uterine

The uterus, or womb, is a hollow, muscular organ in the female reproductive system. In humans it sits in the pelvic cavity between the bladder and rectum and typically measures about the size of a closed fist, though size varies with age and childbirth.

Anatomy and layers: The uterus has a fundus at the top, a central body, and a cervix at the lower end that opens into the vagina. Its wall is composed of three layers: the outer perimetrium (serosa), the thick middle myometrium of smooth muscle, and the inner endometrium, a mucosal lining that undergoes cyclical changes. The endometrium has a functional layer that thickens during the menstrual cycle and a basal layer that regenerates it after menstruation. The uterus is supported by ligaments and surrounding pelvic muscles and is oriented either anteverted or retroverted.

Function: The endometrium prepares for potential embryo implantation each cycle. If implantation occurs, the embryo rests in the endometrium and the myometrium supports the growing pregnancy and later participates in labor contractions. If fertilization does not occur, the functional endometrium sheds as menstrual blood.

Development and clinical relevance: The uterus develops from Müllerian ducts during embryogenesis. Common conditions affecting the uterus include fibroids (leiomyomas) within the myometrium, endometrial hyperplasia or cancer, adenomyosis, and uterine prolapse. Congenital anomalies such as a septate or didelphic uterus can occur. Diagnostic tools include ultrasound and MRI; treatments range from medical management to procedures like dilation and curettage, endometrial ablation, or hysterectomy, depending on the condition. The term uterine is an adjective relating to the uterus.