Anatomy of Liver

Liver location in abdomen

Mainly right upper quadrant, crosses midline toward left nipple

Largest gland in the body

Liver (≈1500 g, 2.5% adult body weight)

Fetal function of liver

Haemopoietic organ in mature fetus

Capsule covering liver

Glisson’s capsule

Upper border surface marking of liver

4th ICS right midclavicular → sternum/xiphoid junction → 5th ICS left midclavicular

Lateral border surface marking of liver

4th ICS right midclavicular → 5th ICS right mid-axillary → 10th rib mid-axillary

Lower border surface marking of liver

5th ICS left midclavicular → 10th rib mid-axillary along right costal margin

Two surfaces of liver

Diaphragmatic and visceral

Bare area of liver

Pressed against diaphragm, lacks visceral peritoneum

Subphrenic recess

Between diaphragm and diaphragmatic surface of liver

Visceral surface peritoneum exception

Fossa for gallbladder and porta hepatis

Porta hepatis shape

Transverse fissure forming letter H

Right sagittal fissure contents

Gallbladder fossa (anterior), IVC groove (posterior)

Left sagittal fissure contents

Round ligament fissure (anterior), ligamentum venosum fissure (posterior)

Falciform ligament content

Round ligament (ligamentum teres, umbilical vein remnant)

Ligamentum venosum origin

Remnant of fetal ductus venosus

Coronary ligaments

Peritoneal reflections from liver to diaphragm

Lesser omentum attachments

Liver to lesser curvature of stomach and first 2 cm of duodenum

Contents of lesser omentum

Portal triad (bile duct, hepatic artery, portal vein)

Subhepatic space

Supracolic compartment inferior to liver

Hepatorenal recess (Morison pouch)

Between liver and right kidney/adrenal, gravity-dependent

Communication of hepatorenal recess

Anteriorly with right subphrenic recess

Division between right and left liver

Right sagittal fissure (visceral) and Cantlie line (diaphragmatic)

Right lobe subdivisions

Medial and lateral via right portal fissure

Left lobe subdivisions

Medial and lateral via umbilical fissure

Segments of liver

Six segments (II–VIII) plus caudate lobe (Segment I)

Caudate lobe segment number

Segment I

Dual blood supply of liver

Hepatic artery (20% oxygenated), portal vein (80% nutrient-rich)

End branches of portal vein

Venous sinusoids of liver

Right hepatic duct drainage

Right lobe of liver

Left hepatic duct drainage

Left lobe, caudate lobe, quadrate lobe

Union of hepatic ducts

Forms common hepatic duct

Cystic duct joins common hepatic duct

Forms bile duct

First part of bile duct

Free margin of lesser omentum, anterior to portal vein, right of hepatic artery

Second part of bile duct

Behind first part of duodenum, right of gastroduodenal artery

Third part of bile duct

Groove on posterior surface of pancreatic head

Portal vein formation

Union of superior mesenteric vein and splenic vein at LV1 (transpyloric plane)

Portal vein position

Anterior to IVC, posterior to neck of pancreas

Portal vein division

Right and left branches at porta hepatis

Portal vein valves

Absent, allowing reverse flow in portal hypertension

Portal-systemic anastomosis sites

Esophagus, anal canal, paraumbilical region, bare retroperitoneal areas

Clinical consequence of esophageal anastomosis

Esophageal varices

Clinical consequence of anal canal anastomosis

Hemorrhoids

Clinical consequence of paraumbilical anastomosis

Caput medusae

Portal hypertension effect

Increased venous pressure, reversed flow, varices

Liver palpation in supine patient

Possible during deep inspiration due to diaphragm descent

Liver rupture risk

Large, friable, fixed organ → easily ruptured

Common site of metastatic carcinoma

Liver (direct gut drainage via portal vein)

Lymphatic drainage of liver

¼–½ lymph to thoracic duct; hepatic → celiac → cisterna chyli; phrenic → posterior mediastinal → thoracic duct

Innervation of liver

Hepatic plexus (sympathetic: celiac plexus; parasympathetic: vagal trunks)

Support of liver

Peritoneal ligaments, abdominal muscle tone, hepatic veins attached to IVC

Embryonic origin of ligamentum teres

Umbilical vein

Gravity-dependent part of peritoneal cavity

Hepatorenal recess (Morison pouch)

Artery giving rise to hepatic artery proper

Common hepatic artery

Vertebral level of portal vein formation

LV1 (transpyloric plane)

Structure into which common bile duct opens

Second part of duodenum

Structures supporting liver

Peritoneal ligaments, abdominal muscle tone, hepatic veins to IVC

Importance of surgical segments

Allows hepatic lobectomy and segmentectomy

Clinical importance of portal vein metastasis

Direct spread of gut carcinoma to liver

Weight of adult liver

≈1500 g

Percentage of adult body weight

Liver ≈2.5%

Shape of porta hepatis

Letter H on visceral surface

Round ligament other name

Ligamentum teres hepatis

Ligamentum venosum fetal origin

Ductus venosus

Portal triad components

Bile duct, hepatic artery, portal vein

Subphrenic recess sides

Right and left subphrenic recesses

Subhepatic space location

Immediately inferior to liver in supracolic compartment

Hepatorenal recess relation

Between liver and right kidney/adrenal gland

Segments supplied by tertiary portal branches

Segments II–VIII

Caudate lobe special feature

Independent venous drainage to IVC

Portal vein tributaries

Superior mesenteric vein, splenic vein

Portal vein course

Ascends in lesser omentum, posterior to bile duct and hepatic artery

Portal vein termination

Venous sinusoids of liver

Portal hypertension collateral routes

Esophagus, rectum, paraumbilical, retroperitoneal

Clinical importance of liver palpation

Detect hepatomegaly or pathology in RUQ pain

Reason liver easily ruptured

Large, friable, fixed in position

Importance of dual blood supply

Maintains function even if one source compromised

Main lymph-producing organ

Liver (¼–½ lymph to thoracic duct)

Sympathetic innervation of liver

Celiac plexus

Parasympathetic innervation of liver

Anterior and posterior vagal trunks

Fixation of liver

Peritoneal ligaments + hepatic veins to IVC

Portal vein relation to pancreas

Posterior to neck of pancreas

Portal vein relation to IVC

Anterior to IVC

Portal vein relation to bile duct

Posterior to bile duct

Portal vein relation to hepatic artery

Left of hepatic artery

Clinical importance of portal-systemic anastomoses

Collateral circulation in portal hypertension

Common bile duct relation to gastroduodenal artery

Second part lies right of gastroduodenal artery

Common bile duct relation to pancreas

Third part lies in groove on posterior surface of pancreatic head

Hepatic lobectomy basis

Segmental anatomy of liver

Segment I lobe

Caudate lobe

Segment II–VIII supply

Secondary and tertiary portal triad branches

Portal vein obstruction consequence

Blood diverted via collateral routes to IVC

Result of portal hypertension

Varices, hemorrhage, ascites

Bare area clinical importance

Site of portal-systemic anastomosis

Round ligament embryonic origin

Umbilical vein

Ligamentum venosum embryonic origin

Ductus venosus

Coronary ligament function

Anchors liver to diaphragm

Falciform ligament function

Divides liver anatomically, contains ligamentum teres

Lesser omentum surgical importance

Contains portal triad, pathway to porta hepatis

Subphrenic recess clinical importance

Site of abscess formation