Longitudinal muscular layer of small intestine
Stratum musculare longitudinale intestini tenuis
- Latin synonym: Stratum longitudinale tunicae muscularis intestini tenuis; Stratum helicoideum gradus longi
- Synonym: Longitudinal layer of muscular coat of small intestine; Long pitch helicoidal layer
- Related terms: Longitudinal layer; Long pitch helicoidal layer
Definition
The muscular coat (tunica muscularis) consists of two layers of unstriped fibers: an external, longitudinal, and an internal, circular layer.
The longitudinal fibers are thinly scattered over the surface of the intestine, and are more distinct along its free border.
The circular fibers form a thick, uniform layer, and are composed of plain muscle cells of considerable length.
The muscular coat is thicker at the upper than at the lower part of the small intestine.