Final answer:
The myometrium is the muscular layer of the uterine wall, responsible for uterine contractions during labor and menstruation.
Step-by-step explanation:
The term that refers to the muscular layer of the uterine wall is the myometrium. This middle layer is composed of a thick layer of smooth muscle tissue, which is crucial for uterine contractions during labor and the expulsion of menstrual blood. The myometrium's muscle fibers are oriented in multiple directions, enabling the uterus to contract forcefully when necessary.