Liver

The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism ( carbohydrates Carbohydrates Carbohydrates are one of the 3 macronutrients, along with fats and proteins, serving as a source of energy to the body. These biomolecules store energy in the form of glycogen and starch, and play a role in defining the cellular structure (e.g., cellulose). Basics of Carbohydrates, proteins, lipids Lipids Lipids are a diverse group of hydrophobic organic molecules, which include fats, oils, sterols, and waxes. Fatty Acids and Lipids, hormones Hormones Hormones are messenger molecules that are synthesized in one part of the body and move through the bloodstream to exert specific regulatory effects on another part of the body. Hormones play critical roles in coordinating cellular activities throughout the body in response to the constant changes in both the internal and external environments. Hormones: Overview), nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. The liver can be divided into 4 lobes or 8 segments. Microscopically, it is divided into hepatic lobules. Its main neurovascular bundle is found within the transverse fissure of the liver, also called the porta hepatis.

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Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Table of Contents

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Development

  • Develops from the 3rd to 8th week during embryogenesis
    • Originates from the foregut endoderm Endoderm The inner of the three germ layers of an embryo. Gastrulation and Neurulation
    • Appears as the hepatic diverticulum, which later becomes the liver and the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract
  • The falciform ligament is called the ventral mesentery during the fetal period.
  • The round ligament Round ligament A fibromuscular band that attaches to the uterus and then passes along the broad ligament, out through the inguinal ring, and into the labium majus. Uterus, Cervix, and Fallopian Tubes contains the umbilical vein during gestation, which is the main fetal blood source (see table below).

Gross Anatomy

Location

The liver is the largest gland in the body. It extends from the right to the left hypochondriac region (¾ of the liver is in the right superior quadrant).

  • Immediately adjacent to the inferior surface of the diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm → location is breath-dependent (rises during exhalation, lowers during inhalation)
  • Superior limit: height of the 5th intercostal space during exhalation
  • Inferior limit: curve of the right costal arch during inhalation 
  • Surfaces: diaphragmatic and visceral
    • Intraperitoneal except for the bare area, porta hepatis, and gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract fossa 
    • Enclosed in the Glisson capsule (external layer of fibrous connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue)
  • Weight: 1.5 kg (average)

Four lobes

  • Superficially divided by fissures and ligaments
  • Functionally determined by the left and right branches of the hepatic vein and Cantlie’s line (an imaginary line that crosses the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract fossa and inferior vena cava Inferior vena cava The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels)
  1. Right lobe: largest
  2. Left lobe: separated from the right by the falciform ligament on the diaphragmatic surface
  3. Caudate lobe: between the venous ligament and groove for the inferior vena cava Inferior vena cava The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels ( IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels)
  4. Quadrate lobe: between the round ligament Round ligament A fibromuscular band that attaches to the uterus and then passes along the broad ligament, out through the inguinal ring, and into the labium majus. Uterus, Cervix, and Fallopian Tubes and the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract fossa

Impressions of adjacent structures and organs

  • Gastric: left lobe, anterior to the esophageal impression
  • Colic: inferior margin of the right lobe (right colic flexure)
  • Duodenal: right lobe, lateral to the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract (1st segment of the duodenum)
  • Renal: center of the right lobe (superior pole of the right kidney)
  • Suprarenal: superior to the renal impression (right adrenal gland)
Porta hepatis and liver inferior view

Inferior view of the visceral surface of the liver. Note the uneven structure that results from impressions of the neighboring organs. The colic impression is caused by the colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix’s hepatic flexure; the descending portion of the duodenum forms the duodenal impression.

Image by Lecturio.

Eight segments (Couinaud classification)

  • Based on a transverse plane through the bifurcation of the main portal vein
    • Exception: Caudate lobe receives blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure from both vascular branches.
  • 8 functionally independent segments, each with its own vascular inflow, outflow, and biliary drainage 
  • Segment I is the caudate lobe and can only be seen from the posterior view.
  • Segments can be surgically resected without affecting the viability of the remaining liver.
Couinaud classification illustration

Eight hepatic segments according to the Couinaud classification system.

Image by Lecturio.

Porta hepatis

The porta hepatis (also called the hepatic portal) is a transverse fissure that separates the caudate and quadrate lobes and serves as a passageway for the following: 

  • Common hepatic bile duct (exits the liver, located anteriorly and laterally)
  • Hepatic artery proper (enters the liver, located anteriorly and medially) 
  • Hepatic portal vein (enters the liver, located posteriorly, between the duct and artery)
  • Hepatic nerve plexus (contains postganglionic sympathetic innervation from the celiac plexus and preganglionic parasympathetic innervation from the vagus nerve)
  • Lymphatic vessels of the liver
Porta hepatis hepatic portal

Inferior view of the visceral surface of the liver, featuring the hepatic portal and surrounding hepatoduodenal ligament.

Image by Lecturio.

Ligaments of the liver

Definition: Ligaments of the liver are double layers of visceral peritoneum Peritoneum The peritoneum is a serous membrane lining the abdominopelvic cavity. This lining is formed by connective tissue and originates from the mesoderm. The membrane lines both the abdominal walls (as parietal peritoneum) and all of the visceral organs (as visceral peritoneum). Peritoneum and Retroperitoneum that fix the position of the liver by attaching it to the surrounding structures.

Table: Ligaments of the liver
Coronary ligaments
(anterior and posterior)
Peritoneal reflection from the diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm to the liver
Demarcates the bare area (surface of the liver with no peritoneal covering)
Falciform ligament Peritoneal reflection from the umbilicus to the liver 
Remnant of the embryonic ventral mesentery
Its free edge contains the round ligament Round ligament A fibromuscular band that attaches to the uterus and then passes along the broad ligament, out through the inguinal ring, and into the labium majus. Uterus, Cervix, and Fallopian Tubes of the liver.
Hepatoduodenal ligament Portion of the lesser omentum
Extends from the porta hepatis to the superior part of the duodenum
contents: hepatic artery proper, portal vein, common hepatic duct
Hepatogastric ligament Extends from the liver to the lesser curvature of the stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach
contents: gastric arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries
Round ligament
(also known as ligamentum teres Ligamentum teres A cord-like remnant structure formed from the closed left fetal umbilical vein. It is located along the lower edge of the falciform ligament. Uterus, Cervix, and Fallopian Tubes)
Remnant of the intra-abdominal portion of the umbilical vein
Extends from the umbilicus to the liver on the free edge of the falciform ligament
Triangular ligaments Formed by the fusion of the anterior and posterior folds of the coronary ligament
1 left and 1 right; both extend from the liver to the diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm
Venous ligament
(also known as ligamentum venosum)
Remnant of the ductus venosus
Extends from the remnant of the intra-abdominal portion of the umbilical vein to the inferior vena cava Inferior vena cava The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels
Left fissure Impressions of the round and venous ligaments
Right fissure Impressions of the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract and the inferior caval vein

Microscopic Anatomy

Hepatic (classical) lobule

  • Small hexagonal units of the liver, measuring 1–2.5 mm each, separated by thin strands of connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue
  • Central vein: Each lobule has a vein in the center that receives mixed blood from the sinusoids (via branches from the portal vein and hepatic artery), drains into the hepatic veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins, and leaves the liver via the IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels.
  • Portal triad: cluster of vessels located at the 6 vertices of each hepatic lobule:
    • Interlobular branch of the portal vein: supplies the lobule with deoxygenated blood, rich in nutrients
    • Interlobular branch of the hepatic artery proper: supplies the lobule with oxygenated blood
    • Interlobular bile duct: drains the bile from the biliary ductules in the opposite direction of blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure
    • Additionally: lymphatic vessels and a branch of the vagus nerve
Hepatic lobule illustration

Schematic diagram of the architecture of the liver, featuring the hepatic lobule. The portal triads at the corners consist of branches of the portal vein, hepatic artery proper, and a bile duct. The branch of the portal vein carries nutrient-rich, but deoxygenated blood from the small intestine Small intestine The small intestine is the longest part of the GI tract, extending from the pyloric orifice of the stomach to the ileocecal junction. The small intestine is the major organ responsible for chemical digestion and absorption of nutrients. It is divided into 3 segments: the duodenum, the jejunum, and the ileum. Small Intestine, the branch of the hepatic artery supplies the hepatocytes with oxygenated blood. The bile duct drains bile from the hepatocytes towards larger ducts and the gall bladder.

Image by Lecturio.

Portal vein lobule

  • The portal vein lobule is a lobule viewed from a 2nd perspective, with the portal triad in the center and the central veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins at the 3 vertices
  • Shaped like a triangle
  • Functional unit for bile transport
  • Bile is drawn to the center of the triangle, into the interlobular bile duct.

Hepatic acinus

  • The hepatic acinus is a lobule viewed from a 3rd perspective, with the central veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins and portal triads at the 4 vertices.
  • Diamond-shaped
  • Functional unit for blood exchange
  • Blood moves from the triads to the vein through 3 zones:
    1. Zone 1: the periphery of the hepatic lobule, highest nutrient/oxygen levels
    2. Zone 2: transitional zone
    3. Zone 3: the center of the hepatic lobule, lowest nutrient/oxygen levels
      • Most sensitive to ischemic damage
Hepatic units

Schematic diagram of the 3 types of hepatic units. Note the portal triads located at the vertices of the hexagonal units and the 3 histological zones within the hepatic acinus.

Image by Lecturio.

Hepatocytes

  • Polyhedral cells organized into plates separated by sinusoids
  • Shape and number of the nuclei vary
  • Each cell has an apical biliary pole, which drains into one or more bile canaliculi, and a basolateral blood pole, which receives blood from the sinusoids.

Sinusoids

  • Capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries with discontinuous endothelium between hepatocyte plates
  • Receive oxygen-rich blood from the interlobular arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries and nutrient-rich blood from the interlobular veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins and conducts in toward the central veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins
  • Kupffer cells: specialized macrophages between the endothelial cells, which phagocytose old or damaged erythrocytes Erythrocytes Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes
  • Pit cells: liver-specific natural killer cells Natural killer cells A specialized subset of T-lymphocytes that exhibit features of innate immunity similar to that of natural killer cells. They are reactive to glycolipids presented in the context of the major histocompatibility complex (MHC) class I-like molecule, CD1D antigen. Lymphocytes that adhere to the endothelium, are dependent on Kupffer cells, and have tumor cell-lysing capability 
  • Perisinusoidal or space of Disse: space filled with blood plasma that lies between the sinusoids and hepatocytes
    • Contains Stellate or Ito cells: store vitamin A and play a role in collagen production (important in the development of cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis)
Plate of hepatocytes and sinusoid

Schematic representation of a sinusoid and plate of hepatocytes separated by the space of Disse. Note the specialized cells of the liver: Kupffer, Pit, and Stellate cells.

Image by Lecturio.

Neurovasculature

Blood supply

The liver has a special dual blood supply that provides a mix of oxygenated, deoxygenated, and nutrient-rich blood. 

  • Hepatic artery proper (HAP): supplies 25% of the liver’s blood supply and carries oxygenated blood 
    • Abdominal aorta → celiac trunk → common hepatic artery →  HAP
  • Portal vein: supplies 75% of blood supply, carries oxygen-poor, nutrient-rich blood drained from the abdominal organs
    • Formed most commonly by the union of the splenic and superior mesenteric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins
    • Additional tributaries: inferior mesenteric, cystic, and left and right gastric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins
Liver irrigation

Overview of the abdominal arterial blood supply. The celiac trunk is the 1st major branch of the abdominal aorta. It supplies the liver, stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach, spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen, pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas, and parts of the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus and duodenum with oxygenated blood. The celiac trunk gives off the left gastric artery, splenic artery, and the common hepatic artery. The common hepatic artery divides into the hepatic artery proper, gastroduodenal artery, and right gastric artery, all of which can be seen here.

Image by Lecturio.

Venous drainage

  • Sinusoids → central vein of each lobule → hepatic veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels
  • Portosystemic anastomoses: alternative routes of circulation ensuring venous drainage of abdominal organs even if blockage occurs in portal system. Anastomosis between:
    • The left gastric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins and the lower esophageal veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins 
    • The superior rectal veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins and the inferior and middle rectal veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins
    • The paraumbilical veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins and the small epigastric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins
    • The intraparenchymal hepatic branches of the right division of the portal vein and the retroperitoneal veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins 
    • The omental and colonic veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins with the retroperitoneal veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins
    • The ductus venosus and the IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels 
Hepatic portal vein system

Diagram of the venous portal system. The hepatic portal vein is formed most commonly by the union of the splenic vein and superior mesenteric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins. Other tributaries include the inferior mesenteric, cystic, and the left and right gastric veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins. As a whole, the portal system collects the venous drainage of the spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen, stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach, gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract, small and large intestines, and pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas.

Image: “Hepatic Portal Vein System” by OpenStax College. License: CC BY 3.0

Lymphatic drainage

Hepatic lymph nodes: located around the porta hepatis → celiac cluster of lymph nodes → cisterna chyli (dilated sac that receives lymph from the gastrointestinal [GI] trunk and 2 lumbar lymphatic trunks) → thoracic duct 

Innervation

  • Hepatic plexus (travels with the hepatic artery and portal vein)
  • Sympathetic fibers from the celiac plexus and superior mesenteric plexus
  • Parasympathetic fibers from the anterior and posterior vagal trunks
  • Glisson capsule innervated by the most inferior intercostal nerves
  • HAP has α and β adrenergic receptors innervated by splanchnic nerves

Biliary drainage

Bile canaliculi → intrahepatic bile ducts → left and right hepatic ducts → common hepatic duct → common bile duct common bile duct The largest bile duct. It is formed by the junction of the cystic duct and the common hepatic duct. Acute Cholangitis → duodenum

Gallbladder and biliary tract

Gallbladder and biliary tract Biliary tract Bile is secreted by hepatocytes into thin channels called canaliculi. These canaliculi lead into slightly larger interlobular bile ductules, which are part of the portal triads at the "corners" of hepatic lobules. The bile leaves the liver via the right and left hepatic ducts, which join together to form the common hepatic duct. Gallbladder and Biliary Tract

Image by Lecturio.

Functions of the Liver

Detoxification

The liver eliminates degradation products obtained via resorption from the GI tract. It makes fat-soluble substances water-soluble through enzymatic modification. This allows for excretion via biliary tracts or through urine.

  • Cytochrome p450 system: inactivates orally administered drugs via the first-pass effect
  • Degradation of ammonia Ammonia A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as ammonium hydroxide. Physiology of Acid-Base Balance into urea
  • Ethanol breakdown
  • Breakdown of bilirubin (glucuronidation) → excretion into bile

Metabolism

  • Carbohydrates:
    • Gluconeogenesis Gluconeogenesis Gluconeogenesis is the process of making glucose from noncarbohydrate precursors. This metabolic pathway is more than just a reversal of glycolysis. Gluconeogenesis provides the body with glucose not obtained from food, such as during a fasting period. The production of glucose is critical for organs and cells that cannot use fat for fuel. Gluconeogenesis (synthesis of glucose from amino acids, lactate, or glycerol)
    • Glycogenesis (synthesis of glycogen from glucose)
    • Glycogenolysis (breakdown of glycogen into glucose)
    • Glycolysis (breakdown of glucose into pyruvate, producing adenosine triphosphate (ATP))
  • Proteins: 
    • Production of albumin; globulins; acute phase proteins; transaminases; coagulation factors I (fibrinogen), II (prothrombin), V, VII, VIII, IX, X, XI, XII, and XIII; protein C; protein S; and antithrombin
    • Amino acid Amino acid Amino acids (AAs) are composed of a central carbon atom attached to a carboxyl group, an amino group, a hydrogen atom, and a side chain (R group). Basics of Amino Acids degradation
  • Lipids:  
    • Lipogenesis (storage of free fats as triglycerides) 
    • Ketogenesis (synthesis of ketone bodies) 
    • Fatty acid synthesis and degradation 
    • Production of bile acids, lipoproteins, and cholesterol
Liver metabolism diagram

Schematic diagram showing the various metabolic pathways the liver is involved in

Image by Lecturio.

Storage

  • Glycogen 
  • Lipoproteins 
  • Vitamins A, K, B12, B9 ( folate Folate Folate and vitamin B12 are 2 of the most clinically important water-soluble vitamins. Deficiencies can present with megaloblastic anemia, GI symptoms, neuropsychiatric symptoms, and adverse pregnancy complications, including neural tube defects. Folate and Vitamin B12), E, and D 
  • Iron and copper

Hormone production

  • Thrombopoietin
  • Insulin Insulin Insulin is a peptide hormone that is produced by the beta cells of the pancreas. Insulin plays a role in metabolic functions such as glucose uptake, glycolysis, glycogenesis, lipogenesis, and protein synthesis. Exogenous insulin may be needed for individuals with diabetes mellitus, in whom there is a deficiency in endogenous insulin or increased insulin resistance. Insulin-like growth factor 1
  • Angiotensinogen

Erythropoiesis Erythropoiesis Erythropoiesis starts with hematopoietic stem cells, which develop into lineage-committed progenitors and differentiate into mature RBCs. The process occurs in stages, and extrusion of the nuclei and organelles occurs prior to maturation. Thus, mature RBCs lack nuclei and have a biconcave shape. Erythrocytes

  • Site of fetal RBC production from week 6 of gestation until birth
  • Extramedullary erythropoiesis may occur in adulthood after bone marrow Bone marrow Bone marrow, the primary site of hematopoiesis, is found in the cavities of cancellous bones and the medullary canals of long bones. There are 2 types: red marrow (hematopoietic with abundant blood cells) and yellow marrow (predominantly filled with adipocytes). Composition of Bone Marrow irradiation, in various bone marrow Bone marrow Bone marrow, the primary site of hematopoiesis, is found in the cavities of cancellous bones and the medullary canals of long bones. There are 2 types: red marrow (hematopoietic with abundant blood cells) and yellow marrow (predominantly filled with adipocytes). Composition of Bone Marrow disorders (e.g., myelofibrosis, myelodysplastic syndrome, polycythemia vera Polycythemia vera Polycythemia vera (PV) is a chronic myeloproliferative neoplasm characterized by the overproduction of RBCs. In addition, the WBC and platelet counts are also increased, which differentiate PV from erythrocytosis seen with chronic hypoxia and other chronic conditions. Polycythemia Vera), and chronic anemias (e.g., thalassemia Thalassemia Thalassemia is a hereditary cause of microcytic hypochromic anemia and results from a deficiency in either the α or β globin chains, resulting in hemoglobinopathy. The presentation of thalassemia depends on the number of defective chains present and can range from being asymptomatic to rendering the more severely affected patients to be transfusion dependent. Thalassemia, sickle cell disease Sickle cell disease Sickle cell disease (SCD) is a group of genetic disorders in which an abnormal Hb molecule (HbS) transforms RBCs into sickle-shaped cells, resulting in chronic anemia, vasoocclusive episodes, pain, and organ damage. Sickle Cell Disease).

Clinical Relevance

Clinical evaluation

  • Abdominal examination Abdominal examination The abdominal examination is the portion of the physical exam evaluating the abdomen for signs of disease. The abdominal examination consists of inspection, auscultation, percussion, and palpation. Abdominal Examination: The examination of the liver is mostly based on palpation and percussion. The purpose of liver palpation is to approximate liver size and feel for tenderness and masses. The purpose of liver percussion is to measure the liver size.
  • Liver function tests Liver function tests Liver function tests, also known as hepatic function panels, are one of the most commonly performed screening blood tests. Such tests are also used to detect, evaluate, and monitor acute and chronic liver diseases. Liver Function Tests: can be divided into 3 categories:
    • Parameters of hepatocellular damage (transaminases, glutamate dehydrogenase, and AST/ALT ratio)
    • Parameters of cholestasis (e.g., γ-glutamyl transpeptidase, alkaline phosphatase, and direct and indirect bilirubin)
    • Parameters of hepatic synthesis (albumin, cholinesterase, and coagulation factors)
  • Normal abdominal imaging: Imaging is essential for accurately detecting focal liver lesions (e.g., abscess, tumor), but is limited in detecting and diagnosing diffuse hepatocellular disease (e.g., hepatitis, cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis).
    The types of imaging used are:
    • Hepatobiliary ultrasonography
    • Ultrasound elastography
    • Doppler ultrasonography
    • Computed tomography (CT) scan
    • Radionuclide liver scanning
    • Abdominal radiography
    • Magnetic resonance imaging (MRI)

Disorders

Neoplasms

  • Benign liver tumors Benign Liver Tumors The most common benign liver tumors include hepatic hemangiomas, focal nodular hyperplasia, and hepatic adenomas. These tumors are mostly asymptomatic and/or found incidentally on abdominal imaging. Benign Liver Tumors: cavernous hemangiomas, hepatocellular adenomas, and focal nodular hyperplasia. 
  • Liver cancer: hepatocellular carcinoma Hepatocellular carcinoma Hepatocellular carcinoma (HCC) typically arises in a chronically diseased or cirrhotic liver and is the most common primary liver cancer. Diagnosis may include ultrasound, CT, MRI, biopsy (if inconclusive imaging), and/or biomarkers. Hepatocellular Carcinoma (HCC) and Liver Metastases; intrahepatic cholangiocarcinoma; hepatoblastoma; angiosarcoma; hemangioendothelioma; liver metastases from GI, breast, and lung malignancies; and rare hepatic tumors (carcinosarcomas, teratomas, yolk sac tumors, carcinoid tumors Carcinoid tumors Carcinoid tumors are small, well-differentiated, slow-growing neuroendocrine tumors (NET). Carcinoid syndrome describes the signs and symptoms associated with unregulated vasoactive hormone production by neuroendocrine tumors. Carcinoid tumors are most commonly found in the GI and bronchopulmonary tracts. Carcinoid Tumors and Syndrome, and lymphomas). 

Infections

  • Viral hepatitis: mainly caused by primarily hepatotropic viruses A, B, C, D, and E, resulting in targeted inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the liver. Patients develop non-specific symptoms, such as nausea, vomiting, anorexia, and abdominal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain. Other viruses may cause hepatitis, including the Epstein-Barr virus Epstein-Barr Virus Epstein-Barr virus (EBV) is a linear, double-stranded DNA virus belonging to the Herpesviridae family. This highly prevalent virus is mostly transmitted through contact with oropharyngeal secretions from an infected individual. The virus can infect epithelial cells and B lymphocytes, where it can undergo lytic replication or latency. Epstein-Barr Virus, cytomegalovirus Cytomegalovirus CMV is a ubiquitous double-stranded DNA virus belonging to the Herpesviridae family. CMV infections can be transmitted in bodily fluids, such as blood, saliva, urine, semen, and breast milk. The initial infection is usually asymptomatic in the immunocompetent host, or it can present with symptoms of mononucleosis. Cytomegalovirus, and yellow fever virus Yellow Fever Virus Yellow fever is a disease caused by the yellow fever virus, a single-stranded, positive-sense RNA virus of the genus Flavivirus. Humans and primates serve as reservoirs, and transmission occurs from the bite of an infected female mosquito. Most patients present with fever and flu-like symptoms. Yellow Fever Virus.
  • Bacterial infections:
    • Pyogenic liver abscess Pyogenic liver abscess A pyogenic liver abscess is a polymicrobial infection arising from contiguous or hematogenous spread. Pyogenic liver abscess is the most common type of visceral abscess. Patients may present with a triad of fever, malaise, and RUQ pain. Pyogenic Liver Abscess (caused by many different types of pyogenic bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology: Overview)
    • Diffuse involvement, such as by Salmonella Salmonella Salmonellae are gram-negative bacilli of the family Enterobacteriaceae. Salmonellae are flagellated, non-lactose-fermenting, and hydrogen sulfide-producing microbes. Salmonella enterica, the most common disease-causing species in humans, is further classified based on serotype as typhoidal (S. typhi and paratyphi) and nontyphoidal (S. enteritidis and typhimurium). Salmonella enterica serotype typhi, Mycobacterium Mycobacterium Mycobacterium is a genus of the family Mycobacteriaceae in the phylum Actinobacteria. Mycobacteria comprise more than 150 species of facultative intracellular bacilli that are mostly obligate aerobes. Mycobacteria are responsible for multiple human infections including serious diseases, such as tuberculosis (M. tuberculosis), leprosy (M. leprae), and M. avium complex infections. Mycobacterium tuberculosis Tuberculosis Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis complex bacteria. The bacteria usually attack the lungs but can also damage other parts of the body. Approximately 30% of people around the world are infected with this pathogen, with the majority harboring a latent infection. Tuberculosis spreads through the air when a person with active pulmonary infection coughs or sneezes. Tuberculosis
  • Fungal infections, including Candida Candida Candida is a genus of dimorphic, opportunistic fungi. Candida albicans is part of the normal human flora and is the most common cause of candidiasis. The clinical presentation varies and can include localized mucocutaneous infections (e.g., oropharyngeal, esophageal, intertriginous, and vulvovaginal candidiasis) and invasive disease (e.g., candidemia, intraabdominal abscess, pericarditis, and meningitis). Candida/Candidiasis spp., Histoplasma Histoplasma Histoplasmosis is an infection caused by Histoplasma capsulatum, a dimorphic fungus. The fungus exists as a mold at low temperatures and as yeast at high temperatures. H. capsulatum is the most common endemic fungal infection in the US and is most prevalent in the midwestern and central states along the Ohio and Mississippi River valleys. Histoplasma/Histoplasmosis capsulatum
  • Parasitic infections, including Schistosoma Schistosoma Schistosomiasis is an infection caused by Schistosoma, a trematode. Schistosomiasis occurs in developing countries with poor sanitation. Freshwater snails are the intermediate host and are transmitted to humans through skin contact with contaminated fresh water. The clinical presentation occurs as a result of the host's immune response to antigens from the eggs. Schistosoma/Schistosomiasis spp. ( schistosomiasis Schistosomiasis Schistosomiasis is an infection caused by Schistosoma, a trematode. Schistosomiasis occurs in developing countries with poor sanitation. Freshwater snails are the intermediate host and are transmitted to humans through skin contact with contaminated fresh water. The clinical presentation occurs as a result of the host's immune response to antigens from the eggs. Schistosoma/Schistosomiasis), Plasmodium spp. ( malaria Malaria Malaria is an infectious parasitic disease affecting humans and other animals. Most commonly transmitted via the bite of a female Anopheles mosquito infected with microorganisms of the Plasmodium genus. Patients present with fever, chills, myalgia, headache, and diaphoresis. Malaria)

Inflammatory disorders

  • Alcoholic liver disease Alcoholic Liver Disease Alcoholic liver disease is a spectrum of disorders ranging from fatty liver to cirrhosis secondary to chronic alcohol abuse. Excessive and prolonged consumption of alcohol results in impairment of the lipolysis pathway, causing inflammatory changes within the hepatocytes. Patients typically present during the hepatitis stage with jaundice, fever, and abdominal pain. Alcoholic Liver Disease: progressive disease characterized by inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation and damage of the liver due to long-term excessive alcohol abuse.
  • Nonalcoholic fatty liver disease Nonalcoholic Fatty Liver Disease Nonalcoholic fatty liver disease is a spectrum of liver pathology that arises due to accumulation of triglycerides in hepatocytes. Risk factors include diabetes mellitus, insulin resistance, obesity, and hypertension, among others. Nonalcoholic fatty liver disease ranges from fatty liver or hepatic steatosis but can lead to nonalcoholic steatohepatitis (NASH), which features fatty deposits and inflammation. Nonalcoholic Fatty Liver Disease: progressive disease of the liver characterized by the accumulation of fat in the liver without the excessive intake of alcohol; often associated with obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity, diabetes, and elevated triglycerides.
  • Autoimmune hepatitis Autoimmune hepatitis Autoimmune hepatitis (AIH) is a rare form of chronic liver disease in which the immune system attacks the liver causing inflammation. It predominantly affects women. Clinical presentation ranges from asymptomatic cases to patients that present with symptoms of acute liver failure (jaundice, right upper quadrant pain). Autoimmune Hepatitis: progressive necroinflammatory process leading to chronic hepatitis or cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis. Characterized by the presence of circulating autoantibodies and high serum globulin concentrations. 
  • Fitz-Hugh-Curtis syndrome (perihepatitis): characterized by inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the liver capsule that occurs in women as a rare complication of pelvic inflammatory disease Pelvic inflammatory disease Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Gardnerella vaginalis. Pelvic Inflammatory Disease (PID).

Hereditary disorders

  • Hemochromatosis: a genetic autosomal recessive Autosomal recessive Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited. Autosomal Recessive and Autosomal Dominant Inheritancedisorder due to a mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations of the HFE gene, resulting in increased intestinal iron absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption. Presents with hepatomegaly, liver cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis, bronzed skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin, diabetes mellitus Diabetes mellitus Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, arthralgia, and cardiomyopathy Cardiomyopathy Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). Overview of Cardiomyopathies.
  • Wilson’s disease: an autosomal recessive Autosomal recessive Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited. Autosomal Recessive and Autosomal Dominant Inheritancemetabolic disorder in which copper excretion is impaired, leading to copper accumulation in the liver.
  • Dubin-Johnson syndrome: a rare, autosomal recessive Autosomal recessive Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited. Autosomal Recessive and Autosomal Dominant Inheritancedisorder that involves elevated levels of conjugated bilirubin in the serum that lead to a melanin-like pigment depositing in the liver, causing what is known as “black liver.”

Miscellaneous disorders

  • Portal hypertension Portal hypertension Portal hypertension is increased pressure in the portal venous system. This increased pressure can lead to splanchnic vasodilation, collateral blood flow through portosystemic anastomoses, and increased hydrostatic pressure. There are a number of etiologies, including cirrhosis, right-sided congestive heart failure, schistosomiasis, portal vein thrombosis, hepatitis, and Budd-Chiari syndrome. Portal Hypertension: an increase in the pressure in the portal vein. Most commonly caused by cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis, schistosomiasis Schistosomiasis Schistosomiasis is an infection caused by Schistosoma, a trematode. Schistosomiasis occurs in developing countries with poor sanitation. Freshwater snails are the intermediate host and are transmitted to humans through skin contact with contaminated fresh water. The clinical presentation occurs as a result of the host's immune response to antigens from the eggs. Schistosoma/Schistosomiasis, and portal vein thrombosis, but may be idiopathic.
  • Cirrhosis: a condition caused by chronic damage to the liver. Cirrhosis is characterized by hepatic parenchymal necrosis, which ultimately leads to fibrosis and liver insufficiency.
  • Budd–Chiari syndrome: a rare condition resulting from hepatic vein obstruction that leads to hepatomegaly, ascites Ascites Ascites is the pathologic accumulation of fluid within the peritoneal cavity that occurs due to an osmotic and/or hydrostatic pressure imbalance secondary to portal hypertension (cirrhosis, heart failure) or non-portal hypertension (hypoalbuminemia, malignancy, infection). Ascites, and abdominal discomfort.

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