Gross Anatomy of the Liver

External Features of the Liver

• The liver has five surfaces:
  • Anterior Surface
  • Posterior Surface
  • Superior Surface
  • Inferior Surface
  • Right Surface
• Inferior Border:
  • Only well-defined border in the liver.
  • Separates anterior and inferior surfaces, and right and inferior surfaces.
  • Notches:
    • Interlobar notch for ligamentum teres hepatis.
    • Cystic notch for the fundus of the gallbladder.
  • Positioned at the level of the 9th costal cartilage on the right and the 8th on the left.
  • Murphy’s Point: Situated at the right 9th costal cartilage tip, indicates maximum tenderness during gallbladder inflammation.

Detailed Surface Descriptions

Anterior Surface

• Largest surface of the liver.
• Related to the anterior abdominal wall muscles, especially rectus abdominis.
• Falciform Ligament:
  • Attached to the entire anterior surface.
  • Landmark for anatomical division into right and left lobes.

Posterior Surface

• Triangular Bar Area:
  • Largest area not covered by peritoneum.
• Groove for Inferior Vena Cava:
  • Lodges the inferior vena cava.
• Caudate Lobe:
  • Left of the groove, bounded by the ligamentum venosum fissure.
  • Connected to the right lobe by the caudate process.

Inferior Surface

• Fossa of Gallbladder:
  • Lodges the gallbladder.
• Quadrate Lobe:
  • Bounded by the fossa for gallbladder and the ligamentum teres hepatis.

Superior Surface

• Right and left triangular ligaments, and coronary ligament visible.

Right Surface

• Related to ribs 7 to 11.
  • Divided into upper, middle, and lower thirds.
  • Relates to lung, pleura, diaphragm, and costodiaphragmatic recess.

Holding the Liver in Anatomical Position

• Inferior vena cava is key for positioning.
• Insert finger into the IVC and lift for proper anatomical alignment.
• Surfaces visible: anterior, superior, posterior, and inferior.

Lobular Division

• Anatomically divided into right (large) and left (small) lobes by falciform ligament.
• Caudate Lobe:
  • Posterior surface of the right lobe, bounded by IVC groove and ligamentum venosum fissure.
• Quadrate Lobe:
  • Inferior surface of the right lobe, related to gallbladder.

Peritoneal Relations

• Liver is intraperitoneal.
• Falciform Ligament:
  • Double layer of peritoneum.
  • Contains ligamentum teres hepatis.
• Lesser Omentum:
  • Attached around porta hepatis.
• Areas not covered by peritoneum:
  • Bare area, groove for IVC, fissures.

Blood Supply and Venous Drainage

• Hepatic Arteries and Portal Vein:
  • Only 20% blood supply from arteries, 80% from portal vein.
• Hepatic Veins:
  • Drain into the inferior vena cava.
• Celiac Trunk:
  • Supplies the liver via the common hepatic artery.

Summary of Areas Not Covered by Peritoneum

• Bare area, groove for IVC, fissure for ligamentum venosum, porta hepatis.

Key Points

• Understanding the anatomy aids in discussions and assessments related to liver functions and pathologies.

This detailed summary captures the external and internal anatomical features of the liver, its lobes, surfaces, and peritoneal relations. It is essential for medical students studying gross anatomy and for practical dissections.