The mucosal lining of the cavity of the uterus is called the endometrium. It is this lining which undergoes changes over the course of the monthly menstrual cycle, sloughs off and becomes part of the menses. A biopsy of the endometrium is used to check for disease or problems of fertility.
Update Date 9/26/2015
Updated by: Daniel N. Sacks MD, FACOG, obstetrics & gynecology in private practice, West Palm Beach, FL. Review Provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.