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    Related Topics

    From Digestive System

    Epiploic Appendages
    Fat-filled pouches attached to colon.
    Falciform Ligament
    Connects liver to anterior abdominal wall.
    Anal Canal
    Terminal part of the large intestine.
    Haustra
    Pouch-like segments of colon.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Liver
    Largest gland in the body with roles in metabolism and bile production.
    Laryngopharynx
    Lower part of pharynx leading to esophagus.
    Nasopharynx
    Superior region of pharynx behind the nasal cavity.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Pancreas
    Gland with both endocrine and exocrine functions.
    Soft Palate
    Muscular posterior part of the roof of the mouth.
    Uvula
    Dangling soft tissue at the back of the soft palate.
    Anus
    Opening through which feces are expelled.
    Body of Pancreas
    Central elongated portion of pancreas.
    Transverse Colon
    Horizontal part of the colon.
    Hepatic Flexure
    Bend between ascending and transverse colon.
    Common Bile Duct
    Conveys bile from liver and gallbladder to duodenum.
    Fundus
    Upper curved portion of the stomach.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Greater Omentum
    Fatty fold of peritoneum covering intestines.
    Oral Cavity
    Entry point of the digestive system; includes teeth, tongue, and salivary openings.
    Palatine Tonsils
    Lymphatic tissues on either side of the oropharynx.
    Mesocolon
    Peritoneal fold attaching colon to posterior wall.
    Cardia
    Upper opening of the stomach.

    Gallbladder

    Reviewed by our medical team

    Stores and concentrates bile.

    Overview

    The gallbladder is a small, pear-shaped organ that stores and concentrates bile produced by the liver. It plays an essential role in the digestive process by releasing bile into the small intestine to aid in the emulsification and absorption of dietary fats. Though not essential for life, the gallbladder significantly improves the efficiency of fat digestion.

    Location

    The gallbladder is located in the right upper quadrant of the abdomen. It:

    • Sits on the inferior surface of the liver, in a depression called the gallbladder fossa

    • Lies roughly at the level of the ninth costal cartilage near the midclavicular line

    • Is in close proximity to the duodenum, transverse colon, and hepatic flexure

    The gallbladder is connected to the biliary tree via the cystic duct, which joins the common hepatic duct to form the common bile duct.

    Structure

    The gallbladder is typically about 7–10 cm long and holds about 30–50 mL of bile when fully distended. It has three main parts:

    • Fundus: The rounded, anterior portion that may project beyond the liver’s edge

    • Body: The main, central region that stores bile

    • Neck: The narrow part leading into the cystic duct; contains a spiral fold called the valve of Heister

    Histologically, the gallbladder has:

    • Mucosa: Simple columnar epithelium with microvilli, arranged in folds; lacks a muscularis mucosa and submucosa

    • Muscularis externa: Smooth muscle that contracts during bile release

    • Serosa/adventitia: Outer layer depending on which surface is covered by peritoneum

    Function

    The primary functions of the gallbladder include:

    • Storage of bile: Stores bile continuously secreted by the liver during fasting periods

    • Concentration of bile: Absorbs water and electrolytes to make bile more potent

    • Controlled release of bile: Releases bile into the duodenum via the common bile duct in response to food intake, particularly fatty meals

    Physiological Role(s)

    The gallbladder supports digestive physiology in several key ways:

    • Fat digestion: Bile released from the gallbladder emulsifies dietary fats, allowing pancreatic lipase to break them down

    • Cholecystokinin (CCK) response: The hormone CCK is secreted by the duodenum in response to fat, triggering gallbladder contraction and sphincter of Oddi relaxation

    • pH balance and waste removal: Bile helps neutralize gastric acid and eliminate bilirubin, cholesterol, and toxins

    • Biliary coordination: The gallbladder ensures bile is delivered at the right time in response to meals, enhancing nutrient absorption

    Clinical Significance

    The gallbladder is commonly affected by various disorders:

    • Cholelithiasis (gallstones): Formation of stones from bile components (cholesterol, pigment, or mixed); may be asymptomatic or cause biliary colic

    • Cholecystitis: Inflammation of the gallbladder, often due to obstructed cystic duct; presents with right upper quadrant pain, fever, and positive Murphy’s sign

    • Choledocholithiasis: Gallstones that migrate into the common bile duct; can cause jaundice, pancreatitis, or cholangitis

    • Biliary dyskinesia: Gallbladder motility disorder resulting in improper bile release and indigestion after fatty meals

    • Gallbladder cancer: Rare but aggressive; more common in patients with chronic gallstones or porcelain gallbladder

    • Cholecystectomy: Surgical removal of the gallbladder; typically performed laparoscopically and does not impair long-term digestion significantly

    Diagnostic tools include ultrasound (first-line for gallstones), HIDA scan for functional assessment, MRCP, and endoscopic ultrasound (EUS). Management ranges from conservative treatment to surgery based on symptoms and complications.

    Did you know? The gallbladder can store up to 50 mL of bile, which aids in fat digestion.