The uterus is part of the female reproductive system. You may know it as the womb. The uterus is usually pear-shaped and about the size of a fist. It is located in your pelvic area, between your bladder and your rectum. Your uterus is connected to your fallopian tubes, which help carry the egg from your ovary into the uterus. The small opening that connects the uterus to your vagina is the cervix. The uterus consists of three layers:
Endometrium. This is the inner lining.
Myometrium. This is the middle muscle layer.
Serosa. This is the outer smooth layer.
In women who still have their periods, one ovary releases an egg into a fallopian tube each month. During this time, the endometrium becomes thicker in preparation to receive a fertilized egg. If the egg isn’t fertilized, it exits the uterus through the vagina, and your endometrial lining is shed as your menstrual period. If the egg connects with a male sperm cell, however, this fertilized egg attaches to the endometrium. The uterus protects the growing fetus during pregnancy. During labor, the myometrium, or muscular tissue, helps push the baby out through the cervix. The smooth serosa makes it easy for the uterus to move in the pelvis as needed.
The female hormones estrogen and progesterone are responsible for maintaining this healthy process. Your ovaries make most of these hormones.