Ovarian cycle

Definition

The ovarian cycle refers to the monthly series of events that occur in the ovaries, primarily involving the maturation and release of an egg, which is crucial for reproduction. This cycle consists of two main phases: the follicular phase and the luteal phase, each regulated by hormones and essential for preparing the female body for potential pregnancy.

5 Must Know Facts For Your Next Test

1. The ovarian cycle typically lasts about 28 days but can range from 21 to 35 days in different individuals.
2. During the follicular phase, rising estrogen levels stimulate uterine lining thickening in preparation for a possible pregnancy.
3. Ovulation occurs when a surge in luteinizing hormone (LH) triggers the release of a mature egg from its follicle.
4. If fertilization does not occur, the corpus luteum degenerates at the end of the luteal phase, leading to a decrease in hormone levels and menstruation.
5. The ovarian cycle is closely linked to the menstrual cycle and influences other reproductive processes in females.

Review Questions

• How do hormonal changes regulate the different phases of the ovarian cycle?
  • Hormonal changes play a crucial role in regulating the ovarian cycle. During the follicular phase, follicle-stimulating hormone (FSH) promotes the growth of ovarian follicles, leading to increased estrogen production. This surge in estrogen triggers a peak in luteinizing hormone (LH), causing ovulation. In the luteal phase, after ovulation, progesterone produced by the corpus luteum helps maintain the uterine lining, preparing it for potential implantation of a fertilized egg.
• Compare and contrast the follicular phase and luteal phase in terms of hormonal influences and physiological changes.
  • The follicular phase is marked by increasing levels of FSH and estrogen, which stimulate follicle growth and prepare the uterine lining. In contrast, during the luteal phase, LH levels rise post-ovulation, leading to progesterone secretion from the corpus luteum. While the follicular phase focuses on preparing an egg for release and thickening the endometrial lining, the luteal phase emphasizes maintaining this lining to support a potential pregnancy.
• Evaluate how disruptions in the ovarian cycle can affect overall female reproductive health and fertility.
  • Disruptions in the ovarian cycle can significantly impact female reproductive health and fertility. Conditions such as polycystic ovary syndrome (PCOS) can lead to irregular cycles, affecting ovulation and hormone balance. Additionally, hormonal imbalances can hinder proper uterine lining development, reducing chances of implantation. Understanding these disruptions is essential for diagnosing infertility issues and developing appropriate treatment strategies to restore normal ovarian function and enhance reproductive potential.

Related terms

Follicular phase: The initial phase of the ovarian cycle, where follicles in the ovaries mature under the influence of follicle-stimulating hormone (FSH) and estrogen.

Ovulation:

The process during the ovarian cycle when a mature egg is released from a follicle in the ovary, typically occurring around the midpoint of the cycle.

Luteal phase: The second phase of the ovarian cycle following ovulation, characterized by the formation of the corpus luteum and production of progesterone to prepare the uterus for implantation.