myometrium
Meaning of myometrium: The myometrium is the thick muscular wall of the uterus that contracts during labor and menstruation and gives the organ its structural strength.
Definition of myometrium
The myometrium is the thick, muscular middle layer of the uterine wall, situated between the outer serosal covering and the inner endometrial lining. It is composed of smooth muscle fibers arranged in interlacing layers that allow the uterus to contract with considerable force.
Myometrial contractions are responsible for labor during childbirth and also occur, to a lesser degree, during menstruation. The thickness and structure of the myometrium can be affected by conditions such as fibroids, which are benign growths of smooth muscle within the wall, and adenomyosis, in which endometrial-type tissue is found within the myometrium itself.
On imaging, the appearance of the myometrium is assessed alongside the endometrium and other uterine structures to evaluate for structural abnormalities affecting the uterus.
Used in a sentence
Imaging showed a fibroid embedded within the myometrium of the uterine wall.
Good to know
The myometrium is the muscular wall of the uterus, while the endometrium is its inner lining, a distinction that matters because conditions such as fibroids and adenomyosis affect the myometrium, whereas conditions such as endometrial polyps affect the endometrium.
Word origin
Where “myometrium” comes from
Formed from myo-, from Greek mys, meaning "muscle," and metrium, from Greek metra, meaning "uterus."