The rectum (rectum) is located in the pelvic cavity on its backside and opens in the perineum anus (anus). Its length is 14-18 cm rectum consists of pelvic region, located on the Pelvic Floor - rectal ampulla (ampulla recti) anus and anal canal (canalis analis), located in the perineal area under the pelvic diaphragm. In the course of the pelvic flexure is formed by the concavity of the sacrum form - sacral flexure (flexura sacralis). Another bend is formed at the transition into the anal canal - perineal flexure (flexura perinealis).

In Fig. 173.
Muscle membrane of the rectum
1 - ampulla of the rectum;
2 - muscle lifting the anus;
3 - external anal sphincter
In Fig. 174.
Rectal mucosa
1 - transverse folds;
2 - muscle membrane;
3 - lymph follicles;
4 - mucous membrane;
5 - ampulla of the rectum;
6 - muscle lifting the anus;
7 - the internal anal sphincter;
8 - anal columns;
9 - external sphincter anus;
10 - anal sinus;
11 - hemorrhoidal zone;
12 - anal anal canal

The longitudinal muscle layer of the rectum is the continuation of the muscle strips of sigmoid colon. In the muscular layer of the lower part of bundles of rectal capsules woven-coccyx muscles (m. rectococcygeus). The individual fibers are woven into the longitudinal layer of muscle that lifts the anus (m. levator ani). Around the anus the circular muscle fibers form a bulge - an involuntary internal sphincter (sphincter) anus (m. sphincter ani internus) consisting of smooth muscle. In the subcutaneous tissue is an arbitrary external anal sphincter (m. sphincter ani externus), formed by the striated muscles.

List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)