Musculature and mucosa of the stomach (Latin)

Outer and inner surfaces of the gaster. The upper image shows its external features. The gaster is composed of three muscular layers. The outermost layer is the stratum musculare longitudinale and its fibers are mostly situated on the curvaturae major et minor. The middle layer is the stratum musculare circulare composed of circular muscle fibers. This layer comprises the sphincter pylori which serves to regulate the passage of digested food into the duodenum. When these two layers are removed, the innermost layer, the oblique muscle fibers become visible. This layer is responsible for the peristaltic movement that churns and breaks down food in the gaster. In the image below, the paries anterior gastris has been removed to reveal its internal features. The most prominent features seen on the tunica mucosa gastris are the plicae gastricae. The canalis gastricus runs along with the curvatura minor and is formed by the stratum musculare longitudinale. The pylorus represents the terminal part of the gaster.It is divided into two parts, the antrum pylori, which connects to the corpus gastris, and the canalis pylori, which connects to the duodenum by the ostium pyloricum.