Anatomy of Liver - Bare Area

Study Notes

The liver is the largest gland in the body, weighing approximately 1500g (2.5% of adult body weight)
It lies mainly in the right hypochondrium and epigastrium, extending into the left hypochondrium
The liver is protected by the thoracic cage and diaphragm, with its greater part lying deep to ribs 7-11 on the right side and crossing the midline towards the left below the nipple

The liver has two surfaces: a convex diaphragmatic surface (anterosuperior) and a relatively flat or even concave visceral surface (postero-inferior)
The diaphragmatic surface is smooth and molded to the undersurface of the domes of the diaphragm, which separates it from the pleurae, lungs, pericardium, and heart
The visceral surface is related to abdominal viscera, covered with peritoneum except at the fossa for the gallbladder, porta hepatis, and IVC groove

The bare area is triangular, inferior, and on the posterior surface of the right lobe, where there is no intervening peritoneum between the liver and the diaphragm
The boundaries of the bare area are:
- Anterior: superior layer of coronary ligament
- Posterior: inferior layer of coronary ligament
- Laterally: right and left triangular ligaments

Anterior: diaphragm, right and left pleura, lower margins of both lungs, right and left costal margins, xiphoid process, and anterior abdominal wall in the subcostal angle
Posterior: diaphragm, right kidney, hepatic flexure of the colon, duodenum, gallbladder, inferior vena cava, esophagus, and fundus of the stomach

Two sagittally oriented fissures, linked centrally by the transverse porta hepatis, form the letter H on the visceral surface
The left fissure is the continuous groove formed:
- Anteriorly by the fissure for the round ligament (lig.teres)
- Posteriorly by the fissure for the ligamentum venosum
The right fissure is the continuous groove formed:
- Anteriorly by the fossa for the gallbladder
- Posteriorly by the groove for the inferior vena cava

A transverse fissure found on the posteroinferior surface between the caudate and quadrate lobes
Structures passing through the porta hepatis include:
- Right and left hepatic ducts
- Right and left branches of the hepatic artery
- Right and left branches of the portal vein

The blood vessels conveying blood to the liver are the hepatic artery (30%) and portal vein (70%)
The hepatic artery brings oxygenated blood to the liver
The portal vein brings venous blood rich in the products of digestion, which have been absorbed from the gastrointestinal tract to the liver
The hepatic veins, which are intersegmental in their distribution and function, drain parts of adjacent segments

Completely surrounded by peritoneum, except at the hilum where its margins give attachment to:
- Gastrosplenic ligament to the greater curvature of stomach (carrying the short gastric and left gastroepiploic vessels)
- Lienorenal (splenorenal) ligament to the left kidney (carrying the splenic vessels and the tail of pancreas)

Anteriorly: stomach, tail of pancreas, left colic flexure, and left kidney
Posteriorly: diaphragm, which separates it from the left pleura (left costo-diaphragmatic recess), left lung, and 9, 10, and 11 ribs
Inferiorly: left colic flexure
Medially: left kidney

Splenic artery, the largest branch of the celiac artery
Runs a tortuous course along the upper border of the pancreas
Passes within the lienorenal ligament
Divides into 4-5 terminal branches, which enter the spleen at the hilus
The lack of anastomosis of these arterial vessels within the spleen results in the formation of vascular segments of the spleen with relatively avascular planes between them, enabling subtotal splenectomy