-
What is an important factor in this cycle?
estrogen
-
What happens at the beginning of the cycle?
After that occurs?
- a. Beginning of cycle: menses
- b. After menses is complete, estrogen levels are building up
-
What does estrogen cause?
- i. causes proliferation of the endometrium (glandular epithelium) when menses is finished
- 1. causing increase in height of the lining
-
What occurs at mid-cycle?
a. levels start decreasing because its done it’s job because it has started the proliferation of the endometrium, but it can’t make the endometrium reach its height
-
What is progesterone's job?
- 1. Completes proliferation of endometrium to its maximum height and maintains this height of the endometrium
- a. Keeps it up there
-
If not pregnant:
- i. Toward end of cycle, LH goes away, which was maintaining the corpus luteum, keeping it producing progesterone
- 1. Without LH, corpus luteum dies and progesterone levels drop, causing the progesterone levels to cause menses of the endometrium
-
If pregnant:
- i. LH still disappears because high estrogen levels cause it to turn it off; but it has no effect because HCG maintains the corpus luteum and keeps it secreting progesterone during the first trimester
- 1. After the first trimester, HCG disappear but progesterone levels don’t decrease because the placenta is producing progesterone
-
-
|
|
