the brain <br />Neurotransmitters and brain function <br />Changes in balance between neurotransmitters can profoundly alter brain function <br />Personality and self-awareness <br />Characteristics of the brain as an integrated system rather than one specific component <br />SECTION 16-8 Aging and the Nervous System <br />Age-related changes <br />Reduction in brain size and weight <br />Reduction in the number of neurons <br />Decrease in blood flow to the brain <br />Changes in synaptic organization of the brain <br />Intracellular and extracellular changes in CNS neurons <br />You should now be familiar with: <br />The organization of the autonomic nervous system. <br />The structures and functions of the sympathetic and parasympathetic divisions of the ANS. <br />The mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. <br />The effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. <br />The hierarchy of interacting levels of control in the ANS. <br />How memories are created, stored and recalled. <br />The effects of aging on the nervous system. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109622036011054053?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974842185014402004-09-23T14:26:00.001-07:002004-09-26T10:26:34.410-07:00Learning Objectives <br />Compare the organization of the autonomic nervous system with the somatic nervous system. <br />Describe the structures and functions of the sympathetic and parasympathetic divisions of the ANS. <br />Describe the mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. <br />Describe the effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. <br />Learning Objectives <br />Describe the hierarchy of interacting levels of control in the ANS <br />Explain how memories are created, stored and recalled. <br />Summarize the effects of aging on the nervous system. <br />SECTION 16-1 An Overview of the ANS <br />General information <br />Neural Integration II: The Autonomic Nervous System and Higher Order Functions <br />There are going to be two major goals here, compare: <br />The neural interactions that direct motor output <br />The subdivisions of the ANS based on structural and functional patters <br /> <br />Common ground <br />Both the somatic and autonomic nervous systems are efferent that carry motor commands to the skeletal system <br />In the somatic nervous system the commands form the CNS exert direct control over the the skeletal muscle <br />In the ANS motor neurons of the CNS synapse on visceral motor neurons in autonomic ganglion and it is through the ganglion that control is exerted <br /> <br />More <br />The visceral motor neurons of the CNS are known as preganglionic neurons and the axons are called prehanglionic fibers <br />Those that leave the ganglion are called postganglionic fibers <br /> <br /> <br />Somatic or visceral information input <br />Input can trigger visceral reflexes and these motor commands are distributed by the ANS <br />ANS (review) <br />Coordinates cardiovascular, respiratory, digestive, urinary and reproductive functions <br />Preganglionic neurons in the CNS send axons to synapse on ganglionic neurons in autonomic ganglia outside the CNS <br />Divisions of the ANS <br />Most often the divisions have opposing effects <br />However, some divisions are only controlled by one of the divisions <br />Sympathetic division (thoracolumbar, "fight or flight") <br />Thoracic and lumbar segments <br />Parasympathetic division (craniosacral, "rest and repose") <br />Preganglionic fibers leaving the brain and sacral segments <br />A general statement <br />The parasympathetic nervous system dominates under resting conditions <br />And the sympathetic nervous system kicks in under times of stress <br /> <br />Eneteric nervous system <br />Generally local control over digestive properties <br />But the activity can also be influenced by both the sympathetic and parasympathetic divisions <br />SECTION 16-2 The Sympathetic Division <br />Sympathetic division anatomy <br />Preganglionic neurons between segments T1 and L2 <br />Ganglionic neurons in ganglia near vertebral column <br />The preganlionic fibers are short and the postganglionic fibers are long <br />The job is to prepare the body for fight of flight responses <br />Specialized neurons in adrenal glands <br />Parasympathetic division <br />The preganlionic fibers originate in the brain stem and the sacral segments of the spinal cord <br />They synapse in ganglion which are close to the target organ <br />This means that the preganlionic fibers are long and the postganglionic fibers are short <br />Job is to conserve energy <br />This means that if you consume a heavy meals, the activity is for digestions, absorption, and waste removal <br />Figure 16.3 The Organization of the Sympathetic Division of the ANS <br />Sympathetic division <br />The division consists of preganglionic neurons that are located between segments T1 and L2 of the spinal cord <br />The cell bodies are located in the gray matter of the lateral gray horns of their axons axons enter the ventral root at three segments <br /> <br />Sympathetic chain ganglion <br />Can also be called paaravertebral ganglion or lateral ganglion <br />These are found on both sides of the vertebral column <br />Innervates body wall, inside the thoracic cavity, and head and limbs <br /> <br />Collateral ganglia <br />Prevertebral ganglia <br />Innervates tissues and organs in the abdominopelvic cavity <br /> <br /> <br />Adrenal medullae <br />The center of each adrenal gland <br />Neurotransmitters released directly into the blood stream <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Sympathetic chain ganglion <br />Preganglionic fibers that carry motor commands that target structures in the body wall, thoracic cavity, or in the head, neck, or limbs, it will synapse in one or more sympathetic chain ganglion <br />Postganglionic fibers paths will differ <br />Postganglionic fibers <br />These control effectors in the body wall, head, neck, limbs <br /> <br />Organization and anatomy of the sympathetic division <br />The T1 and L2 spinal segments contain sympathetic preganglionic fibers <br />These segments of T1-L2, ventral roots give rise to myelinated white ramus <br />Which then lead to sympathetic chain ganglia or in the adrenal medulla <br />Sympathetic chain ganglia <br />Two final routes <br />Postganglionic fibers which control visceral effectors in wall, head, neck, or limbs <br />Potganglionic fibers which innervate structures of the heart and lungs form sympathetic nerves <br /> <br /> <br />Summary <br />The cervical, inferior lumbar, and sacral chain receive preganglionic innervation by preganglionic fibers from spinal segments T1 – L2 and every spinal nerve receives a gray ramus from a ganglionic of the sympathetic chain <br />Only the thoracic and superior lumbar ganglion T1 – L2 receive preganglionic fibers from white rami <br />Every spibal nerve receives gray ramus from a ganglion of the sympathetic chain <br />Collateral Ganglia <br />Figure 16.5 The Distribution of Sympathetic Innervation <br />Postganglionic fibers <br />Rejoin spinal nerves and reach their destination by way of the dorsal and ventral rami <br />Those targeting structures in the thoracic cavity form sympathetic nerves <br />Go directly to their destination <br />Abdominopelvic viscera <br />Sympathetic innervation via preganglionic fibers synapse within collateral ganglia <br />Splanchic nerves <br />Abdominopelvic viscera <br />Celiac ganglion <br />Innervates stomach, liver, gall bladder, pancreas, spleen <br />Superior mesenteric ganglion <br />Innervates small intestine and initial portion of large intestine <br />Inferior mesenteric ganglion <br />Innervates kidney, urinary bladder, sex organs, and final portion of large intestine <br />Sympathetic activation <br />In crises, the entire sympathetic division responds <br />Sympathetic activation <br />Affects include increased alertness, energy and euphoria, increased cardiovascular and respiratory activities, elevation in muscle tone, mobilization of energy resources <br />Neurotransmitters and sympathetic function <br />Stimulation of sympathetic division has two distinct results <br />Release of ACh or NE at specific locations <br />Secretion of E and NE into general circulation <br />Most postganglionic fibers are adrenergic, a few are cholinergic or nitroxidergic <br />Two types of receptors are alpha receptors and beta receptors <br />Sympathetic ganglionic neurons end in telodendria studded with varicosities filled with neurotransmitter <br />Adrenal Medullae <br />Preganglionic fibers enter an adrenal gland and proceed to its center, which is called adrenal medulla <br />This is a sympathetic ganglion <br />Here hormones are released into the blood stream <br />Secret epinephrine and norepinephrine <br />Blood is the vehicle which carries these chemical messengers <br /> <br />Sympathetic summary of activation <br />Increased alertness <br />Feeling of energy <br />Increased cardiovascular and respiratory activity <br />Elevation of muscle tone <br />Mobilization of energy reserves, breakdown of glycogen in muscle and liver cells and the release of lipids from storage <br />Figure 16.6 Sympathetic Variosities <br />Sympathetic summary division. <br />Two sets of sympathetic chain ganglion <br />Thee collateral ganglion <br />Two adrenal medullae <br />Preganlionic fibers re short <br />Postganglionic fibers are long <br />Typical examples of divergence <br />Single neuron can control many visceral effectors <br />Preganglionic fibers release ACH <br />Post ganglionic fibers release NE <br />Works through secondary messengers <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597484218501440?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974832645715272004-09-23T14:26:00.000-07:002004-09-23T14:27:12.646-07:00Learning Objectives <br />Compare the organization of the autonomic nervous system with the somatic nervous system. <br />Describe the structures and functions of the sympathetic and parasympathetic divisions of the ANS. <br />Describe the mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. <br />Describe the effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. <br />Learning Objectives <br />Describe the hierarchy of interacting levels of control in the ANS <br />Explain how memories are created, stored and recalled. <br />Summarize the effects of aging on the nervous system. <br />SECTION 16-1 An Overview of the ANS <br />General information <br />Neural Integration II: The Autonomic Nervous System and Higher Order Functions <br />There are going to be two major goals here, compare: <br />The neural interactions that direct motor output <br />The subdivisions of the ANS based on structural and functional patters <br /> <br />Common ground <br />Both the somatic and autonomic nervous systems are efferent that carry motor commands to the skeletal system <br />In the somatic nervous system the commands form the CNS exert direct control over the the skeletal muscle <br />In the ANS motor neurons of the CNS synapse on visceral motor neurons in autonomic ganglion and it is through the ganglion that control is exerted <br /> <br />More <br />The visceral motor neurons of the CNS are known as preganglionic neurons and the axons are called prehanglionic fibers <br />Those that leave the ganglion are called postganglionic fibers <br /> <br /> <br />Somatic or visceral information input <br />Input can trigger visceral reflexes and these motor commands are distributed by the ANS <br />ANS (review) <br />Coordinates cardiovascular, respiratory, digestive, urinary and reproductive functions <br />Preganglionic neurons in the CNS send axons to synapse on ganglionic neurons in autonomic ganglia outside the CNS <br />Divisions of the ANS <br />Most often the divisions have opposing effects <br />However, some divisions are only controlled by one of the divisions <br />Sympathetic division (thoracolumbar, "fight or flight") <br />Thoracic and lumbar segments <br />Parasympathetic division (craniosacral, "rest and repose") <br />Preganglionic fibers leaving the brain and sacral segments <br />A general statement <br />The parasympathetic nervous system dominates under resting conditions <br />And the sympathetic nervous system kicks in under times of stress <br /> <br />Eneteric nervous system <br />Generally local control over digestive properties <br />But the activity can also be influenced by both the sympathetic and parasympathetic divisions <br />SECTION 16-2 The Sympathetic Division <br />Sympathetic division anatomy <br />Preganglionic neurons between segments T1 and L2 <br />Ganglionic neurons in ganglia near vertebral column <br />The preganlionic fibers are short and the postganglionic fibers are long <br />The job is to prepare the body for fight of flight responses <br />Specialized neurons in adrenal glands <br />Parasympathetic division <br />The preganlionic fibers originate in the brain stem and the sacral segments of the spinal cord <br />They synapse in ganglion which are close to the target organ <br />This means that the preganlionic fibers are long and the postganglionic fibers are short <br />Job is to conserve energy <br />This means that if you consume a heavy meals, the activity is for digestions, absorption, and waste removal <br />Figure 16.3 The Organization of the Sympathetic Division of the ANS <br />Sympathetic division <br />The division consists of preganglionic neurons that are located between segments T1 and L2 of the spinal cord <br />The cell bodies are located in the gray matter of the lateral gray horns of their axons axons enter the ventral root at three segments <br /> <br />Sympathetic chain ganglion <br />Can also be called paaravertebral ganglion or lateral ganglion <br />These are found on both sides of the vertebral column <br />Innervates body wall, inside the thoracic cavity, and head and limbs <br /> <br />Collateral ganglia <br />Prevertebral ganglia <br />Innervates tissues and organs in the abdominopelvic cavity <br /> <br /> <br />Adrenal medullae <br />The center of each adrenal gland <br />Neurotransmitters released directly into the blood stream <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Sympathetic chain ganglion <br />Preganglionic fibers that carry motor commands that target structures in the body wall, thoracic cavity, or in the head, neck, or limbs, it will synapse in one or more sympathetic chain ganglion <br />Postganglionic fibers paths will differ <br />Postganglionic fibers <br />These control effectors in the body wall, head, neck, limbs <br /> <br />Organization and anatomy of the sympathetic division <br />The T1 and L2 spinal segments contain sympathetic preganglionic fibers <br />These segments of T1-L2, ventral roots give rise to myelinated white ramus <br />Which then lead to sympathetic chain ganglia or in the adrenal medulla <br />Sympathetic chain ganglia <br />Two final routes <br />Postganglionic fibers which control visceral effectors in wall, head, neck, or limbs <br />Potganglionic fibers which innervate structures of the heart and lungs form sympathetic nerves <br /> <br /> <br />Summary <br />The cervical, inferior lumbar, and sacral chain receive preganglionic innervation by preganglionic fibers from spinal segments T1 – L2 and every spinal nerve receives a gray ramus from a ganglionic of the sympathetic chain <br />Only the thoracic and superior lumbar ganglion T1 – L2 receive preganglionic fibers from white rami <br />Every spibal nerve receives gray ramus from a ganglion of the sympathetic chain <br />Collateral Ganglia <br />Figure 16.5 The Distribution of Sympathetic Innervation <br />Postganglionic fibers <br />Rejoin spinal nerves and reach their destination by way of the dorsal and ventral rami <br />Those targeting structures in the thoracic cavity form sympathetic nerves <br />Go directly to their destination <br />Abdominopelvic viscera <br />Sympathetic innervation via preganglionic fibers synapse within collateral ganglia <br />Splanchic nerves <br />Abdominopelvic viscera <br />Celiac ganglion <br />Innervates stomach, liver, gall bladder, pancreas, spleen <br />Superior mesenteric ganglion <br />Innervates small intestine and initial portion of large intestine <br />Inferior mesenteric ganglion <br />Innervates kidney, urinary bladder, sex organs, and final portion of large intestine <br />Sympathetic activation <br />In crises, the entire sympathetic division responds <br />Sympathetic activation <br />Affects include increased alertness, energy and euphoria, increased cardiovascular and respiratory activities, elevation in muscle tone, mobilization of energy resources <br />Neurotransmitters and sympathetic function <br />Stimulation of sympathetic division has two distinct results <br />Release of ACh or NE at specific locations <br />Secretion of E and NE into general circulation <br />Most postganglionic fibers are adrenergic, a few are cholinergic or nitroxidergic <br />Two types of receptors are alpha receptors and beta receptors <br />Sympathetic ganglionic neurons end in telodendria studded with varicosities filled with neurotransmitter <br />Adrenal Medullae <br />Preganglionic fibers enter an adrenal gland and proceed to its center, which is called adrenal medulla <br />This is a sympathetic ganglion <br />Here hormones are released into the blood stream <br />Secret epinephrine and norepinephrine <br />Blood is the vehicle which carries these chemical messengers <br /> <br />Sympathetic summary of activation <br />Increased alertness <br />Feeling of energy <br />Increased cardiovascular and respiratory activity <br />Elevation of muscle tone <br />Mobilization of energy reserves, breakdown of glycogen in muscle and liver cells and the release of lipids from storage <br />Figure 16.6 Sympathetic Variosities <br />Sympathetic summary division. <br />Two sets of sympathetic chain ganglion <br />Thee collateral ganglion <br />Two adrenal medullae <br />Preganlionic fibers re short <br />Postganglionic fibers are long <br />Typical examples of divergence <br />Single neuron can control many visceral effectors <br />Preganglionic fibers release ACH <br />Post ganglionic fibers release NE <br />Works through secondary messengers <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597483264571527?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974507752205782004-09-23T14:16:00.000-07:002004-09-23T14:21:47.753-07:00Chapter 15, part 2 <br />Neural Integration I: Sensory Pathways and the Somatic Nervous System <br />SECTION 15-3 The Organization of Sensory Pathways <br />First, second, and third order neurons <br />First order neurons <br />Sensory neurons that deliver sensory information to the CNS <br />Second order neurons <br />First order neurons synapse on these in the brain or spinal cord <br />Third order neurons <br />Found in the thalamus <br />Second order neurons synapse on these <br />First order neuron <br />Delivers sensations to the CNS <br />The cell body is found in the dorsal root ganglion or the cranial root ganglion <br />Second order neuron <br />Often found in the spinal cord or the brain stem <br />If the sensation is to reach our CNS, then the information must be posted to a third order neuron <br />Third order neuron <br />Found in the thalamus <br />These synapse on sensory areas of the primary sensory cortex <br /> <br />Somatic sensory pathways: divisions <br />Three major pathways carry sensory information <br />Posterior column pathway <br />Anterolateral pathway <br />Spinocerebellar pathway <br />Figure 15.6 Sensory Pathways and Ascending Tracts in the Spinal Cord <br />Posterior column pathway <br />Carries fine touch, pressure and proprioceptive sensations <br />Axons ascend within the fasciculus gracilis and fasciculus cuneatus <br />Relay information to the thalamus via the medial lemniscus <br />Decussation occurs <br />How do we locate? <br />Our ability to determine where something is happening depends on the projection of information to the thalamus to the primary sensory cortex <br />Sensory information for head and toe arrive at different locations <br />Without this you could determine light touch but not location <br />The number of receptors is not determined by the size of the area, the face has more sensory response then the back <br />The tongue has many more receptors then the back <br />Figure 15.8 The Posterior Column Pathway and the Spinothalamic Tracts <br />Anteriorlateral pathways <br />Conscious sensations of poorly located touch, pressure, pain, and temperature <br />First order neurons enter the spinal cord synapse on second order neurons in the posterior gray horn <br />These axons cross to the opposite side of the spinal cord before ascending <br />This pathway delivers sensations to the reflex centers of the brain stem and then on to the cerebral cortex <br />The anterior spinothalamic tracts carry crude touch and pressure <br />The lateral spinothalamic tracts carry pain and temperature <br />Both of these end on third order neurons in the thalamus <br />Them relayed to primary sensory cortex regions <br />Figure 15.8 The Posterior Column Pathway and the Spinothalamic Tracts <br />Spinocerebellar pathway <br />Includes the posterior and anterior spinocerebellar tracts <br />Carries sensation to the cerebellum concerning position of muscles, tendons and joints to the cerebellum <br />Information does not reach conscious awareness <br />Axons of first order neurons synapse on interneurons of the gray horns <br />These second order neurons ascend in two tracts: posterior spinocerebellar and anterior spinocerebellar <br />Figure 15.9 The Spinocerebellar Pathway <br />Visceral sensory pathways <br />Carry information collected by interoceptors <br />Most of the information collected from cranial nerves V, VII, IX and X delivered to solitary nucleus in medulla oblongata <br />Dorsal roots of spinal nerves T1 – L2 carry visceral sensory information from organs between the diaphragm and pelvis <br />Dorsal roots of spinal nerves S2 – S4 carry sensory information below this area <br />Most information never reaches the primary sensory cortex so we generally remain unaware of these sensations <br /> <br />What kind of receptors are there? <br />Nociceptors <br />Thermorecptors <br />Tactile receptors <br />Baroreceptors <br />chemoreceptors <br />SECTION 15-4 The Somatic Nervous System <br />Objectives <br />Describe the components, processes, and functions of the somatic pathways <br />Describe the levels of information processing involved in motor control <br />Somatic Motor pathways General <br />Motor commands issued by the CNS are distributed by the somatic nervous system and the autonomic nervous system <br />The SAS controls the contractions of skeletal muscle and is under voluntary control <br />The ANS is responsible for visceral control, or involuntary control <br />Somatic motor pathways <br />Upper motor neuron <br />Cell body lies in a CNS processing center <br />Lower motor neuron <br />Cell body located in a motor nucleus of the brain or spinal cord <br />Figure 15.10 Descending (Motor) Tracts in the Spinal Cord <br />The corticospinal pathway <br />Also called the pyramidal system <br />Provides voluntary skeletal muscle control <br />This is a direct pathway upper on lower neurons <br />Also can be indirect by innervating medial and lateral pathways <br />Corticobulbar tracts terminate at cranial nerve nuclei <br />Corticospinal tracts synapse on lower motor neurons in the anterior gray horns of the spinal cord <br />Visible along medulla as pyramids <br />The three cortisospinal tracts <br />Corticobullar <br />Lateral cortiospinal <br />Anterior corticospinal <br /> <br />Corticobullar tracts <br />Synapses on lower motor neurons <br />III, IV, VI, VII, IX, XI, and XII <br />Provide conscious control over skeletal muscle that move the eye, face, jaw, neck, and pharynx <br /> <br />Corticospinal tracts <br />Synapse on lower motor neurons in gray horn of spinal cord <br />These are visible as thick bands of neurons called the pyramids <br />These tracts then cross over to the other side to enter the descending lateral corticospinal on the opposite side of the cord <br />The rest continue on the same side of anterior corticospinal tracts <br />Pyramids (review) <br />Most of the axons decussate to enter the descending lateral corticospinal tracts <br />Those that do not cross over enter the anterior corticospinal tracts <br />Provide rapid direct method for controlling skeletal muscle <br />Figure 15.11 The Corticospinal Pathway <br />The Motor homunculus <br />This is the map region of motor activities <br />The proportions of motor homunculus are different then the parts of the body they effect <br />The area is proportional to the number of motor units present in that area <br />The finer the motor control, the more motor units affected, therefore that area has a larger motor homunculus <br />The medial and lateral pathways <br />Several centers in the cerebrum, diencephalon, and brain stem issue somatic motor commands as the result of processing at the subconscious level <br />These are known as being extrapyramidal system (ESP) <br />They are better described as being: <br />The medial and lateral pathways <br />Issue motor commands as a result of subconscious processing <br />They can modify or direct muscle contractions by stimulating, facilitating or inhibiting lower motor neurons <br />What are these connections like? <br />Axons of the upper motor neurons in the lateral and medial pathways synapse on the same lower motor neurons innervated by the corticospinal pathway <br />This means that there is dual motor control, primary motor cortex and brain stem but also at the level of the lower motor neuron <br />Medial pathway <br />Its job is the primar control of gross movements of the trunk and proximal limbs <br />The upper motor neurons are located in the: <br />Receive information over the vestibular-cochlear nerve (VIII) from receptors in the inner ear that monitor position and movement of the head <br />Primary goal is to maintain posture and balance <br />The descending fibers in the spinal cord constitute the vestibulospinal tracts <br /> <br />Tectospinal tracts <br />These arise out of the colliculi <br />These receive sensory information <br />Motor axons here descend through this tract <br />They cross over before they synapse on the lower motor neurons <br /> <br />Reticulospinal tracts <br />This is a loose network which extend throughout the brain stem <br />Receives input from all ascending and descending pathways <br />It has extensive connections with the cerebrum, cerebellum and the brain stem <br />The axons of the upper motor neurons of the reticular formation descend through this pathway <br />Different areas control different areas also <br />lateral pathways <br />Lateral pathway <br />Controls muscle tone and movements of the distal muscles of the upper limbs but not as significant as those of the lateral corticospinal tracts <br />Important in maintaining motor control and muscle tone in upper limbs if the corticospinal pathways are damaged <br />They upper motor neurons lie within the red nuclei of the mesencephalon <br />This neurons cross over to the other side and descent through the rubrospinal tracts and extend only to the cervical spinal cord <br />Job of the baal nuclei and the cerebellum <br />The coordination and feedback control over muscle contractions for both conscious and subconscious activity <br />The basal nuclei <br />Responsible for the background pattern movements <br />This is especially true of rhythmic cyclic patterns movement for walking and running <br />They adjust the activity of the upper motor neurons based on the information provided by the cerebral cortex and the substantia nigra <br /> <br />Two basic nuclei exist <br />One group synapse on the thalamic neurons which send their axons to the premotor cortex association center that will direct the activity of the primary motor cortex <br />This controls the information passed on the corticospinal tract <br />The second group <br />Synapse on the reticular formation altering inhibitory or excitatory activity of the reticulospinal tract <br /> <br />What are the types of neurons that exist? <br />One the stimulates neurons by releasing Ach <br />The other inhibits neurons by releasing gamma amino butyric acid <br /> <br />Injury? <br />The primary motor cortex is responsible for fine motor control over skeletal muscles <br />Some voluntary movements can be controlled by the basal nuclei, only the movements are not as precise <br />The cerebellum <br />The cerebellum monitors proprioceptive, visual, vestibular sensory information <br />Axons relaying proprioceptive information reach the cerebellar cortex in the spinocebellar tracts <br />Visual is relayed from the superior colliculi <br />Balance information is relayed from the vestibullar nuclei <br />The net result is affecting the upper motor neuron activity of the corticospinal, medial and lateral pathways <br />More <br />All motor pathways send information to the cerebellum where the motor commands are issued <br />Movement then proceeds and is monitored by the cerebellum <br />The cerebellum adjusts movements based upon proprioceptive and vestibular information received <br />It is the job of the cerebellum to refine the cerebellar decision to move with the appropriate number of muscle units <br />The basal nuclei and cerebellum in review <br />Basal nuclei adjust motor commands issued in other processing centers <br />Provide background patterns of movement involved in voluntary motor movements <br />Cerebellum monitors proprioceptive information, visual information and vestibular sensations <br />Levels of processing and motor control activity <br />Always remember that these are a series of pathways involving synapses <br />Many activities are performed without you thinking about doing them <br />This is all a process may not involve evaluation by the cerebral cortex <br />Basic functions in the medulla and become more complex in the cerebral cortex at the primary motor center <br />control and responses <br />Levels of processing and motor control <br />Spinal and cranial reflexes provide rapid, involuntary, preprogrammed responses are the first to appear and are directed by the brain stem and mesencephalon in infants <br />Voluntary responses, learned behaviors are <br />More complex appear later and require more time to prepare and execute <br />Figure 15.12 Centers of Somatic Motor Control <br />During development( review) <br />Spinal and cranial reflexes are first to appear in infants <br />Complex reflexes develop as CNS matures and brain grows and more connections are made <br />More connections are made until age four <br />The pathways that develop will have long term affects on metal capabilities <br />You should now be familiar with: <br />The components of the afferent and efferent divisions of the nervous system, and what is meant by the somatic nervous system. <br />Why receptors respond to specific stimuli and how the organization of a receptor affects its sensitivity. <br />The major sensory pathways. <br />How we can distinguish among sensations that originate in different areas of the body. <br />The components, processes and functions of the somatic motor pathways. <br />The levels <br />of information processing involved in motor control. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597450775220578?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974145119615222004-09-23T14:15:00.000-07:002004-09-23T14:15:45.120-07:00Chapter 15, part 1 <br />Neural Integration I: Sensory Pathways and the Somatic Nervous System <br />Learning Objectives <br />Specify the components of the afferent and efferent divisions of the nervous system, and explain what is meant by the somatic nervous system. <br />Explain why receptors respond to specific stimuli and how the organization of a receptor affects its sensitivity. <br />Identify the major sensory pathways. <br />Learning Objectives <br />Explain how we can distinguish among sensations that originate in different areas of the body. <br />Describe the components, processes and functions of the somatic motor pathways. <br />Describe the levels of information processing involved in motor control. <br />SECTION 15-1 An Overview of Sensory Pathways and the Somatic Nervous System <br />Special senses <br />These are much more complex receptors then those of the general sense <br />The receptors are located in sense organs <br />This information is then distributed to specific regions of the cerebral cortex <br />Auditory <br />Visual <br />Etc <br /> <br />Specialized receptors <br />In these cases the receptor potential and the generator potential occur in different cells of the sensory neuron <br />Specialized receptors <br />Taste <br />Hearing <br />Equilibrium <br />Vision <br /> <br />Neural pathways <br />Afferent pathways <br />Sensory information coming from the sensory receptors through peripheral nerves to the spinal cord and on to the brain <br />Efferent pathways <br />Motor commands coming from the brain and spinal cord, through peripheral nerves to effecter organs <br />Figure 15.1 An Overview of Neural Integration <br />SECTION 15-2 Sensory Receptors and their Classification <br />What are Receptors <br />These are specialized cells or cell processes which provide your central nervous system with information about conditions inside and outside of the body <br />There is a term called general senses which is used to describe our sensitivity to: <br />Temperature <br />Pain <br />Touch <br />Vibration <br />Pressure <br />Proprioception <br />Sensory Receptors <br />The goal of a sensory receptor is to collect information and detail it in an action potential for transduction to the central nervous system <br />This is a graded response, the stronger the potential, the stronger the signal sent to the CNS <br />However, the receptor potential must be strong enough to generate a action potential <br /> <br />The detection of stimuli <br />The key here is that the receptors are specific for their job <br />This is a form of division of labor <br />A touch receptor would not respond strongly to a chemical stimuli <br />This is called receptor specificity <br />The area which is monitored is called the receptive field <br /> <br />What is the receptive field? <br />Some areas have many receptors and therefore the field is monitored better <br />If there are fewer receptors, the monitoring is poorer <br />Regardless of the receptor, information must be sent to the CNS <br /> <br />Sensory receptor <br />Specialized cell or cell process that monitors specific conditions <br />Arriving information is a sensation <br />Awareness of a sensation is a perception <br />How is specificity determined? <br />It is the structure of the receptor and its associated structures which determine how the receptor responds <br />Senses <br />General senses <br />Pain <br />Temperature <br />Physical distortion <br />Chemical detection <br />Receptors for general senses scattered throughout the body <br />Special senses <br />Located in specific sense organs <br />Structurally complex <br />Sensory receptors <br />Each receptor cell monitors a specific receptive field <br />Transduction <br />A large enough stimulus changes the receptor potential, reaching generator potential <br />The interpretation of sensory information <br />Sensory information that arrives at the CNS is routed to the appropriate location depending on the source <br />Those of touch reach the region called the primary sensory cortex <br />Those of visual, auditory, gustatory, and olfaction reach appropriate areas of the cortex <br />Receptors <br />Tonic receptors <br />Always active <br />Slow acting receptors <br />Phasic receptors <br />Provide information about the intensity and rate of change of a stimulus <br />Fast acting receptors <br />Adaptation <br />Is defined as the reduction in sensitivity in the presence of a constant stimulus <br /> <br />Fast adapting receptors <br />Thermoreceptors <br />temperature <br />Slow adapting receptors <br />Noiceptors <br />Pain <br /> <br />Central adaptation <br />This occurs from the CNS <br />Conscious awareness of the stimuli disappears <br /> <br />Peripheral adaptation <br />This reduces the amount of information which reaches the CNS <br />Information is processed at the spinal cord or brain stem and might not reach the higher centers of the brain <br />These often produce reflex motor responses that we are not aware of <br /> <br />Higher centers of control sensitivity <br />Output from higher centers can increase or decrease receptor sensitivity or facilitate transmission along a sensory pathway <br />Often involves the mesencephalon and the reticular activating system <br /> <br />General receptor classification <br />Exteroceptors: external environment <br />Proprioceptors: skeletal muscle and joints related to position <br />Interoceptors: monitors visceral organ functions <br /> <br />Detailed Classification of sensory receptors <br />Noiceptors: pain <br />Thermoreceptors: temperature <br />Mechanoreceptors: physical distortion <br />Chemorecpetors: chemical concentration <br /> <br />Differences <br />EACH receptor is unique in design <br />The difference between a somatic and a visceral receptor is location, location, location <br />A pain receptor in the gut looks like a pain receptor on the surface of the skin <br />However, the two send their information to different location <br />Proprioception is purely somatic <br />The visceral organs have fewer pain, temperature, and touch receptors <br />Only about 1 percent of the information that reaches the spinal cord or the brain stem actually reaches the CNS <br />The general senses <br />Three types of nociceptor <br />Provide information on pain as related to extremes of temperature <br />Provide information on pain as related to extremes of mechanical damage <br />Provide information on pain as related to extremes of dissolved chemicals <br />Myelinated type A fibers carry fast pain <br />Slower type C fibers carry slow pain <br />Theromreceptors <br />Free nerve endings of the dermis, skeletal muscle, liver, and hypothalamus <br />Cold receptors more common then hot <br />No structural difference <br />They are phasic receptors which send their information to the reticular formation, thalamus, and the primary sensory cortex <br /> <br />Mechanoreceptors <br />They respond when their cell membranes are distorted <br />They are often described as being mechanically regulated <br />They fall into three classes: <br />Tactile responses <br />Baroreceptors <br />Proprioceptors <br /> <br />Tactile receptors <br />Provide information for: <br />Touch: shape and texture <br />Pressure: mechanical distortion <br />Vibration: pulsating sounds <br />Touch vs pressure understanding depends on the degree of stimulation <br />Figure 15.2 Receptors and Receptive Fields <br />Thermoceptors and mechaniceptors (review) <br />Found in the dermis <br />Mechaniceptors <br />Sensitive to distortion of their membrane <br />Tactile receptors (six types) <br />Baroreceptors <br />Proprioceptors (three groups) <br />Figure 15.3 Tactile Receptors in the Skin <br />Tactile receptors of the skin <br />Fine touch and pressure receptors can provide information about the source of stimulation which can include location, size, shape, texture, and movement because of the narrow receptor fields <br />Crude touch and pressure provide poor localization because of the large receptor fields <br />Types: <br />Free nerve endings: <br />Root hair plexus: <br />Tactile discs: <br />Lamellated discs <br />Ruffini corpuscles <br />Free nerve endings <br />Sensitive to touch and pressure <br />Described as being tonic with narrow receptor fields <br />Root hair plexus <br />Monitor distortions and movements across the body <br />Sensory dendrites are stimulated and produce action potentials <br />Adapt rapidly with a narrow receptor field <br />Tactile discs <br />Required for fine touch and pressure receptors <br />Sensitive with very small receptor fields <br />Tactile Corpuscles <br />Perceive sensation of fine touch and pressure and low frequency vibration <br />Typically found in very sensitive areas of the skin <br />Lamellated corpuscles <br />Sensitive to deep pressure <br />Adapt rapidly <br />Ruffini corpuscles <br />Sensitive to pressure and distortion of the skin <br />Tonic receptors without adaption <br />Baroreceptors <br />Required for the monitoring of pressure <br />Consists of free nerve endings found in the wall of an an organ or on the elastic walls of a blood vessel <br />When there is a change in the elastic walls of a blood vessel an action potential is sent <br />They are highly adaptive <br />Major role in the monitoring of cardiac output. Adjust bllood pressure, and lung expansion <br />There are also stretch receptors in the GI tract as well <br /> <br />Proprioceptors <br />Monitors the position of joints, tendons, and ligaments and the state of muscle contraction <br />Muscle spindles <br />Golgi tendon organs <br />Receptors in joint capsules <br /> <br />Muscle spindles <br />Monitors skeletal muscle length <br />Golgi tendon organs <br />Location between the skeletal muscle and a tendon <br />Stimulated by tension in the tendon <br />Monitors external tension of a muscle <br />Goal is to prevent tearing <br />Receptors in joint capsules <br />Detect pressure, tension, and movement at the joint <br />Helps regulates your sense of body position with the inner ear <br /> <br />What is the job of chemoreceptors? <br />They are specialized neurons which can detect small changes in the concentration of specific chemicals or compounds <br />In general response only to those chemicals which are water soluble <br />Demonstrate peripheral adaptation and then central adaptation <br />What they do not do? <br />They do not send information to the primary sensory cortex <br />Information is sent to the brain stem which can then alter the respiratory and cardiovascular activities <br /> <br />What do they respond to? <br />Neurons of the respiratory center of the brain respond to the concentration of hydrogen ions in the blood, that is the blood pH and the carbon dioxide molecule in the CSF <br />Chemoreceptors <br />Chemoreceptors: location <br />Carotid bodies: internal carotid artery <br />Aortic bodies: aortic arch <br />Information from here is passed to cranial nerves IX (glossopharyngeal) and X (vagus) <br />Figure 15.4 Baroreceptors and the Regulation of Visceral Function <br />Figure 15.5 Chemoreceptors <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597414511961522?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095456138266307242004-09-17T14:22:00.000-07:002004-09-17T14:22:18.266-07:00Chapter 14, part 4 <br />The Brain and Cranial Nerves <br />Olfactory nerves (I) <br />Carry sensory information responsible for the sense of smell <br />Synapse within the olfactory bulb <br />Figure 14.21 The Olfactory Nerve <br />cranial nerves II, III, IV <br />Optic nerves (II) <br />Carry visual information from special sensory receptors in the eyes <br />Occulomotor nerves (III) <br />Primary source of innervation for 4 of the extraocular muscles <br />Trochlear nerves (IV) <br />Innervate the superior oblique muscles <br />Figure 14.23 Cranial Nerves Controlling the Extra-ocular Muscles <br />cranial nerves V, VI, VII <br />Trigeminal nerves (V) <br />Missed nerves with ophthalmic, maxillary and mandibular branches <br />Abducens nerve (VI) <br />Innervates the lateral rectus muscles <br />Facial nerves (VII) <br />Mixed nerves that control muscles of the face and scalp <br />Provide pressure sensations over the face <br />Receive taste information from the tongue <br />Figure 14.24 The Trigeminal Nerve <br />Figure 14.25 The Facial Nerve <br />cranial nerves VIII, IX <br />Vestibulocochlear nerves (VIII) <br />Vestibular branch monitors balance, position and movement <br />Cochlear branch monitors hearing <br />Glossopharyngeal nerves (IX) <br />Mixed nerves that innervate the tongue and pharynx <br />Control the action of swallowing <br />cranial nerves X <br />Vagus nerves (X) <br />Mixed nerves <br />Vital to the autonomic control of visceral function <br />Figure 14.26 The Vestibulocochlear Nerve <br />Figure 14.27 The Glossopharyngeal Nerve <br />Figure 14.28 The Vagus Nerve <br />cranial nerves XI, XII <br />Accessory nerves (XI) <br />Internal branches <br />Innervate voluntary swallowing muscles of the soft palate and pharynx <br />External branches <br />Control muscles associates with the pectoral girdle <br />Hypoglossal nerves (XII) <br />Provide voluntary motor control over tongue movement <br />Figure 14.29 The Accessory and Hypoglossal Nerve <br />SECTION 14-10Cranial Reflexes <br />Cranial reflexes <br />Involve sensory and motor fibers of cranial nerves <br />You should now be familiar with: <br />The major regions of the brain and their functions. <br />The formation, circulation and functions of the CSF. <br />The main components of the medulla oblongata, the pons, the cerebellum, the mesencephalon, the diencephalon, and the limbic system and their functions. <br />The major anatomical subdivisions of the cerebrum. <br />The motor, sensory and association areas of the cerebral cortex. <br />Representative examples of cranial reflexes. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109545613826630724?l=lmlechko.blogspot.com'/></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0