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    Related Topics

    From Digestive System

    Jejunum
    Second portion of the small intestine.
    Teniae Coli
    Longitudinal muscle bands of colon.
    Ascending Colon
    Vertical segment of the colon on the right side.
    Accessory Pancreatic Duct
    Secondary duct emptying into duodenum.
    Round Ligament of Liver
    Remnant of fetal umbilical vein.
    Abdominal Cavity
    The abdominal cavity is the largest body cavity, housing vital digestive and excretory organs, lined by the peritoneum and essential for protection, metabolism, and organ movement.
    Stomach
    Muscular sac that begins digestion of protein.
    Splenic Flexure
    Bend between transverse and descending colon.
    Abdomen
    The abdomen is the body region between the chest and pelvis housing vital digestive, metabolic, and excretory organs, protected by muscular and peritoneal layers.
    Descending Colon
    Vertical segment of the colon on the left side.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Neck of Pancreas
    Short section between head and body.
    Parotid Glands
    Largest salivary glands located near the ear.
    Hard Palate
    Bony anterior portion of the roof of the mouth.
    Esophagus
    Muscular tube conveying food from the pharynx to the stomach.
    Rugae of Stomach
    Internal folds allowing expansion of the stomach.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Mesentery
    Fold of peritoneum anchoring intestines.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Duodenal Bulb
    Initial section of duodenum closest to the stomach.
    Body of Pancreas
    Central elongated portion of pancreas.
    Gallbladder
    Stores and concentrates bile.
    Duodenum
    First portion of the small intestine.
    Haustra
    Pouch-like segments of colon.

    Quadrate Lobe

    Reviewed by our medical team

    Small lobe located between gallbladder and round ligament.

    Overview

    The quadrate lobe is a small, functionally significant region of the liver that is anatomically part of the right lobe but functionally grouped with the left hepatic lobe due to its vascular and biliary connections. Despite its modest size, it lies adjacent to critical structures and contributes to hepatic and digestive function through bile production and metabolic processing.

    Location

    The quadrate lobe is located on the inferior (visceral) surface of the liver. It is bordered by:

    • Anteriorly: Inferior margin of the liver

    • Posteriorly: Porta hepatis (transverse fissure containing the hepatic vessels and ducts)

    • To the right: Fossa for the gallbladder

    • To the left: Fissure for the ligamentum teres hepatis

    It lies just beneath the contact point of the liver with the anterior abdominal wall and is visible during imaging and surgery as a rectangular region near the midline.

    Structure

    Structurally, the quadrate lobe is:

    • Part of the right anatomical lobe (based on external divisions)

    • Part of the left functional lobe (based on internal vascular segmentation)

    • Segment IVb in Couinaud’s liver segment classification

    It is composed of standard hepatic parenchyma containing:

    • Hepatocytes: Performing metabolic and detoxification functions

    • Hepatic sinusoids: Allowing nutrient-rich blood from the portal vein to interact with hepatocytes

    • Bile canaliculi: Draining bile toward the left hepatic duct

    Function

    Like other liver regions, the quadrate lobe is involved in multiple essential hepatic functions:

    • Bile production: Hepatocytes within the lobe contribute to bile synthesis, which aids in fat digestion

    • Detoxification: Processes substances absorbed from the gastrointestinal tract

    • Metabolism: Participates in carbohydrate, protein, and lipid metabolism

    • Storage: Stores glycogen, fat-soluble vitamins, and iron

    Physiological Role(s)

    Though not functionally distinct from the rest of the liver, the quadrate lobe contributes to:

    • Processing portal blood: Receives nutrient-rich blood from the portal vein (left branch)

    • Drainage of bile: Into the left hepatic duct, contributing to enterohepatic circulation

    • Support of adjacent structures: Anatomically related to the gallbladder and porta hepatis, important during hepatobiliary surgeries

    Clinical Significance

    The quadrate lobe is clinically relevant in several contexts:

    • Hepatobiliary surgery: Due to its proximity to the gallbladder, it may be affected during cholecystectomy or liver resections

    • Liver cancer and metastasis: Segment IV (which includes the quadrate lobe) may harbor primary tumors or metastases, requiring precise segmental resection

    • Portal hypertension: Involvement of nearby portal venous structures may alter blood flow to/from the quadrate lobe

    • Imaging: CT and MRI often delineate this lobe to assess lesions or anatomical variations

    • Anatomical landmarks: The quadrate lobe helps surgeons identify key landmarks like the porta hepatis and ligamentum teres during liver surgery

    Understanding the anatomy and function of the quadrate lobe is critical for hepatic segmental surgery, biliary drainage procedures, and liver imaging interpretation.

    Did you know? The pancreas helps with digestion by releasing enzymes that break down fats, proteins, and carbohydrates.