peräsuolta

Peräsuolta, commonly known in English as the rectum, is the final section of the large intestine. It begins at the end of the sigmoid colon, at the rectosigmoid junction, and ends at the anal canal. In adults it measures roughly 12 to 15 centimeters in length and sits within the pelvic cavity. The rectum functions as a temporary reservoir for feces and plays a key role in defecation, coordinating with the internal and external anal sphincters.

Anatomy and structure: The rectal wall contains a mucosa with small transverse folds called rectal valves (Houston’s valves) that help support fecal matter. The upper rectum shares arterial supply with the colon via the superior rectal artery, while the middle and inferior portions receive blood from the middle and inferior rectal arteries. Venous drainage follows similar routes to the portal and systemic circulations. Innervation is autonomic, with parasympathetic fibers from the pelvic splanchnic nerves and sympathetic fibers from the hypogastric plexus; somatic sensation in the anal canal is carried by the inferior rectal nerves.

Function: The rectum serves as a storage site for feces and participates in the defecation reflex. As it fills, sensory signals promote the urge to defecate, while voluntary control via the external anal sphincter allows withholding or passage of stool.

Clinical significance: The rectum is a common site for hemorrhoids and rectal cancer. Other conditions include fissures, prolapse, inflammatory diseases, and related issues in surrounding tissues. Screening with colonoscopy or flexible sigmoidoscopy is used to detect cancers and polyps. Treatments range from lifestyle changes and topical therapies for hemorrhoids to surgical resections for cancer or prolapse.

The term peräsuolta is Finnish and corresponds to the rectum in medical contexts.