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    Related Topics

    From Digestive System

    Esophagus
    Muscular tube conveying food from the pharynx to the stomach.
    Neck of Pancreas
    Short section between head and body.
    Body
    Main central region of the stomach.
    Rugae of Stomach
    Internal folds allowing expansion of the stomach.
    Right Lobe
    Larger functional lobe of the liver.
    Accessory Pancreatic Duct
    Secondary duct emptying into duodenum.
    Ileocecal Valve
    Controls flow from ileum to cecum.
    Tail of Pancreas
    Tapered end of pancreas near spleen.
    Common Hepatic Duct
    Carries bile from liver to bile duct.
    Laryngopharynx
    Lower part of pharynx leading to esophagus.
    Cecum
    First part of large intestine.
    Round Ligament of Liver
    Remnant of fetal umbilical vein.
    Anus
    Opening through which feces are expelled.
    Major Duodenal Papilla
    Opening for bile and pancreatic ducts into duodenum.
    Cystic Duct
    Connects gallbladder to common bile duct.
    Palatine Tonsils
    Lymphatic tissues on either side of the oropharynx.
    Lesser Omentum
    Connects stomach and liver.
    Cheeks
    Lateral walls of the oral cavity composed of muscle and fat.
    Pyloric Sphincter
    Regulates passage of chyme from stomach to duodenum.
    Liver
    Largest gland in the body with roles in metabolism and bile production.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Sublingual Glands
    Salivary glands beneath the tongue.
    Stomach
    Muscular sac that begins digestion of protein.
    Lips
    Fleshy borders of the mouth that aid in speech and food intake.
    Duodenum
    First portion of the small intestine.

    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? Your gut contains millions of neurons and is often referred to as the "second brain."