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    From Digestive System

    Head of Pancreas
    Widest part of pancreas nestled in duodenum.
    Tail of Pancreas
    Tapered end of pancreas near spleen.
    Mesentery
    Fold of peritoneum anchoring intestines.
    Minor Duodenal Papilla
    Opening for accessory pancreatic duct.
    Transverse Colon
    Horizontal part of the colon.
    Vermiform Appendix
    Worm-like appendage of the cecum.
    Common Hepatic Duct
    Carries bile from liver to bile duct.
    Nasopharynx
    Superior region of pharynx behind the nasal cavity.
    Cheeks
    Lateral walls of the oral cavity composed of muscle and fat.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Submandibular Glands
    Salivary glands beneath the mandible.
    Right Lobe
    Larger functional lobe of the liver.
    Hard Palate
    Bony anterior portion of the roof of the mouth.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Lesser Omentum
    Connects stomach and liver.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Rugae of Stomach
    Internal folds allowing expansion of the stomach.
    Pancreas
    Gland with both endocrine and exocrine functions.
    Duodenal Bulb
    Initial section of duodenum closest to the stomach.
    Epiploic Appendages
    Fat-filled pouches attached to colon.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Haustra
    Pouch-like segments of colon.
    Lingual Frenulum
    Fold of mucous membrane anchoring the tongue to the floor of the mouth.
    Common Bile Duct
    Conveys bile from liver and gallbladder to duodenum.

    Liver

    Reviewed by our medical team

    Largest gland in the body with roles in metabolism and bile production.

    Overview

    The liver is the largest internal organ and one of the most vital components of the digestive system and overall metabolism. It performs a wide range of essential functions including detoxification, nutrient metabolism, bile production, protein synthesis, and storage of vitamins and glycogen. As a highly vascular organ, it also plays a central role in filtering blood from the gastrointestinal tract.

    Location

    The liver is located in the right upper quadrant of the abdominal cavity. It:

    • Sits primarily under the right dome of the diaphragm

    • Extends across the midline into the left upper quadrant

    • Is partially protected by the rib cage (ribs 7–11)

    • Is connected to surrounding structures via peritoneal folds like the falciform ligament and lesser omentum

    The liver rests above the stomach, right kidney, and duodenum, and is anchored to the anterior abdominal wall and diaphragm.

    Structure

    The liver weighs approximately 1.4 to 1.6 kg in adults and has a wedge-shaped form. Structurally, it is divided into:

    • Two anatomical lobes: Right and left, divided by the falciform ligament

    • Four functional lobes: Right, left, caudate, and quadrate lobes (based on internal vasculature)

    • Segments: According to Couinaud’s classification, it has eight functionally independent segments, each with its own vascular inflow and biliary drainage

    Internally, the liver consists of:

    • Hepatocytes: The main liver cells, arranged in plates around central veins

    • Sinusoids: Specialized capillaries that allow direct contact between blood and hepatocytes

    • Portal triads: Comprising a branch of the portal vein, hepatic artery, and bile duct at each corner of a hepatic lobule

    Function

    The liver has numerous essential functions, including:

    • Bile production: Secretes bile for emulsification and absorption of dietary fats

    • Carbohydrate metabolism: Stores glycogen and regulates blood glucose via glycogenesis and gluconeogenesis

    • Lipid metabolism: Synthesizes cholesterol, lipoproteins, and triglycerides

    • Protein synthesis: Produces essential plasma proteins such as albumin, fibrinogen, and clotting factors

    • Detoxification: Metabolizes drugs, alcohol, and toxins for excretion

    • Vitamin and mineral storage: Stores fat-soluble vitamins (A, D, E, K) and minerals (iron and copper)

    Physiological Role(s)

    In addition to its digestive functions, the liver plays major roles in:

    • Immune regulation: Contains Kupffer cells that remove bacteria and debris from portal blood

    • Hormonal metabolism: Modifies and inactivates hormones such as insulin, cortisol, and thyroid hormones

    • Blood reservoir: Stores a significant volume of blood and contributes to hemodynamic stability

    • Hemostasis: Produces clotting factors and anticoagulants necessary for blood coagulation

    Its dual blood supply (from the portal vein and hepatic artery) ensures efficient filtration and metabolic processing of nutrients from the gastrointestinal tract.

    Clinical Significance

    The liver is central to many medical conditions, both acute and chronic:

    • Hepatitis: Inflammation of the liver due to viral infection (Hepatitis A, B, C), alcohol, or autoimmune causes

    • Cirrhosis: Chronic liver damage leading to fibrosis and loss of liver function; common in alcohol abuse and chronic hepatitis

    • Fatty liver disease: Accumulation of fat within hepatocytes; can be non-alcoholic (NAFLD) or alcohol-related

    • Liver cancer: Includes hepatocellular carcinoma (HCC) and metastatic lesions from other organs

    • Jaundice: Yellowing of the skin and eyes due to impaired bilirubin metabolism

    • Portal hypertension: Increased pressure in the portal vein due to cirrhosis, leading to varices, ascites, and splenomegaly

    • Liver transplantation: Performed for end-stage liver disease and certain cancers; requires knowledge of segmental anatomy

    Liver function is evaluated using blood tests (LFTs), imaging (ultrasound, CT, MRI), and sometimes biopsy. It is a vital organ with remarkable regenerative capacity, capable of restoring function after partial resection or injury.

    Did you know? Food can be completely digested within 6 hours in the stomach and intestines.