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Lat Right; also a trial or accusation. Bract; Cowell.

rek'tum, n. the lowest part of the large intestine:--pl. REC'TA.--adj. REC'TAL.--ns. REC'TOSCOPE, a speculum for rectal examination; RECTOT'OMY, the operation for dividing a rectal stricture.--adjs. REC'TO-UR[=E]'THRAL, pertaining to the rectum and to the urethra; REC'TO-[=U]'TERINE, to the rectum and the uterus; REC'TO-VAG'INAL, to the rectum and the vagina; REC'TO-VES'ICAL, to the rectum and the bladder. [L. rectus, straight.]

The third and last portion of the great intestine. It forms the continuation of the sigmoid flexuie of the colon, occupies the posterior part of the pelvis, and extends from the left side of the sacrovertebral articulation to the coccyx, before which it opens outwards by the orifice called the anus. It is cylindrical, but saccated, as it were, at its inferior portion, where it is consequently larger, and is attached to the sacrum by the mesorectum. Like the other portions of the canal it is formed of three membranes. Towards the lower extremity, some parallel and longitudinal wrinkles are observable on its inner surface: these are the Columns, Columnae carneae of the Rectum or of Morgagni, (F.) Colonnes du rectum ou de Morgagni. They are merely folds of the mucous membrane, between which is a number of Lacunae. The arteries of the rectum are numerous. They proceed from the inferior mesenteric, hypogastric, and internal pudic, and are called hemorrhoidal. The veins open, partly into the hypogastric vein, partly into the inferior mesenteric. The nerves proceed from the sciatic and hypogastric plexuses. The rectum receives the faecal matters, as they pass from the colon, which serves as a reservoir for them.

Distal portion of large intestine.

The portion of the large intestine extending from the sigmoid flexure to the anus. It passes from opposite the left sacro-iliac synchondrosis, from left to right, to about the middle of the sacrum, whence it descends in the middle line to the anus. It is partially invested by the peritoneum (see mesorectum) and has an external layer of longitudinal muscular fibers, beneath which are circular fibers (see sphincter ani internum, in table of muscles, under muscle) and an inner coat of mucous membrane united to the muscular layers by connective tissue. The mucous membrane is covered with columnar epithelium and raised into crescentic longitudinal folds. [Lat.]

n. [Latin] The terminal part of the large intestines.