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 A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of cn(H2O)n. The largest class of organic compounds, including starch; glycogen; cellulose; polysaccharides; and simple monosaccharides. Basics of Carbohydrates, proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis, 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 and Types), nutrient storage (e.g., iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements and vitamins), synthesis Synthesis Polymerase Chain Reaction (PCR) of coagulation factors Coagulation factors Endogenous substances, usually proteins, that are involved in the blood coagulation process. Hemostasis, formation of bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy, filtration, and storage of blood. The liver can be divided into 4 lobes or 8 segments. Microscopically, it is divided into hepatic lobules Lobules Breasts: Anatomy. Its main neurovascular bundle is found within the transverse fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes of the liver, also called the porta hepatis.
Last updated: 9 Mar, 2022
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).
Location of the liver within the abdominal cavity
Image by Lecturio.Frontal view Frontal View Imaging of the Spine and Spinal Cord of the abdominal cavity with the liver removed. Image shows the position of the liver in the peritoneal cavity Peritoneal Cavity The space enclosed by the peritoneum. It is divided into two portions, the greater sac and the lesser sac or omental bursa, which lies behind the stomach. The two sacs are connected by the foramen of winslow, or epiploic foramen. Peritoneum: Anatomy in relation to neighboring organs.
Image by Lecturio.Topography of the liver
Image by Lecturio.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: Anatomy’s hepatic flexure; the descending portion of the duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy forms the duodenal impression.
Image by Lecturio.The porta hepatis (also called the hepatic portal) is a transverse fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes that separates the caudate and quadrate lobes and serves as a passageway for the following:
Inferior view of the visceral surface of the liver, featuring the hepatic portal and surrounding hepatoduodenal ligament.
Image by Lecturio.Definition: Ligaments of the liver are double layers of visceral peritoneum Visceral peritoneum Peritoneum: Anatomy that fix the position of the liver by attaching it to the surrounding structures.
Coronary ligaments
Coronary ligaments
Knee Joint: Anatomy (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: Anatomy 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 Mesentery A layer of the peritoneum which attaches the abdominal viscera to the abdominal wall and conveys their blood vessels and nerves. Peritoneum: Anatomy 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: Anatomy of the liver. |
Hepatoduodenal ligament |
Portion of the lesser
omentum
Omentum
Peritoneum: Anatomy Extends from the porta hepatis to the superior part of the duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy contents: hepatic artery proper, portal vein, common hepatic duct |
Hepatogastric ligament |
Extends from the liver to the
lesser curvature
Lesser curvature
Stomach: Anatomy 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: Anatomy 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: Histology |
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: Anatomy (also known as ligamentum teres) |
Remnant of the intra-abdominal portion of the
umbilical vein
umbilical vein
Venous vessels in the umbilical cord. They carry oxygenated, nutrient-rich blood from the mother to the fetus via the placenta. In humans, there is normally one umbilical vein.
Prenatal and Postnatal Physiology of the Neonate 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: Anatomy |
Venous ligament (also known as ligamentum venosum) |
Remnant of the
ductus venosus
Ductus venosus
Development of the Heart Extends from the remnant of the intra-abdominal portion of the umbilical vein umbilical vein Venous vessels in the umbilical cord. They carry oxygenated, nutrient-rich blood from the mother to the fetus via the placenta. In humans, there is normally one umbilical vein. Prenatal and Postnatal Physiology of the Neonate 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: Anatomy |
Left fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes | Impressions of the round and venous ligaments |
Right fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes | 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: Anatomy and the inferior caval vein |
Anterior view of the diaphragmatic surface of the liver, featuring the falciform, triangular, round, and coronary ligaments Coronary ligaments Knee Joint: Anatomy. Note that 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: Anatomy extends from the free edge of the falciform ligament.
Image by Lecturio.Anterior view of the liver. The liver has been lifted to show the lesser omentum Omentum Peritoneum: Anatomy, which consists of the hepatogastric and hepatoduodenal ligament. This double layer of 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: Anatomy connects the liver with the lesser curvature Lesser curvature Stomach: Anatomy 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: Anatomy and the duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy.
Image by Lecturio.Anterosuperior view of a human liver
Image: “Hypoplastic left lobe of liver with accessory caudate lobe.” by Department of Anatomy, AIIMS, Rishikesh, Uttarakhand 249201, India. License: CC BY 3.0Posteroinferior view of a liver
Image: “Hypoplastic left lobe of liver with accessory caudate lobe.” by Department of Anatomy, AIIMS, Rishikesh, Uttarakhand 249201, India. License: CC BY 3.0Schematic 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 Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy 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: Anatomy, the branch of the hepatic artery supplies the hepatocytes with oxygenated blood. The bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy duct drains bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy from the hepatocytes towards larger ducts and the gall bladder Bladder A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination. Pyelonephritis and Perinephric Abscess.
Image by Lecturio.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.Schematic representation of a sinusoid Sinusoid Sinusoid, or discontinuous, capillaries allow larger proteins and full cells to pass through larger gaps. Capillaries: Histology and plate of hepatocytes separated by the space of Disse. Note the specialized cells of the liver: Kupffer, Pit, and Stellate cells Stellate cells Cerebellum: Anatomy.
Image by Lecturio.Schematic diagram of the histology of the liver. Note that the branch of the portal vein can be identified by the wide lumen and thin wall of smooth muscle cells. The branch of the hepatic artery has a smaller caliber surrounded by a thicker layer of smooth muscle. The walls of the bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy duct contain cuboid-shaped epithelial cells ( cholangiocytes Cholangiocytes Primary Sclerosing Cholangitis), which distinguish it from the hepatic artery.
Image by Lecturio.Histological cut of hepatic tissue, featuring a sinusoid Sinusoid Sinusoid, or discontinuous, capillaries allow larger proteins and full cells to pass through larger gaps. Capillaries: Histology (1), its discontinuous basal lamina Basal Lamina Capillaries: Histology (2), fenestrated endothelium Endothelium A layer of epithelium that lines the heart, blood vessels (vascular endothelium), lymph vessels (lymphatic endothelium), and the serous cavities of the body. Arteries: Histology (3), and the perisinusoidal space of Disse (4).
Image by Lecturio.Histological cut of hepatic tissue, featuring a central vein (top) and a portal triad (bottom).
Image by Lecturio.The liver has a special dual blood supply that provides a mix of oxygenated, deoxygenated, and nutrient-rich blood.
Overview of the abdominal arterial blood supply. The celiac trunk is the 1st major branch of the abdominal aorta Abdominal Aorta The aorta from the diaphragm to the bifurcation into the right and left common iliac arteries. Posterior Abdominal Wall: Anatomy. 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: Anatomy, 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: Anatomy, 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: Anatomy, 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: Anatomy and duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy with oxygenated blood. The celiac trunk gives off the left gastric artery Gastric artery Any of several branches of the splenic artery distributed to the greater curvature of the stomach. Stomach: Anatomy, splenic artery, and the common hepatic artery. The common hepatic artery divides into the hepatic artery proper, gastroduodenal artery, and right gastric artery Gastric artery Any of several branches of the splenic artery distributed to the greater curvature of the stomach. Stomach: Anatomy, all of which can be seen here.
Image by Lecturio.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: Histology. Other tributaries include the inferior mesenteric, cystic Cystic Fibrocystic Change, 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: Histology. 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: Anatomy, 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: Anatomy, 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: Anatomy, 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: Anatomy.
Image: “Hepatic Portal Vein System” by OpenStax College. License: CC BY 3.0Hepatic lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy: located around the porta hepatis → celiac cluster of lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy → cisterna chyli (dilated sac that receives lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs from the gastrointestinal [GI] trunk and 2 lumbar lymphatic trunks) → thoracic duct Thoracic Duct The largest lymphatic vessel that passes through the chest and drains into the subclavian vein. Lymphatic Drainage System: Anatomy
Bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy canaliculi → intrahepatic bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy ducts → left and right hepatic ducts → common hepatic duct → common bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy duct → duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy
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: Anatomy 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: Anatomy
Image by Lecturio.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 Urine Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the urethra. Bowen Disease and Erythroplasia of Queyrat.
Schematic diagram showing the various metabolic pathways the liver is involved in
Image by Lecturio.Neoplasms Neoplasms New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms. Benign Bone Tumors
Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease
Inflammatory disorders
Hereditary disorders
Miscellaneous disorders