Don't ovary act
Follicular Fun
A Standing Ovulation/Menstruation
Luteal Phase
100
These two cell types surround the egg (within the ovarian follicle) and are responsible for estrogen synthesis.
What are theca and granulosa cells?
100
This factor determines which follicle will become dominant.
What is vascular supply?
-Many follicles will grow each cycle but only one can become dominant (Graafian follicle)
-dominant follicle also has more FSH receptors causing it to produce more estrogen
-Occurs a few days after menstruation
100
An increase in this hormone triggers the release of the oocyte from the follicle.
What is LH?
-LH surge is caused by an increase in estradiol concentration (changes from negative to positive feedback)
100
This hormone dominates the luteal phase.
What is progesterone?
-After ovulation the ruptured follicle closes to form the corpus luteum which produces progesterone
200
This enzyme found in the granulosa cells is responsible for converting androstenedione to estrone.
What is aromatase?
200
FSH acts on this cell during the follicular phase to increase estradiol levels.
What are granulosa cells?
200
This is the cause of menstruation.
What is the degradation of the corpus luteum (drop in progesterone level)?
-vasoconstriction of the spiral arteries
-apoptosis of the endometrial cells
-collapse and desquamation of the endometrium
200
This is progesterone's feedback effect on LH/FSH in the luteal phase.
What is negative feedback?
-Since LH/FSH must remain suppressed in pregnancy the embryo produces hCG which maintains the corpus luteum and progesterone production
300
It is at this point in the menstrual cycle that meiosis of the oocyte resumes.
What is the LH surge?
300
Proliferation of the endometrial lining is triggered by increasing levels of this hormone (follicular phase/proliferative phase)
What is estrogen?
-Growth of glands, stroma, and blood vessels
300
The pulsation of GnRH release changes in this way immediately prior to ovulation.
What is gets faster?
-As the estrogen level peaks it triggers the hypothalamus to release GnRH faster leading to LH surge
300
This hormone inhibits the proliferation of the endometrial lining.
What is progesterone?
-Instead causes numerous secretions to prepare for the embryo
-Vessels grow and coil (spiral arteries)