Menstrual cycle L3

Question 1

What are days 1-5 called?

Answer 1

Flow: * Marked by the shedding of endometrial lining
* Triggered by a decrease in ovarian hormones (particularly progesterone) - stimulates FSH and LH from pituitary
* Corpus luteum degenerates forming corpus albicans
* Low hormone levels thought to be responsible for headaches, cramps, nausea, mood changes

Question 2

What are days 6-13 called?

Answer 2

Follicular phase:
* Lasts until ovulation
* Governed by estrogen released by developing follicle (which is stimulated by FSH)
* Endometrial lining thickens (estrogen)
* FSH decreases (negative feedback from estrogen)
* LH production increases (positive feedback by estrogen)
* Follicle matures

Question 3

What is day 14 called?

Answer 3

Ovulation: * Estrogen & LH levels peak
* Follicle erupts, ovum is released into fallopian tube
* Female’s temperature peaks (may be used as a contraceptive method or to help in
impregnation)

Question 4

What are days 15-28 called?

Answer 4

Luteal phase: * Corpus luteum develops
* Lasts until menstruation
* Governed by progesterone released by the corpus luteum (stimulated by LH)
* Further ovulation & uterine contractions are inhibited (progesterone)
* Endometrial lining continues to thicken, preparing for pregnancy (progesterone & estrogen from C.L.)
* Progesterone and estrogen inhibit LH release (-ve feedback) - corpus luteum starts to degenerate - breakdown of endometrium