PHY2011 Study Guide - Final Guide: Corpus Luteum, Corpus Albicans, Menstrual Cycle
6 Jun 2018
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• Ruptured follicle takes on new role of corpus luteum (yellow body)
• CL secretes progesterone and some estrogen
• Can persist à if oocyte is fertilized, the corpus luteum can persist for 3 months until the placenta is ready
to take over hormone production
8. Corpus Luteum degenerates
• In absence of fertilization the CL degenerates into scar tissue (corpus albicans) and endometrial sloughing
occurs
• The cycle starts again à Due to absence of fertilization, decreased levels of progesterone and estrogen (due
to degraded Corpus Luteum) stimulates the release of GnRH (from hypothalamus) and thus, LH and FSH
back to the follicular stage!
Corpus luteum à produces all the progesterone
• Granulosa and theca cells that surround follicle luteinized (change in function)
• Rapid vascularisation of luteal cells
• The CL produces progesterone (and some estrogen)
• Maintenance of the CL depends on LH and, if pregnant, hCG
• If no pregnancy, CL regresses to become Corpus albicans (white body)
Major changes in the ovary during the cycle
• Continuous cycle
The uterine cycle à Menstrual cycle
• Cyclic changes of the endometrium in
response to hormones
o Endometrial changes are co-
ordinated with the ovarian cycle
• While the ovarian cycle is driven by
hormones released by the anterior pituitary,
the uterine cycle is driven by steroid
hormones released by the ovary
(progesterone and estrogen)
• 3 phases
o Menses: Destruction of the functional zone
