Menstrual Cycle

Menstrual cycle: Lining of uterus thickens and egg is released

During the follicular phase of the menstrual cycle, the lining of the uterus thickens to prepare for pregnancy. An egg becomes ready to be released inside a sac (follicle) on the surface of an ovary. During the luteal phase, the egg is released (ovulation). If the egg is fertilized by sperm, it may attach to (implant in) the lining of the uterus, and pregnancy begins. If the egg is not fertilized or does not implant, the lining of the uterus is shed as blood during the menstrual period (below), and the cycle starts over.

Menstrual cycle: Uterine lining is shed

ByHealthwise Staff

Primary Medical ReviewerSarah Marshall, MD - Family Medicine

Martin J. Gabica, MD - Family Medicine

Kathleen Romito, MD - Family Medicine

Specialist Medical ReviewerRebecca Sue Uranga, MD - Obstetrics and Gynecology

Current as ofOctober 6, 2017

Current as of: October 6, 2017

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Martin J. Gabica, MD - Family Medicine & Kathleen Romito, MD - Family Medicine & Rebecca Sue Uranga, MD - Obstetrics and Gynecology