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    Related Topics

    From Digestive System

    Ileocecal Valve
    Controls flow from ileum to cecum.
    Duodenum
    First portion of the small intestine.
    Oral Cavity
    Entry point of the digestive system; includes teeth, tongue, and salivary openings.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Left Lobe
    Smaller lobe of the liver.
    Parotid Glands
    Largest salivary glands located near the ear.
    Ileum
    Final and longest portion of the small intestine.
    Epiploic Appendages
    Fat-filled pouches attached to colon.
    Rectum
    Straight section of the colon leading to anus.
    Cheeks
    Lateral walls of the oral cavity composed of muscle and fat.
    Tongue
    Muscular organ aiding in taste, speech, and food manipulation.
    Hard Palate
    Bony anterior portion of the roof of the mouth.
    Lingual Frenulum
    Fold of mucous membrane anchoring the tongue to the floor of the mouth.
    Uvula
    Dangling soft tissue at the back of the soft palate.
    Palatine Tonsils
    Lymphatic tissues on either side of the oropharynx.
    Oropharynx
    Middle region of the pharynx behind the oral cavity.
    Hepatic Flexure
    Bend between ascending and transverse colon.
    Esophagus
    Muscular tube conveying food from the pharynx to the stomach.
    Liver
    Largest gland in the body with roles in metabolism and bile production.
    Lower Esophageal Sphincter
    Muscle at the junction of esophagus and stomach.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Quadrate Lobe
    Small lobe located between gallbladder and round ligament.
    Anus
    Opening through which feces are expelled.
    Pylorus
    Distal part of stomach leading to duodenum.
    Major Duodenal Papilla
    Opening for bile and pancreatic ducts into duodenum.

    Fundus

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    Upper curved portion of the stomach.

    Overview

    The fundus is the uppermost, dome-shaped portion of the stomach. It lies superior to the opening between the esophagus and stomach and primarily functions as a storage area for ingested food and gases. Though not directly involved in mechanical digestion, the fundus plays an essential role in gastric accommodation, acid secretion, and regulating intragastric pressure.

    Location

    The fundus is located in the left upper quadrant of the abdomen, specifically:

    • Superior to the cardia of the stomach (where the esophagus enters)

    • Just below the left dome of the diaphragm

    • Posterior to the left lobe of the liver and anterior to the spleen

    On imaging or anatomical dissection, the fundus typically contains a visible gas bubble in upright individuals.

    Structure

    The fundus shares the general histological structure of the rest of the stomach, with specific features including:

    • Mucosa: Lined with simple columnar epithelium; contains tightly packed gastric glands rich in parietal and chief cells

    • Submucosa: Composed of connective tissue, blood vessels, and nerves

    • Muscularis externa: Includes inner oblique, middle circular, and outer longitudinal muscle layers for gastric motility

    • Serosa: The outermost layer, made of visceral peritoneum

    The fundic mucosa is specialized for acid and enzyme secretion.

    Function

    The fundus performs several key digestive-related functions:

    • Storage: Temporarily stores swallowed food and liquids before they move into the body and antrum of the stomach

    • Secretion: Contains gastric glands that secrete hydrochloric acid (HCl) and pepsinogen for the breakdown of proteins

    • Gas reservoir: Collects swallowed air, which can later be released through belching

    Physiological Role(s)

    The fundus contributes to several important physiological functions in the gastrointestinal system:

    • Gastric accommodation: Smooth muscle in the fundus relaxes reflexively after food enters the stomach (receptive relaxation), allowing it to expand without increasing pressure

    • Parietal cell activity: Parietal cells in the fundic glands secrete HCl, which lowers gastric pH, activates enzymes, and helps kill ingested pathogens

    • Hormonal regulation: Contributes to secretion of hormones such as ghrelin (a hunger-stimulating hormone)

    • Initial digestion: Begins enzymatic digestion of proteins using pepsin and maintains the acidic environment needed for effective gastric function

    Clinical Significance

    Several clinical conditions and considerations are associated with the fundus:

    • Gastric fundus varices: Dilated veins in the fundus can occur due to splenic vein thrombosis or portal hypertension, increasing the risk of upper gastrointestinal bleeding

    • Fundic gland polyps: Usually benign and often associated with prolonged use of proton pump inhibitors (PPIs) or familial polyposis syndromes

    • Gastric cancer: Though less common in the fundus than in the antrum, adenocarcinoma may arise in this region and present with vague upper abdominal symptoms

    • Hiatal hernia: In some cases, the fundus herniates through the diaphragm into the thoracic cavity, potentially causing gastroesophageal reflux disease (GERD)

    • Barrett’s esophagus proximity: Fundal acid production can contribute to lower esophageal exposure in reflux conditions, increasing cancer risk

    Endoscopic evaluation and upper GI imaging (such as barium studies or CT) are commonly used to assess the fundus in cases of suspected pathology.

    Did you know? Your stomach has a protective lining to prevent its own acid from burning through it.