=The Esophagus.=--From the pharynx the food passes to the cardiac orifice of the stomach, opposite the tenth dorsal vertebra, through the esophagus, a muscular tube about nine inches long, which collapses when empty, its lumen then appearing as a transverse slit. It, too, has three coats: 1. an inner mucous coat; 2. an areolar coat, and 3. a muscular coat, the muscles being arranged in two sets, an outer longitudinal layer and an inner circular layer. By a series of rhythmic contractions, especially of the circular fibers, the food is pushed along, though sometimes with liquid food there is no peristaltic action of the esophagus, the pharyngeal muscles alone sending it to the stomach. At the lower end of the esophagus an especially strong band of circular muscle fibers form a sort of sphincter, which prevents the regurgitation of food. The whole act of swallowing is a reflex, not a voluntary act and is due to irritation set up by the stimulus of the foreign body, the food. _Stricture of the esophagus_ is common and may be of three kinds: 1. spasmodic, occurring in nervous women; 2. fibrous, due to scar tissue, or 3. malignant, due to cancer. =The Stomach.=--The stomach is a pear-shaped dilatation of the alimentary canal, lying under the liver and diaphragm in the epigastrium and left hypochondrium and connecting the esophagus with the small intestine. It lies largely behind the ribs, but the greater curvature is only two fingers’ breadth above the umbilicus and can be manipulated through the skin. The _cardiac end_, into which the esophagus enters, is the larger and points upward to the left. The lesser and lower end, known as the _pylorus_, is at the right and its opening into the small intestine is guarded by the _pyloric sphincter_. The lesser curvature is concave and on the upper surface; the greater, convex and on the under surface. The great omentum is attached to the latter. In _size_ the stomach varies more or less, that of a man generally being larger than that of a woman, but it is usually about ten inches long and four or five inches across. It has a capacity of about five pints and serves as a storehouse for food. The stomach has four _coats_: 1. a serous coat derived from the peritoneum; 2. a muscular coat of three layers with longitudinal fibers continuous with those of the esophagus, circular fibers, and oblique fibers; 3. an areolar coat, and 4. a mucous coat, which, when the stomach is empty, is thrown into longitudinal folds or _rugæ_, and whose surface is covered with glands, the _gastric glands_, for the secretion of the digestive fluids. The _arteries_ come from the celiac axis and the _nerves_ from the pneumogastric and the solar plexus.