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    Related Topics

    From Digestive System

    Head of Pancreas
    Widest part of pancreas nestled in duodenum.
    Upper Esophageal Sphincter
    Muscle ring that controls entry into the esophagus.
    Lesser Omentum
    Connects stomach and liver.
    Teeth
    Structures in the jaws for mechanical breakdown of food.
    Parotid Glands
    Largest salivary glands located near the ear.
    Common Bile Duct
    Conveys bile from liver and gallbladder to duodenum.
    Main Pancreatic Duct
    Primary duct draining pancreatic juices.
    Tail of Pancreas
    Tapered end of pancreas near spleen.
    Sublingual Glands
    Salivary glands beneath the tongue.
    Accessory Pancreatic Duct
    Secondary duct emptying into duodenum.
    Caudate Lobe
    Lobe of liver near inferior vena cava.
    Lingual Frenulum
    Fold of mucous membrane anchoring the tongue to the floor of the mouth.
    Pylorus
    Distal part of stomach leading to duodenum.
    Jejunum
    Second portion of the small intestine.
    Gingiva
    Gums; soft tissue covering the bones of the jaw.
    Sigmoid Colon
    S-shaped final segment of the colon.
    Rectum
    Straight section of the colon leading to anus.
    Falciform Ligament
    Connects liver to anterior abdominal wall.
    Oral Cavity
    Entry point of the digestive system; includes teeth, tongue, and salivary openings.
    Nasopharynx
    Superior region of pharynx behind the nasal cavity.
    Right Lobe
    Larger functional lobe of the liver.
    Lower Esophageal Sphincter
    Muscle at the junction of esophagus and stomach.
    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.
    Vermiform Appendix
    Worm-like appendage of the cecum.
    Oropharynx
    Middle region of the pharynx behind the oral cavity.

    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 stomach has a protective lining to prevent its own acid from burning through it.