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    Related Topics

    From Digestive System

    Vermiform Appendix
    Worm-like appendage of the cecum.
    Palatine Tonsils
    Lymphatic tissues on either side of the oropharynx.
    Cardia
    Upper opening of the stomach.
    Ileum
    Final and longest portion of the small intestine.
    Cystic Duct
    Connects gallbladder to common bile duct.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Round Ligament of Liver
    Remnant of fetal umbilical vein.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Falciform Ligament
    Connects liver to anterior abdominal wall.
    Tongue
    Muscular organ aiding in taste, speech, and food manipulation.
    Rectum
    Straight section of the colon leading to anus.
    Esophagus
    Muscular tube conveying food from the pharynx to the stomach.
    External Anal Sphincter
    Voluntary muscle around anus.
    Right Lobe
    Larger functional lobe of the liver.
    Quadrate Lobe
    Small lobe located between gallbladder and round ligament.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Head of Pancreas
    Widest part of pancreas nestled in duodenum.
    Anal Canal
    Terminal part of the large intestine.
    Duodenal Bulb
    Initial section of duodenum closest to the stomach.
    Ileocecal Valve
    Controls flow from ileum to cecum.
    Epiploic Appendages
    Fat-filled pouches attached to colon.
    Oral Cavity
    Entry point of the digestive system; includes teeth, tongue, and salivary openings.
    Lips
    Fleshy borders of the mouth that aid in speech and food intake.
    Pylorus
    Distal part of stomach leading to duodenum.
    Nasopharynx
    Superior region of pharynx behind the nasal cavity.

    Peritoneum

    Reviewed by our medical team

    Serous membrane lining the abdominal cavity.

    Overview

    The peritoneum is a continuous, thin, and transparent serous membrane that lines the walls of the abdominal cavity and covers most of the abdominal organs. It forms a complex, slippery surface that facilitates movement, supports organs, and serves as a conduit for blood vessels, lymphatics, and nerves. The peritoneum is divided into two main layers: the parietal peritoneum and the visceral peritoneum.

    Location

    The peritoneum resides in the abdominal and pelvic cavities. It:

    • Parietal peritoneum: Lines the internal surface of the abdominal wall

    • Visceral peritoneum: Covers the outer surfaces of most abdominal organs, including the stomach, intestines, and liver

    • Encloses the peritoneal cavity, a potential space between the two layers filled with a small amount of lubricating serous fluid

    It creates structures such as the mesentery, omentum, and ligaments that suspend and connect organs.

    Structure

    The peritoneum is made up of:

    • Mesothelium: A single layer of flat, squamous epithelial cells that secrete serous fluid

    • Underlying connective tissue: Contains blood vessels, lymphatics, and nerves

    • Two continuous layers:

      • Parietal peritoneum: Sensitive to pressure, pain, and temperature; innervated by somatic nerves

      • Visceral peritoneum: Less sensitive; innervated by autonomic nerves and sensitive to stretch or ischemia

    The peritoneal cavity is a closed sac in males and open to the external environment in females via the uterine tubes.

    Function

    The peritoneum serves several vital roles:

    • Lubrication: Secretes serous fluid to reduce friction between moving organs

    • Support: Helps maintain the position of abdominal organs

    • Pathway for neurovascular supply: Blood vessels, nerves, and lymphatics travel within peritoneal folds to reach the organs

    • Fat storage: Especially in the greater omentum, which contains abundant adipose tissue

    Physiological Role(s)

    The peritoneum plays dynamic physiological roles:

    • Immunologic function: Contains macrophages and lymphocytes that respond to infection or inflammation

    • Absorptive properties: Can absorb fluids, drugs (e.g., via peritoneal dialysis), and local inflammatory mediators

    • Barrier function: Localizes infections (e.g., in appendicitis) by forming adhesions and walls off affected areas

    • Healing response: Supports rapid tissue repair following injury or inflammation

    Clinical Significance

    The peritoneum is frequently involved in various clinical conditions:

    • Peritonitis: Inflammation of the peritoneum, usually due to infection (e.g., ruptured appendix); can be life-threatening and requires urgent treatment

    • Ascites: Accumulation of fluid in the peritoneal cavity, commonly seen in liver cirrhosis, malignancy, or heart failure

    • Peritoneal carcinomatosis: Widespread cancer spread within the peritoneum, often from gastrointestinal or ovarian cancers

    • Adhesions: Fibrous bands formed after surgery or inflammation, which can cause bowel obstruction

    • Peritoneal dialysis: A treatment for renal failure where the peritoneum acts as a semipermeable membrane for waste exchange

    • Hernias: Protrusion of abdominal contents through weak spots in the abdominal wall, often involving peritoneal sacs

    The peritoneum is visualized and assessed using imaging modalities like ultrasound, CT, and diagnostic laparoscopy, especially in abdominal emergencies or oncologic evaluations.

    Did you know? The large intestine absorbs water, and the remaining material is turned into waste for elimination.