Menstrual Cycle Physiology: Ovarian Cycle – Brief Overview
Authors: Kristin Milloy Reviewers: Emily Ryznar Andrea Kuczynski Bernard Corenblum* * MD at time of publication
Follicular Phase
Selection of dominant follicle
Luteal Phase
Ripening of corpus luteum
Corpus luteum forms following ovulation
LH supports corpus luteum function until natural atrophy or pregnancy occur
Progesterone produced
Inhibit FSH/LH release from pituitary
Atrophy of corpus luteum if embryo does not implant
FSH from pituitary stimulates granulosa cells
↑ FSH receptors
↑ sensitivity to FSH
Follicle with most FSH receptors selected
LH from pituitary ↑ androgens from theca cells
Aromatase
↑ estrogen
↑ LH receptors
↑ sensitivity to LH
Prepare for ovulation from LH surge
LH surge
Note:
• LHandFSHare required for follicular development and continued growth until ovulation
Abbreviations:
FSH: follicle stimulating hormone LH: luteal hormone
Convert androgens to estrogen
Ovulation
Release of dominant follicle
Day 1
Day 7
Day 14
Day 21
Day 28
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published September 21, 2018 on www.thecalgaryguide.com