An outer layer of smooth muscle surrounding a hollow or tubular organ as the bladder, esophagus, large intestine, small intestine, stomach, ureter, uterus, and vagina that often consists of an inner layer of circular fibers serving to narrow the lumen of the organ and an outer layer of longitudinal fibers serving to shorten its length[BTO].

typically smooth muscle, but there may be exceptions - in the upper esophagus, part of the externa is skeletal muscle, rather than smooth muscle.

A region of muscle in many organs in the vertebrate body, adjacent to the submucosa membrane. It is responsible for gut movement such as peristalsis.

currently this class conflates a generic layer of muscle and a specific layer found lining the digestive tract (the muscularis externa), typically composed of circular and longitudinal layers (although this varies)

muscular layer

tunica muscularis

muscularis layer

uberon

tunica externa

muscularis propria

muscularis externa

muscular coat

transverse muscular fibers

tunica muscularis

muscularis

UBERON:0006660