Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.

Endometrium and cervix

Female reproductive organs in pelvis, with close-up of uterus, endometrium, cervix, and vagina.

The cervix is the lower part of the uterus that opens into the vagina.

The endometrium is the mucous membrane that lines the inside of the uterus. The endometrium changes throughout the menstrual cycle. About once a month, it thickens with extra blood vessels. A pregnancy can occur if a fertilized egg attaches to, or implants in, the endometrium. If a pregnancy doesn't occur, part of the endometrium is shed, causing menstrual bleeding.

Current as of: August 2, 2022

Author: Healthwise Staff
Medical Review:
Sarah Marshall MD - Family Medicine
Martin J. Gabica MD - Family Medicine
Kathleen Romito MD - Family Medicine
JoLynn Montgomery PA - Family Medicine