Card Set Information
What is an important factor in this cycle?
What happens at the beginning of the cycle?
After that occurs?
Beginning of cycle
After menses is complete, estrogen levels are building up
What does estrogen cause?
causes proliferation of the endometrium (glandular epithelium) when menses is finished
causing increase in height of the lining
What occurs at mid-cycle?
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?
Completes proliferation of endometrium to its maximum height and maintains this height of the endometrium
Keeps it up there
If not pregnant:
Toward end of cycle, LH goes away, which was maintaining the corpus luteum, keeping it producing progesterone
Without LH, corpus luteum dies and progesterone levels drop, causing the progesterone levels to cause menses of the endometrium
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
After the first trimester, HCG disappear but progesterone levels don’t decrease because the placenta is producing progesterone