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    Related Topics

    From Digestive System

    Internal Anal Sphincter
    Involuntary muscle around anal canal.
    Major Duodenal Papilla
    Opening for bile and pancreatic ducts into duodenum.
    Duodenal Bulb
    Initial section of duodenum closest to the stomach.
    Peritoneum
    Serous membrane lining the abdominal cavity.
    Submandibular Glands
    Salivary glands beneath the mandible.
    Sigmoid Colon
    S-shaped final segment of the colon.
    Rugae of Stomach
    Internal folds allowing expansion of the stomach.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Lesser Omentum
    Connects stomach and liver.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Lingual Frenulum
    Fold of mucous membrane anchoring the tongue to the floor of the mouth.
    Descending Colon
    Vertical segment of the colon on the left side.
    Right Lobe
    Larger functional lobe of the liver.
    Body of Pancreas
    Central elongated portion of pancreas.
    Stomach
    Muscular sac that begins digestion of protein.
    Anal Canal
    Terminal part of the large intestine.
    Head of Pancreas
    Widest part of pancreas nestled in duodenum.
    Ileocecal Valve
    Controls flow from ileum to cecum.
    Greater Omentum
    Fatty fold of peritoneum covering intestines.
    Accessory Pancreatic Duct
    Secondary duct emptying into duodenum.
    Lips
    Fleshy borders of the mouth that aid in speech and food intake.
    Pyloric Sphincter
    Regulates passage of chyme from stomach to duodenum.
    Parotid Glands
    Largest salivary glands located near the ear.
    Hepatic Flexure
    Bend between ascending and transverse colon.

    Cardia

    Reviewed by our medical team

    Upper opening of the stomach.

    Overview

    The cardia is the anatomical region of the stomach that surrounds the opening where the esophagus empties its contents into the stomach. It serves as a transitional zone between the esophagus and the gastric body. While small in size, the cardia plays an important role in controlling the passage of ingested material, preventing reflux, and contributing to mucosal defense.

    Location

    The cardia is located in the upper part of the stomach, just below the esophagogastric junction. It:

    • Lies to the left of the midline in the epigastric region of the abdomen

    • Is positioned just inferior to the diaphragm

    • Is continuous superiorly with the lower end of the esophagus and inferiorly with the body of the stomach

    Structure

    The cardia contains a unique type of mucosa and smooth muscle architecture:

    • Cardiac mucosa: Lined with mucus-secreting columnar epithelium to protect against acid reflux

    • Cardiac glands: Predominantly composed of mucous cells with fewer parietal and chief cells than in the body or fundus

    • Muscularis externa: Contains the lower esophageal sphincter (LES), a physiological rather than anatomical sphincter, formed by circular smooth muscle fibers that regulate passage from the esophagus into the stomach

    Unlike other regions of the stomach, the cardia lacks well-defined rugae and does not participate significantly in enzymatic digestion.

    Function

    The cardia has several key functions:

    • Acts as an entry point: Allows food and liquids from the esophagus to enter the stomach

    • Prevents reflux: The lower esophageal sphincter helps prevent backflow of gastric contents into the esophagus

    • Mucosal protection: Secretes mucus to protect the junctional mucosa from acidic gastric contents

    Physiological Role(s)

    The cardia plays a regulatory and protective role in upper gastrointestinal physiology:

    • Pressure regulation: The LES maintains a higher pressure than the stomach to prevent reflux, especially during inspiration and increased intra-abdominal pressure

    • Transition zone: Serves as a histological and functional transition between the stratified squamous epithelium of the esophagus and the columnar epithelium of the stomach

    • Gastric accommodation: Helps initiate relaxation of the gastric wall during swallowing to allow food storage without a rise in pressure

    Clinical Significance

    The cardia is involved in several upper gastrointestinal disorders:

    • Gastroesophageal reflux disease (GERD): Incompetence of the LES allows stomach acid to enter the esophagus, causing heartburn and esophagitis

    • Barrett's esophagus: Chronic acid exposure at the cardia and lower esophagus may lead to metaplastic transformation of the epithelium, increasing the risk of esophageal adenocarcinoma

    • Hiatal hernia: Protrusion of the cardia and part of the stomach into the thoracic cavity through the esophageal hiatus weakens sphincter function

    • Cardia cancer: Tumors at the cardia may mimic both esophageal and gastric cancers and often present late due to vague symptoms such as dysphagia or weight loss

    • Achalasia: A motility disorder where the LES fails to relax, impairing food entry into the stomach and sometimes causing dilation of the esophagus

    Diagnosis of cardia-related conditions involves upper endoscopy, esophageal manometry, barium swallow studies, and pH monitoring. Treatment ranges from lifestyle changes and medications to surgical interventions like fundoplication or endoscopic therapies.

    Did you know? Your small intestine is about 20 feet long but can fit into a very small space due to its folds.