The Rectum
Definition
The final straight part of the large intestine (12 cm)
Situation
Begins at the end of the sigmoid colon
At the sacral promontory
Situated in front of the sacrum
Features
Dilated near its termination, called rectal ampulla.
Terminates at the level of the anorectal ring (the level of the puborectalis sling) or the dentate line
Rectum is followed by the anal canal
No tinea coli as found in the colon
Two or more lateral curvatures
Supports of the rectum
Levator ani muscles
Waldeyer's fascia
Lateral ligaments - condensation of the pelvic fascia
Rectovesical fascia of Denonvillers
Pelvic peritoneum
perineal body
Relations
Anterior : coils of small intestine in the rectovesical/rectouterine pouch, bladder, prostate, seminal vesicles and the ductus deferentes/vagina
Posterior : sacrum, coccyx and the pelvic diaphragm
Blood Supply
Superior rectal artery, the continuation of the inferior mesenteric artery
Middle rectal artery
Inferior rectal artery
median sacral artery
venous drainage through corresponding veins - anastomose with portal venous system
Applied Anatomy
Carcinoma of the rectum
Rectal Thermometer
Suppositories for administration of medications
PR : Benign Prostatic Hypertrophy
Propapse of rectum
