(From intus, within ). The intestines, chorda, and pantices. From the pylorus to the anus is one continued canal, divided into the small and great intestines, covered by the mesentery and mesoco-jon; and, as they are longer than these membranes, they are contracted in folds to the length of the latter.

the whole length of the intestines is between seven and eight times the length of the body; the small ones arc about five of these parts. The small intestines called dertron, and cholades, because they contain bile, are named Duodenum, Jejunum, and Ileum, q. v.: the large intestines are, the Cecum, the Colon, and Rectum, q. v.

The first coat of the intestines, the external, is from the peritoneum, called ccllulosa tunica Ruyschii; tunica externa vel membranosa; the second is the muscular coat formed of two planes of muscular fibres, the one thin and longitudinal; the other thicker, in a cylindrical direction: the third is styled the nervous, but consists of cellular substance; the fourth the villous, peri-stroma. The villi are of different shapes and lengths in different parts of the intestines, more thick in the small, more long and thin in the large ones; they are thought to be secreting and absorbing organs, as there the arteries seem to terminate, and the veins to begin.

The glands of the intestines, enteradenes, are supposed to be lodged in the nervous coat, next the villous, and are divided into glandule solitaries and aggregatae; but their existence is not clearly established.

In the great intestines we may observe little holes, inflated, lead to cells analogous to the follicles of Malpighi; and by analogy we may suppose glands to exist in the great intestines near the anus, to separate a lubricating mucus, for facilitating the passage of the faeces. The arteries and veins run together on the intestines. In the intestines the first digestion is completed; from them the chyle is absorbed, and through their cavity the feces ultimately carried off. These actions are performed by their peristaltic or vermicular motion,\vhich apparently moving their contents backward or forward, in effect propel them; as the waves of an increasing tide sometimes fall short of, and at others gain on those which preceded them, but on the whole advance. This motion is caused by the successive contraction and relaxation of the circular fibres of the muscular coat; and the principal stimulus to this motion is the distention of the canal.

The action of the lungs on the diaphragm and of the abdominal muscles assist the progress of the contents of the stomach and intestines. Thus the clara lectio, reading aloud, is said by Celsus to assist digestion. Intestinalis, (from intestine, intestines). Belonging to or proceeding from the bowels. Iniestinalis arte.'ria. See Duodenalis Arteria, end Gasirica dextra arteria.

Intestina'i.is vena. See Duodenalis vena.