Corpus luteum

Definition

The corpus luteum is a temporary endocrine structure formed in the ovaries after ovulation, playing a crucial role in regulating hormones essential for maintaining pregnancy. Following the release of an egg from the ovary, the remaining follicular cells undergo transformation into the corpus luteum, which secretes hormones like progesterone and estrogen to support the uterine lining for potential implantation of a fertilized egg.

5 Must Know Facts For Your Next Test

1. The corpus luteum develops from the ruptured follicle after ovulation and has a lifespan of about 10-14 days if fertilization does not occur.
2. If pregnancy occurs, the corpus luteum is maintained by human chorionic gonadotropin (hCG) produced by the developing embryo, allowing it to continue hormone production.
3. The main function of the corpus luteum is to secrete progesterone, which is vital for thickening the uterine lining to facilitate embryo implantation.
4. If pregnancy does not happen, the corpus luteum degenerates into scar tissue known as the corpus albicans, leading to a decrease in hormone levels and triggering menstruation.
5. The hormonal signals from the corpus luteum are essential not just for pregnancy but also for regulating the overall menstrual cycle.

Review Questions

• How does the formation of the corpus luteum relate to ovulation and what role does it play in the menstrual cycle?
  • The formation of the corpus luteum directly follows ovulation, which is when an egg is released from a mature ovarian follicle. After ovulation, the remaining follicular cells transform into the corpus luteum. This structure is critical in regulating hormone levels during the menstrual cycle, particularly through its secretion of progesterone, which helps prepare and maintain the uterine lining for a potential pregnancy.
• Discuss the consequences of corpus luteum degeneration on menstrual cycle regulation and fertility.
  • When the corpus luteum degenerates, it leads to a significant drop in progesterone and estrogen levels, which ultimately triggers menstruation. This decline in hormones signals that no pregnancy has occurred, allowing for the shedding of the uterine lining. For fertility, this degeneration can have implications as well; insufficient hormone production can lead to difficulties with implantation in future cycles or irregular menstrual cycles due to hormonal imbalances.
• Evaluate the impact of human chorionic gonadotropin (hCG) on maintaining corpus luteum function during early pregnancy and its broader significance.
  • Human chorionic gonadotropin (hCG) is crucial for maintaining corpus luteum function during early pregnancy by preventing its degeneration. When a fertilized egg implants in the uterine lining, hCG is released and stimulates the corpus luteum to continue producing progesterone, supporting pregnancy. This hormonal interplay is significant as it ensures that proper conditions are maintained for embryonic development during those critical first weeks until the placenta takes over hormone production.

Related terms

Ovulation:

The process by which an ovary releases an egg, marking the midpoint of the menstrual cycle and triggering the formation of the corpus luteum.

Progesterone: A hormone produced by the corpus luteum that prepares the uterus for implantation and helps maintain pregnancy if fertilization occurs.

Menstrual Cycle: The regular sequence of events in which the female body prepares for potential pregnancy, involving ovarian and uterine changes including ovulation and formation of the corpus luteum.