Hormone Levels During The Menstrual Cycle

Lab Exercise 8.5.1

Hormone Levels During The Menstrual Cycle

a) WX represents the hormones, which stimulate the follicle, FSH, and YZ represents the thickening of the corpus luteum, done by LH, which produces progesterone (Y).

b) The ovarian hormones released by WX is estrogen and progesterone is released by YZ.

c) Estrogen and progesterone exert negative feedback effects.

d) See attached graph.

e) See attached graph.

f) Before ovulation the temperature slowly decreases and reaches a high point at ovulation then starts to decrease again.

g) The corpus luteum is essential for establishing and maintaining pregnancy and it secretes hormones that are responsible for the thickening of the endometrium, therefore when the corpus luteum is present the temperature will rise at ovulation and then return back to normal if the egg is not fertilized. Without a corpus luteum the temperature does not rise.

h) The endometrium is thickening at Z because the egg has been released and the body is preparing itself to become pregnant so that if the egg get fertilized the egg can attach itself, and if its not fertilized at point X the endometrium wall will shed and the menstrual period will begin.

i) W because estrogen increases the thickening of the endometrium.

j) Z because estrogen and small amounts of progesterone are produced after ovulation.

k) LH is highest at ovulation and affects estrogen the most at ovulation when its most needed and in order for the negative feedback to occur so that only one egg is released, progesterone is low because its not needed till after ovulation to restart the process.

l) i) Ovulation would occur on day X because its right in the middle of the cycle and the estrogen levels are at their highest.

ii)