Menstrual Cycle and Ovulation (Part 2) Flashcards
During days 1-10, describe the effects of FSH?
FSH stimulates follicular growth & stimulates granulosa cells to convert androstenedione to 17beta-estradiol (estrogen), increasing estrogen levels in the blood.
Increased estrogen creates a negative feedback and inhibits the production of FSH allowing the establishment of a dominant follicle.
During days 10-14, describe the effects of estrogen?
Estrogen levels create a positive feedback, driving the LH surge.
- triggers ovulation
- promotes endometrium to undergo rapid growth
What two hormones are required for estrogen production?
FSH and LH
After ovulation, LH acts on the cells of what strcutre?
corpus luteum
What produces inhibin?
Granulosa cells of follicle
-stimulated by both FSH and LH
What do inhibins do?
Inhibit FSH production
What do activins do?
Promote FSH production
What part of the menstrual cycle utilizes positive feedback?
Days 10;14: Estrogen creates LH surge
What inhibits FSH and LH in the luteal phase?
Estradiol
Progesterone
Inhibin
When do levels of estradiol, progesterone, and inhibin decrease?
End of luteal phase
-promotes GnRH to release FSH and LH
During the follicular phase, what is the major product of the follicle?
Estradiol
-needs both theca and granulosa cells
During the luteal phase, what is the major product of the corpus luteum?
Progesterone
During the menstrual cycle, when can a rise in temperature be found?
Day after ovulation
What defines the menstrual phase of the menstrual cycle?
Day 1-5 -shedding of endometrium tissue resulting in menstrual bleeding
What defines the proliferative phase of the menstrual cycle?
Day 5-14
- Proliferation of basal stromal cells and epithelial cells
- components of endometrium
- high levels of estrogen
