After ovulation, the corpus luteum mainly secretes which hormone to prepare the uterus for implantation?

• A. Estrogen
• B. Follicle-stimulating hormone
• C. Growth hormone
• D. Progesterone

Answer: (D)

After ovulation, the corpus luteum primarily secretes progesterone, which plays a crucial role in preparing the uterus for a potential implantation of a fertilized egg. Progesterone is vital for transforming the endometrial lining into a nutrient-rich environment conducive to embryo development. It promotes the growth of blood vessels and glands in the uterus, ensuring that the uterine lining is thickened and adequately prepared to sustain a pregnancy if fertilization occurs.

In addition to progesterone, the corpus luteum also produces some estrogen, but the predominant hormone impacting the uterine environment post-ovulation is progesterone. This hormonal action is essential for the maintenance of the early stages of pregnancy. If pregnancy does not occur, the corpus luteum degenerates, leading to a drop in progesterone levels, which ultimately results in the shedding of the endometrial lining during menstruation.