Female Reproductive Physiology

1. Female Reproductive Physiology

2. Role of the human female • The female human has the following roles in reproduction • Production of the egg • Ovulation • Implantation of the egg • Pregnancy • Birth • lactation

3. Hypothalamus GnRH Anterior Pituitary LH and FSH Ovaries Estrogens / Progestins

4. ovary has three zones The functional unit of the ovaries is the single ovarian follicle

5. Thecal Cell LH cAMP Via PKA cholesterol DNA transcription pregnenolone

6. Granulosa Cell FSH • The granulosa cells do not have the enzymes to convert progesterone into androstenedione so instead must receive androstenedione from the thecal cell. cAMP Via PKA • there is an interaction between the thecal and granulosa cells in order to produce estrogens. DNA transcription Enzyme • (aromatase)

7. Effects of hormones on ovaries • Ovaries are inactive without FSH and LH • ~9-12 years FSH and LH are secreted •  monthly sexual cycle beginning • During the monthly cycle • FSH and LH levels change in a regular fashion • Estradiol and Progesterone levels also change

8. During the Follicular Phaseestradiol. FSH LH LDL Cholesterol via cAMP via cAMP Pregnenolone Estradiol INTO THE BLOOD Androstenedione Granulosa Cell Thecal Cell

9. LH LH LDL Cholesterol Cholesterol via cAMP Pregnenolone Pregnenolone Progesterone Progesterone via cAMP Androstenedione Estradiol Granulosa Cell Thecal Cell INTO THE BLOOD FSH

11. Negative and Positive Feedback In females, the hypothalamic-pituitary axis is controlled by bothnegative and positive feedback, depending on the phase of the menstrual cycle

12. Progesterone prostaglandins Collagenase Breakdown of wall Hyperemia Stigma degeneration Swelling of follicle Rupture and ovulation

13. Estrogens Estrogen is the word defining the family of sex hormones that include estradiol, estriol and estrone. They are secreted in varying amounts by the ovary but all have similar effects (though different potencies). Vaginal Epithelium Trauma-resistant • Size of Reproductive organs Initiation of Breast development Estrogens (at Puberty) Epiphyseal Fusion Histological Changes in Uterine cells

14. Further breast development • no. and activity Of ciliated cells At oviduct • Protein synthesis Estrogen(> puberty) Ovarian and Menstrual function Subcutaneous Fat deposition

15. Progestins Two hormones that come under the umbrella of progestins are released by the ovary, progesterone and 17--hydroxyprogesterone.The former is secreted in a much greater amount and it is convention to put both under the name progesterone. Alveoli cells Or breast Uterine endometrium Progesterone • ↓Uterine excitability During pregnancy Ovulation

16. Puberty and Menopause • At Puberty: • GnRH activity increases • Eventually leads to ovarian activity • Increased estrogen levels stimulate reproductive organ development. • At Menopause • Cessation of the ovarian cycle • Decreased estrogen secretion.

17. Endocrinology of Pregnancy In order to understand pregnancy you must accept the fetus, placenta and mother all as one unit. This section will discuss the hormone interactions within this unit and the reasons underlying these changes. Human Chorionic Gonadotropin It is produced by the embryo prior to implantation and after implantation is secreted by the syncytiotrophoblast cells in the intravillous space. hCG can be detected in the serum or urine 7-8 days before the expected menses and is the earliest detector of pregnancy. In fact some can now measure hCG levels 2 days after fertilization has taken place.

18. 6-12 weeks More than 12 weeks Up to 6 Weeks Corpus Luteum Placenta Progesterone Progesterone

19. The Placenta • The placenta is a specialized organ • Controls exchange between maternal and fetal blood • Capillaries from umbilical cord embed in placenta • Called placental villi • Allow for the exchange of blood. • allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply.

21. Endometrial cells Of uterus And Inhibition of myometrium. Maintains pregnancy Progesterone Cervical Plug?? Final breast development

22. Prepare body for • Parturition(myometrium) Development Of Breast Estrogens Inhibits Milk production (with progesterone) Initiator of Parturition ???

23. Growth Hormone Effects ??? On breast Decreases maternal Insulin sensitivity Human Placental Lactogen (hPL) More glucose available For fetus

24. Parturition Delivery of the fetus, occurs approximately 40 weeks after the onset of the last menstrual period. The mechanism of parturition is unclear, although roles for estrogen, progesterone,cortisol, oxytocin, prostaglandins, relaxin, and catecholamines have been proposed. Role of oxytocin Oxytocin IP3 & DAG Ca2+ Contraction Smooth muscle cell

25. Initiation of Parturition There is still much controversy and discussion over the mechanisms involved in the initiation of the birthing process. It may be due to a decrease in progesterone levels, an increase in circulating CRH or an increase in estrogen levels, or all three.

26. STRESS Posterior Pituitary oxytocin Hypothalamus oxytocin Neural reflex Placenta Uterus pgs oxytocin Contractions of uterus Fetus