Female Reproduction Problem TBR

[greenseeking]

Question: 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 is A. I chose D... can anyone explain why corpus luteum isn't involved in the secretion of hormones that maintain the lining?

The passage kind of says that both thecal cells and luteal cells combine to make the corpus luteum....: The blood is soon replaced with proliferating luteal cells that combine with the thecal cells of the original follicle and produce hormonal secretions necessary for maintaining the uterine wall during the remaining days of the menstrual cycle. This hormone- secreting structure is called thecorpus luteum.

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[pm1]

I did the same mistake and have the same question. Why A over D?

I'm thinking that may be because luteal cells includes both theca and granulosa cells, while A is more specific?

 

[Dasypus]

Increasing thickness during follicular stage. After ovulation, luteal stage, maintenance of thickness.

 

[sotto voce]

-There are two phases: the follicular phase and the luteal phase.

-During the follicular phase, progesterone and estrogen are secreted to thicken the lining. At this point, we're talking about a follicle (theca cells, granulosa cells, zona pellucida, primary oocyte). Note that as some point in time, the primary oocyte become a secondary oocyte; I don't the exact timing of this.

-Then we have the increase in estradiol and LH (the "luteal surge") which cases the follicle to burst, releasting the secondary oocyte. At this point, what remains is called the corpus luteum ("yellow body"). I believe the corpus luteum is primarily theca cells, since the granulosa cells and zona pellucida go with the primary oocyte.

http://faculty.stcc.edu/AandP/AP/AP2pages/reprod/oogenesi.htm
http://training.seer.cancer.gov/anatomy/reproductive/female/ovaries.html

For the order of layers, I use the mnemonic "Two Gods: Zeus and Odin" (Theca, Granulosa, Zona pellucida, Oocyte).

This is my understanding of the process. Bona fortuna.

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Oh, and to clarify the nomenclature a bit:

Primary oocyte: At birth, women have primary oocytes. These are the product of oogenesis, which occurs in the ovaries of female fetuses. These primary oocytes replicate their DNA and begin meisosis I, but this is halted in Prophase I. They remain like this until puberty.

==>Puberty: Meiosis I resumes. After division, we now have the secondary oocyte. The first polar body is produced at this point.

Secondary oocyte: A secondary oocyte begins Meisosis II, but stops at Metaphase II. Ovulation occurs. It is the secondary oocyte that is released!

==>Quasi-fertilization: Spermatazoan comes into contact with the secondary oocyte. This causes Meisosis II to continue. The result of Meisosis II is an ovum and another polar body. Note that this is NOT pregnancy.

Ovum: The result of a secondary oocyte going through Meisosis II upon contacting a spermatazoan.

==>Fertilization: Nuclei of the spermatazoan and the ovum sperm. Pregnancy still has not occurred!

Zygote: And now we have the zygote (but no pregancy yet!). Zygote to Morula to Blastula to Gastrula to Neurula. It is the Blastula that lodges in the uterus in a process known as implantation.This occurs 5-7 days after ovulation, i.e., a few days after fertilization. The woman is officially pregnant at this point.

As an aside, this means drugs that prevent implantation are "working on" (I won't use the term 'kill' so as to avoid an abortion flame war) the morula or the blastula. By definition, the morula has at least eight cells. Some people are against drugs like Plan B, since they prevent implantation. Note that this is still not an abortion, since you have not aborted the pregnancy, since the pregnancy has not begun technically. I believe the Catholic Church would like to redefine pregnancy as starting when fertilization occurs, which means using Plan B would be "getting an abortion." Just FYI, and maybe this helps you remember some of this stuff for the real test.

 

[greenseeking]

Yes but thecal cells are responsible for producing Testosterone right? shouldn't answer A have said granulosa cells of the developing follicle? For me, D still makes sense and if you see pictures in any biology book, there is still further thickening of the endometrium during the luteal phase. Thanks for your reply.

 

[sotto voce]

Yes but thecal cells are responsible for producing Testosterone right? shouldn't answer A have said granulosa cells of the developing follicle? For me, D still makes sense and if you see pictures in any biology book, there is still further thickening of the endometrium during the luteal phase. Thanks for your reply.

Eh you're right. We need a med student in here to help us out.

My gut tells me the question wanted to know what cause the initial thickening. Seems like it was a bad question.

Or maybe the nomenclature in D is wrong.

Or maybe D actually is the right answer.

 

[greenseeking]

Yea I'm really confused but thanks so much for helping me think about this problem!

 

[loveoforganic]

I really really really really really really hate female reproductive, but theca cells do produce testosterone, which is converted to estradiol by the enzyme aromatase in the granulosa cells.

What are luteal cells? I only remember theca and granulosa

 

[greenseeking]

Yeah I don't remember luteal cells either. I just kinda assumed they included all the cells involved in the "luteal phase." I think this is just a badly written question.