Question 21

Estrogen initiates the preparation of the endometrium of the uterus for pregnancy.

Estrogen plays a critical role in preparing the endometrium, or uterine lining, for potential implantation of a fertilized egg. It promotes the thickening and vascularization of the endometrium, creating a suitable environment for pregnancy.

A) FSH

Follicle-stimulating hormone (FSH) is primarily involved in the maturation of ovarian follicles and the regulation of the menstrual cycle. While it indirectly supports estrogen production, it does not directly prepare the endometrium for pregnancy.

B) Estrogen

Estrogen is essential for the preparation of the endometrium for pregnancy. It stimulates the growth and maintenance of the uterine lining, ensuring it is ready to support a fertilized egg upon implantation. This makes it the correct answer.

C) LH

Luteinizing hormone (LH) is crucial for triggering ovulation and the formation of the corpus luteum, which produces progesterone. However, LH does not initiate the preparation of the endometrium; rather, it is involved in the later stages of the menstrual cycle.

D) Progesterone

Progesterone is important for maintaining the endometrium after it has been prepared by estrogen. It stabilizes the uterine lining and supports early pregnancy, but it does not initiate the preparation process itself.

Conclusion

Estrogen is the hormone responsible for initiating the preparation of the endometrium for pregnancy, making it the definitive correct answer. Other options, while important in the reproductive process, do not play a direct role in the initial preparation of the uterine lining for implantation.