Ovarian Cycle

• The ovarian cycle consists of three phases: Follicular/Proliferative Phase, Ovulation, and Luteal Phase
• In the Follicular/Proliferative Phase, the anterior pituitary gland releases FSH, stimulating the ovary to recruit five to seven ovarian follicles, with only one dominating and completing maturation
• Ovulation occurs when a mature follicle ruptures and releases the egg cell, which then travels to the fallopian tube for possible fertilization
• The Luteal Phase begins with the formation of the corpus luteum, which secretes high levels of progesterone important in the Menstrual Cycle
• The luteal phase is the latter part of the menstrual cycle, associated with higher levels of progesterone and can end in either pregnancy or luteolysis
• The ovarian cycle consists of three phases:

  • Follicular/Proliferative Phase
  • Ovulation
  • Luteal Phase
• In the Follicular/Proliferative Phase:

  • FSH (Follicle-Stimulating Hormone) is released by the anterior pituitary gland to stimulate the ovary to recruit five to seven ovarian follicles
  • Only one follicle will dominate and complete the maturation period
  • FSH induces the proliferation of granulosa cells in the developing follicles and the expression of LH receptors on these cells
  • The dominant follicle continues to mature while others undergo atresia (death)
• Ovulation:

  • A mature follicle ruptures and releases the egg cell (oocyte)
  • The egg cell travels from the ovary to the fallopian tube for possible fertilization
• The Luteal Phase:

  • Begins with the formation of the corpus luteum after the follicle ruptures
  • The corpus luteum secretes high levels of progesterone, crucial in the Menstrual Cycle
  • The luteal phase ends in either pregnancy or luteolysis, with progesterone levels significantly higher than in other phases