M01.06.017 Liver

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Learning Objectives

Identify the anatomical position and the four lobes (Right, Left, Caudate, Quadrate).
Master the ligaments and recesses, specifically the clinical significance of Morison’s Pouch.
Understand the Dual Blood Supply (Hepatic Artery vs. Portal Vein) and the Portal Triad.
Correlate liver anatomy with percutaneous biopsy and pain patterns from Glisson’s capsule.

Anatomical Position & Surfaces

The liver is the largest gland in the body, primarily located in the right hypochondrium and epigastrium. It has two distinct surfaces:

Diaphragmatic Surface: Smooth and convex. Features the “Bare Area”—a posterior region not covered by peritoneum, in direct contact with the diaphragm.
Visceral Surface: Posteroinferior and irregular. It is molded by adjacent organs (stomach, right kidney, gallbladder, and colon).

Lobes and Ligaments

The liver is divided into a large Right lobe and a smaller Left lobe, with two accessory lobes on the visceral surface.

Caudate Lobe: Superior; located between the IVC and ligamentum venosum.
Quadrate Lobe: Inferior; located between the gallbladder and ligamentum teres.
Falciform Ligament: Attaches the liver to the anterior abdominal wall; contains the ligamentum teres (remnant of the umbilical vein).
Lesser Omentum: Consists of the hepatogastric and hepatoduodenal ligaments (the latter houses the portal triad).

Hepatic Recesses (Potential Spaces)

Spaces where infection or fluid (ascites/blood) can collect:

Subphrenic Spaces: Between the diaphragm and the superior liver.
Morison’s Pouch (Hepatorenal Recess): The deepest part of the peritoneal cavity when supine. High Yield: Fluid first accumulates here in bedridden patients.

Vasculature & The Portal Triad

The liver receives a unique Dual Blood Supply:

Component	Source	Function
Hepatic Artery (25%)	Coeliac Trunk	Supplies oxygenated blood.
Portal Vein (75%)	Superior Mesenteric & Splenic vv.	Supplies nutrient-rich (and toxin-rich) blood from the GIT.

The Portal Triad (found at the edges of hepatic lobules) consists of: a branch of the Hepatic Artery, a branch of the Portal Vein, and a Bile Duct.

Clinical Relevance

Glisson’s Capsule:

The fibrous covering of the liver. While the liver parenchyma has no pain fibers, the capsule is innervated by lower intercostal nerves. Distension (from inflammation or tumor) causes sharp, localized pain.

Liver Biopsy:

Typically performed via a subcostal approach using ultrasound. If clotting is a concern, a transvenous biopsy via the internal jugular vein is used.