Chapter 28, part 4
The Reproductive System
Uterine cycle
Repeating series of changes in the endometrium
Continues from menarche to menopause
Menses
Degeneration of the endometrium
Menstruation
Proliferative phase
Restoration of the endometrium
Secretory phase
Endometrial glands enlarge and accelerate their rates of secretion
Figure 28.20 The Uterine Cycle
The vagina
Major functions
Passageway for elimination of menstrual fluids
Receives the penis during sexual intercourse
Forms the inferior portion of the birth canal
Figure 28.21 The Histology of the Vagina
External genitalia
Vulva
Vestibule
Labia minora and majora
Paraurethral glands
Clitoris
Lesser and greater vestibular glands
Figure 28.22 The Female External Genitalia
Mammary glands
Pectoral fat pad
Nipple surrounded by the areola
Function in lactation under control of reproductive hormones
Figure 28.23 The Mammary Glands
Hormones of the female reproductive cycle
Control the reproductive cycle
Coordinate the ovarian and uterine cycles
Hormones of the female reproductive cycle
Key hormones include:
FSH
Stimulates follicular development
LH
Maintains structure and secretory function of corpus luteum
Estrogens
Have multiple functions
Progesterones
Stimulate endometrial growth and secretion
Figure 28.25 The Hormonal Regulation of Ovarian Activity
Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle
Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle
SECTION 28-4 The Physiology of Sexual Intercourse
Male sexual function
Arousal
Leads to erection of the penis
Parasympathetic outflow over the pelvic nerves
Emission and ejaculation
Occur under sympathetic stimulation
Results in semen being pushed toward external urethral opening
Detumescence
Subsidence of erection
Mediated by the sympathetic nervous system
Female sexual function
Stages are comparable to those of male sexual function
Arousal causes clitoral erection
Vaginal surfaces are moistened
Parasympathetic stimulation causes engorgement of blood vessels in the nipples
SECTION 28-5 Aging and the Reproductive System
Menopause
The time that ovulation and menstruation cease
Typically around age 45-55
Accompanied by a decline in circulating estrogen and progesterone
Rise in GnRH, FSH, LH
Male climacteric
Levels of circulating testosterone begin to decline
FSH and LH levels rise
Gradual reduction in sexual activity
You should now be familiar with:
The components of the reproductive system, and their functions
The components of the male and female reproductive systems
The processes of meiosis and gametogenesis in both sexes
You should now be familiar with:
The roles played by the male reproductive tract and accessory glands in the functional maturation, nourishment, storage, and transport of spermatozoa
The anatomical, physiological, and hormonal aspects of the male and female reproductive cycles
The physiology of sexual intercourse
