Lecture 29: Female Reproductive Physiology

Question 1

Explain the formation and maturation of ova

Answer 1

Goes from oogonia (primordial follicle) to primary oocyte. This is halted in prophase 1 due to lack of enzymes, then later on, there is enough cAMP to continue halting it. Primary oocyte goes to secondary oocyte just hours before ovulation, where it is frozen in metaphase 2. Completes meiosis upon fertilization. Embedded into uterine wall b/c of stickiness of progesterone.

Question 2

Describe the hormonal regulation of the ovarian and uterine cycles

Answer 2

FSH and LH feed into granulosa cells and thecal cells respectively of the oocyte, this leads to production of estrogen and progesterone respectively. This results in endometrial growth. High levels of estrogen results in an LH spike and ovulation.

After ovulation, low amounts of LH maintains the ruptured antrum (corpus luteum) which secretes progesterone and estrogen to maintain the endometrial lining. Afterwards, unless it is “rescued” by human chorionic gonadotropin, this degenerates the endometrial lining is shed. estrogen and progesterone feedback to inhibit FSH/LH production to prevent ovulation. LH feeds onto luteal cells for production of progesterone and estrogen.

Question 3

Explain the endocrine function of the placenta

Answer 3

takes cholesterol from mother’s blood, turns it into progesterone. Takes DHEA from baby and converts it to estrogen, feeds these two into maternal blood

Question 4

Describe lactation

Answer 4

Prolactin leads to milk production, oxytocin leads to milk letdown

Question 5

Describe birth

Answer 5

need oxytocin receptors (due to estrogen), estrogen for uniform contraction, fetal cortisol in order to produce surfactant, oxytocin during uterine contractions, prostaglandins to soften and open cervix