Erection , Lubrication, and Orgasm

1. Erection , Lubrication, and Orgasm • Where is erectile tissue located? • Once these tissues are stimulated, parasympathetic nerve impulses release nitric oxide (a vasodilator). • What effect would a vasodilator have? • If stimulation is sufficient, vestibular glands secrete mucus into the vagina. (WHY??)

2. Erection , Lubrication, and Orgasm, continued….. • The muscles of the perineum (area b/t the anus and external accessory organs) and walls of the uterus and uterine tubes contract rhythmically. • Why would all these areas need to contract? • Contractions help transport sperm to the upper ends of the uterine tubes.

3. Hormonal Control of Female Reproduction Functions • Hormones are secreted by: • Hypothalamus • Anterior pituitary gland • Ovaries • Functions: • Control development and maintenance of female secondary sex characteristics • Maturation of female sex cells • Changes during monthly reproductive cycle

4. Female Sex Hormones • About age 10, hypothalamus begins secreting GnRH, which stimulates _____________ to release _______ and _______. • Female sex hormones belong to 2 basic groups: • Estrogens (estradiol, estrone, and estriol) • Progesterone

5. Estrogens • Produced primarily in the ovaries • Stimulate enlargement of ALL accessory organs • Develop secondary sex characteristics: • Development of breasts and ductile system of mammary glands • Increased deposits of adipose tissue subcutaneously and in breasts, thighs, and buttocks • Increased vascularization of the skin

6. Progesterone • Also produced primarily in the ovaries • Promotes changes in the uterus during reproductive cycle • Affects mammary glands • Helps regulate secretion of gonadotropins from _________ gland

7. Female Reproductive Cycle • AKA, menstrual cycle • Regular, recurring changes in the uterine lining • Ovarian cycle: changes in the ovaries (occurs along with menstrual cycle) • Menarche: female’s first menstrual cycle

8. Female Reproductive Cycle, continued….. • Hypothalamus secretes ____________, which stimulates the _________ to secrete _______ and ______. • FSH stimulates maturation of an ovarian follicle. • LH stimulates ovarian cells to produce testosterone, which is used to produce estrogens.

9. Female Reproductive Cycle, continued….. • Follicular cells produce estrogens: • Maintain secondary sex characteristics • Cause uterine lining to thicken • While follicle matures (1st 14 days of cycle), the estrogens secreted INHIBIT release of LH by the anterior pituitary gland. • Once follicle is mature, LH is released.

10. Female Reproductive Cycle, continued….. • The released store of LH weakens and ruptures the bulging follicular wall, releasing the oocyte from the ovary. (What is this step called?) • The “empty follicle” fills with blood, clots, and forms a temporary glandular structure called the “corpus luteum”. • Corpus luteum secretes progesterone and estrogens.

11. Female Reproductive Cycle, continued….. • Corpus luteum secretes progesterone and estrogens: • Progesterone causes the endometrium to become more vascular and glandular. • Estrogens and progesterones inhibit release of LH and FSH from _______, so no new follicles develop while corpus luteum is active.

12. Female Reproductive Cycle, continued….. • If egg is unfertilized, corpus luteum begins to degenerate on about day 24 of cycle, becoming a “corpus albicans” • What would happen to estrogen and progesterone levels when the corpus luteum “dies”? • What do you think is the main source of estrogen and progesterone in a pregnant female?

13. Female Reproductive Cycle, continued….. • In response to decreased levels of estrogen and progesterone, blood vessels in the endometrium constrict: • No more nutrients and oxygen to thickened uterine lining • Tissues die and slough off • Blood escapes from damaged capillaries

14. Female Reproductive Cycle, continued….. • Because estrogen and progesterone levels are low, the hypothalamus and anterior pituitary glands are no longer inhibited, and cycle starts anew.