BR CBT 1 Bio Passage

[iAiA]

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Using Figure 1, determine which hormone(s) and structures are responsible for the increase in thickness of the endometrial lining of the uterus.

A. Estrogen, progesterone, and the thecal cells of the developing follicle
B. Estrogen and the thecal cells of the developing follicle
C. Progesterone and the luteal cells of the corpus luteum
D. Progesterone, estrogen, and the luteal cells of the corpus luteum

Answer: A is the best answer.As noted in the passage, estrogen and progesterone both stimulate the thickening of the uterine lining. This can also be seen in Figure 1: During the follicular phase, estrogen and progesterone levels both rise simultaneously with the thickening of the lining of the uterus. The thecal cells of the developing follicle are responsible for the secretion of these hormones. The best answer is A.

My question is why wouldn't D also be a good answer? Doesn't the corpus luteum secrete estrogen and progesterone which ultimately causes endometrial growth post-ovulation? I know that pre-ovulation, endometrial growth is caused by estrogen released by the maturing follicle. It seems to me like both A and D are the right answer but I also feel like I might be missing something here...any help?

 

[labqi]

Questions asking about thickening. If I recall correctly the corpus luteum is used to maintain the uterine lining and not increase the thickness. Thickness
Increase occurs during the follicular phases as estrogen is peaking. Progesterone then functions to maintain that not increase the thickening. Thus during the time the corpus luteum is present (secretory phase), progesterone is doing the maintenance with some help with estrogen (primarily inhibiting the lh,fish, gnrh). Please correct me if I am incorrect.

 

[dyspareunia]

Corpus luteum maintains the already proliferated endometrium.

 

[lexw]

In the passage it states that the corpus luteum maintains the endometrial lining

 

[iAiA]

Thanks all!