The uterus is an organ that is a component of a woman’s reproductive system. It’s where a fertilized egg becomes a baby. It’s also known as the womb. The uterus is pear-shaped and hollow. It’s around the size of a fist. It’s located in your lower abdomen (pelvic area). Your fallopian tubes are connected to your uterus. These tubes are used to carry eggs from your ovaries to your uterus. The cervix is the bottom section of the uterus that attaches to the vagina. The corpus or fundus refers to the upper, broader section of the uterus.

To elaborate, the uterus is divided into three layers:
1. Endometrium – This is the lining on the inside. During your menstruation, it is shed.
2. Myometrium – This is the corpus or fundus’ thick main muscle layer. This stretches to accommodate the developing baby during pregnancy. It contracts to push the baby out during childbirth.
3. Serosa – This is the outer, smooth layer. It protects the uterus and allows it to move freely in the pelvis as needed.

The stratum functionalis and stratum basalis are the two layers of the endometrium. The stratum functionalis grows and vascularizes during the menstrual cycle and is then shed off during menstruation, whereas the stratum basalis remains essentially constant. The myometrium, which is responsive to the hormone oxytocin, allows for the expansion and contraction of the uterine cavity.