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    Related Topics

    From Digestive System

    Gallbladder
    Stores and concentrates bile.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Splenic Flexure
    Bend between transverse and descending colon.
    Pancreas
    Gland with both endocrine and exocrine functions.
    Ligamentum Venosum
    Remnant of ductus venosus in liver.
    Peritoneum
    Serous membrane lining the abdominal cavity.
    Sigmoid Colon
    S-shaped final segment of the colon.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Submandibular Glands
    Salivary glands beneath the mandible.
    Falciform Ligament
    Connects liver to anterior abdominal wall.
    Anal Canal
    Terminal part of the large intestine.
    Body of Pancreas
    Central elongated portion of pancreas.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Common Hepatic Duct
    Carries bile from liver to bile duct.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Mesocolon
    Peritoneal fold attaching colon to posterior wall.
    Common Bile Duct
    Conveys bile from liver and gallbladder to duodenum.
    Neck of Pancreas
    Short section between head and body.
    Lesser Omentum
    Connects stomach and liver.
    Laryngopharynx
    Lower part of pharynx leading to esophagus.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Vermiform Appendix
    Worm-like appendage of the cecum.
    Oropharynx
    Middle region of the pharynx behind the oral cavity.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Rugae of Stomach
    Internal folds allowing expansion of the stomach.

    Haustra

    Reviewed by our medical team

    Pouch-like segments of colon.

    Overview

    Haustra are small, pouch-like sacculations or bulges along the wall of the large intestine. They give the colon its segmented appearance and play an important role in segmental mixing and movement of fecal matter. Haustra are a distinctive anatomical feature of the colon and are created by the action of specialized longitudinal muscle bands known as the taeniae coli.

    Location

    Haustra are found throughout the entire colon, specifically:

    • Beginning at the cecum and extending through the ascending, transverse, descending, and sigmoid colon

    • Not present in the rectum or vermiform appendix

    They are visible externally as bulges between the taeniae coli and appear internally as crescent-shaped folds called semilunar folds.

    Structure

    Each haustrum is formed by:

    • Localized contractions of the taeniae coli: Three distinct longitudinal muscle bands that are shorter than the length of the colon, causing the colon to pucker

    • Circular muscle layer: Contracts intermittently to define the haustral borders

    • Internal mucosal folds: Known as plicae semilunares, they correspond to the external haustra and segment the colon internally

    Haustra are not permanent structures; they shift in response to intraluminal contents and motility patterns.

    Function

    Haustra perform several critical functions in the colon:

    • Segmental mixing: Facilitate the mixing of colonic contents to enhance water and electrolyte absorption

    • Slow transit: Regulate the pace of fecal movement, allowing sufficient time for fluid reabsorption

    • Storage: Temporarily hold fecal matter within each haustrum before advancing to the next

    Physiological Role(s)

    In terms of gastrointestinal physiology, haustra contribute to:

    • Colonic motility: Haustral contractions are a type of segmental motility that differ from peristalsis and occur independently in different segments

    • Fluid balance: Aid in the extraction of water and salts from feces by prolonging contact with the mucosa

    • Bacterial fermentation: Prolonged mixing allows gut flora to metabolize undigested carbohydrates, generating short-chain fatty acids and gases

    Clinical Significance

    Haustra are important in the diagnosis and pathology of various intestinal conditions:

    • Loss of haustration: A smooth, featureless colon (often called a lead pipe colon) is characteristic of chronic ulcerative colitis

    • Haustral thickening: Can be seen in conditions like ischemic colitis, infectious colitis, or diverticulitis

    • Toxic megacolon: Haustra may disappear in this life-threatening complication of severe colitis, indicating dilatation and muscle paralysis

    • Radiographic significance: Haustra are visible on contrast studies and CT scans, helping distinguish the colon from small intestine (which has valvulae conniventes)

    Understanding the normal appearance and function of haustra is essential for interpreting abdominal imaging and diagnosing large bowel pathology.

    Did you know? The human stomach contains three layers of muscle that help break down food.