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    Related Topics

    From Digestive System

    Fundus
    Upper curved portion of the stomach.
    Ligamentum Venosum
    Remnant of ductus venosus in liver.
    Splenic Flexure
    Bend between transverse and descending colon.
    Tongue
    Muscular organ aiding in taste, speech, and food manipulation.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Lower Esophageal Sphincter
    Muscle at the junction of esophagus and stomach.
    Anal Canal
    Terminal part of the large intestine.
    Left Lobe
    Smaller lobe of the liver.
    Rugae of Stomach
    Internal folds allowing expansion of the stomach.
    Lips
    Fleshy borders of the mouth that aid in speech and food intake.
    Cecum
    First part of large intestine.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Quadrate Lobe
    Small lobe located between gallbladder and round ligament.
    Transverse Colon
    Horizontal part of the colon.
    Cheeks
    Lateral walls of the oral cavity composed of muscle and fat.
    Parotid Glands
    Largest salivary glands located near the ear.
    Pyloric Sphincter
    Regulates passage of chyme from stomach to duodenum.
    Soft Palate
    Muscular posterior part of the roof of the mouth.
    Hepatic Flexure
    Bend between ascending and transverse colon.
    Palatine Tonsils
    Lymphatic tissues on either side of the oropharynx.
    Oral Cavity
    Entry point of the digestive system; includes teeth, tongue, and salivary openings.
    Esophagus
    Muscular tube conveying food from the pharynx to the stomach.
    Ileum
    Final and longest portion of the small intestine.
    Major Duodenal Papilla
    Opening for bile and pancreatic ducts into duodenum.
    Stomach
    Muscular sac that begins digestion of protein.

    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? The stomach acid is strong enough to dissolve metal, but the stomach lining protects itself from being digested!