Mrs Hampango notes

• Liver, pancreas and Biliary System

  Mrs. P. Hampango
• Liver


  The largest visceral organ in the body, primarily in the right hypochondrium and epigastric regions, extending into the left hypochondrium
• Liver


  • Consists of two surfaces: Diaphragmatic surface in the anterior, superior, and posterior directions; Visceral surface in the inferior direction
• Diaphragmatic surface of the liver


  Smooth and dome-shaped, lies against the inferior surface of the diaphragm
• Diaphragmatic surface of the liver

  • Associated with the subphrenic and hepatorenal recesses
  • The subphrenic recess separates the diaphragmatic surface of the liver from the diaphragm and is divided into right and left areas by the falciform ligament
  • The hepatorenal recess/Morrison's pouch is a part of the peritoneal cavity on the right side between the liver and the right kidney and right suprarenal gland
• Glisson's capsule


  The fibrous layer that covers the liver
• Lobes of the Liver


  • The liver is divided into right and left lobes by fossae for the gallbladder and the inferior vena cava
  • The right lobe of the liver is the largest lobe
  • On the visceral surface, the quadrate and caudate lobes are associated with the right lobe
  • The quadrate lobe is bounded on the left by the fissure for ligamentum teres and on the right by the fossa for the gallbladder
  • The caudate lobe is bounded on the left by the fissure for the ligamentum venosum and on the right by the groove for the inferior vena cava
  • Functionally, the quadrate and caudate lobes are related to the left lobe of the liver
• Functions of the Liver

  • Bile production and secretion
  • Detoxification
  • Storage of glycogen
  • Protein synthesis
  • Production of heparin and bile pigments
  • Erythropoiesis (in fetus)
• Associated Ligaments of the Liver

  • The liver is attached to the anterior abdominal wall by the falciform ligament
  • Except for a small area of the liver against the diaphragm (the bare area), the liver is almost completely surrounded by visceral peritoneum
  • The bare area of the liver is a part of the liver on the diaphragmatic surface where there is no intervening peritoneum between the liver and the diaphragm
  • The anterior boundary of the bare area is indicated by the anterior coronary ligament
  • The posterior boundary of the bare area is indicated by the posterior coronary ligament
  • Where the coronary ligaments come together laterally, they form the right and left triangular ligaments
• Relations of the Liver


  • The visceral surface of the liver is covered with visceral peritoneum except in the fossa for the gallbladder and at the porta hepatis (gateway to the liver)
  • The liver is related to the right anterior part of the stomach, the superior part of the duodenum, the lesser omentum, the gallbladder, the right colic flexure, the right transverse colon, the right kidney, the right suprarenal gland, and the oesophagus
• Porta hepatis


  The gateway to the liver, where the hepatic arteries and the portal vein enter, and the hepatic ducts exit
• Blood Vessels of the Liver

  • The blood supply of the liver is by the hepatic arteries and the portal vein, which enter the liver at the porta hepatis
  • The veins of the liver drain into the hepatic vein and into the inferior vena cava
• Biliary system


  A system of vessels and ducts which collect and deliver bile from the liver parenchyma to the second part of the duodenum
• Biliary system


  • Divided into intrahepatic and extrahepatic biliary trees
  • The intrahepatic ducts are formed from the larger bile canaliculi which come together to form segmental ducts, which then fuse close to the porta hepatis into right and left hepatic ducts
  • The extrahepatic biliary tree consists of the right and left hepatic ducts, the common hepatic duct, the cystic duct and gallbladder, and the common bile duct
• Gallbladder


  A flask-shaped, blind-ended diverticulum attached to the common bile duct by the cystic duct
• Gallbladder


  • In life, it is grey-blue in colour and usually lies attached to the inferior surface of the right lobe of the liver by connective tissue
  • It is divided into the fundus, the body and the neck
  • The fundus projects beyond the inferior border of the liver and is surrounded by peritoneum
  • The body lies in the fossa of the gallbladder
  • The neck is the narrow upper end of the gallbladder
• Functions of the Gallbladder


  • Stores bile
  • Absorbs water and determines bile concentration
  • Regulates pressure in the biliary system
• Location of the Gallbladder


  Located at the junction of the right ninth costal cartilage and lateral border of the rectus abdominis, which is the site of maximum tenderness in acute inflammation of the gallbladder
• Relations of the Gallbladder


  • Anteriorly: liver
  • Posteriorly: portal vein and epiploic foramen
  • Left side: hepatic artery/gastroduodenal artery
• Vascular Supply and Lymphatic Drainage of the Gallbladder


  • The cystic artery which usually arises from the right hepatic artery
  • Ductal arteries
  • Venous drainage: Cystic veins and multiple small veins in areolar tissue between the gallbladder and liver that enter the liver parenchyma to drain into the segmental portal veins
• Innervation of the Gallbladder and Extrahepatic Biliary Tree

  • Branches from the hepatic plexus
  • The retroduodenal part of the common bile duct and the smooth muscle of the hepatopancreatic ampulla of vater are also innervated by branches from the pyloric branches of the vagi
• Applied Anatomy of the Gallbladder and Biliary System


  • Referred pain: Pain caused by stretch of the common bile duct or gallbladder is referred to the central epigastrium
  • Involvement of the overlying somatic peritoneum produces pain which is more localized to the right upper quadrant
  • Extrahepatic Biliary Atresia: Occurs when the lumen of the biliary ducts is occluded owing to incomplete recanalization, associated with jaundice, white-colored stool, and dark-colored urine
  • Cholelithiasis (Gallstones): Small lumps of cholesterol, bile salts or a mixture of the two, which may form within the gallbladder, often asymptomatic but may be associated with pain, jaundice and systemic upset
• Pancreas

  A soft, lobulated organ that stretches obliquely across the posterior abdominal wall in the epigastric region, situated behind the stomach and extending from the duodenum to the spleen
• Pancreas


  • Pink in colour, with a firm, lobulated smooth surface
  • J-shaped, set obliquely and has a head, body, and tail regions
  • The head lies in the c-shaped curvature of the duodenum, and its tail extends to the left to touch the spleen
  • Has a length of 15cm-20 cm and 2.5cm-3.8cm broad, 1.2cm-1.8cm thick and weighs 90 grams
• Functions of the Pancreas

  • Both an exocrine and an endocrine gland
  • Endocrine glands are known as islets of Langerhans, secreting insulin and glucagon
  • Exocrine function is to produce most of the enzymes that digest ingested food in the small intestine, providing an alkaline medium for the activity of pancreatic enzymes
• Location of the Pancreas

  • Lies in the epigastric and left hypochondriac regions of the abdomen, at the level of the 1st and second lumbar vertebrae
  • The head lies to the right of the midline, with three borders (superior, inferior and right lateral), two surfaces (anterior and posterior) and one process, the uncinate process
  • The inferior border lies superior to the third part of the duodenum and is continuous with the uncinate process
  • The anterior surface of the head is covered in peritoneum and is related to the origin of the transverse mesocolon
  • The posterior surface of the head is related to the inferior vena cava, the right renal vein, the right crus of the diaphragm and usually the origin of the right gonadal vein
• Neck of the Pancreas

  Approximately 2 cm wide and links the head and body, defined as the portion of the pancreas that lies anterior to the portal vein, which is closely related to its upper posterior surface
• Body of the Pancreas

  • The longest portion of the gland, described as having three surfaces: anterosuperior, posterior and anteroinferior
• Tail of the Pancreas

  The narrowest, most lateral portion of the gland, lying between the layers of the splenorenal ligament
• Blood Supply of the Pancreas

  • Supplied by the coeliac axis and superior mesenteric artery, including the inferior pancreatico-duodenal artery, superior pancreatico-duodenal artery, and pancreatic branches from the superior mesenteric, middle colic, and splenic arteries
• Venous Drainage of the Pancreas

  • Veins drain into the splenic, superior mesenteric and portal veins
  • The head and neck drain primarily via the superior and inferior pancreaticoduodenal veins
  • The body and tail drain via small veins into the splenic vein
• Lymphatic Drainage of the Pancreas

  • They follow the arteries and drain into the pancreatico-splenic, coeliac and superior mesenteric group of lymph nodes
  • There is no evidence of lymphatic channels within the pancreatic islets
• Innervation of the Exocrine Pancreas

  • Parasympathetic component of the coeliac plexus and posterior vagus nerve
  • Sympathetic supply is from the 6th to 10th thoracic spinal segments, via the sympathetic contribution to the coeliac ganglia
• Applied Anatomy of the Pancreas

  • Pain arising in the pancreas is poorly localized and is usually referred to the epigastrium
  • Digestive disturbances due to enzyme deficiency
  • Carcinoma
  • Acute pancreatitis
• Bile production and secretion

  The liver produces bile, a digestive juice that helps break down fats in the small intestine. Bile is composed of bile salts, cholesterol, and bilirubin (a breakdown product of old red blood cells).
• Detoxification


  The liver is responsible for detoxifying harmful substances in the body. It neutralizes and transforms toxic substances into harmless ones, which can then be eliminated from the body.
• Storage of glycogen


  The liver stores excess glucose (sugar) in the form of glycogen. When the body needs energy, the liver converts the stored glycogen back into glucose and releases it into the bloodstream.
• Protein synthesis


  The liver produces many important proteins, including albumin (which helps maintain blood volume and prevent fluid leakage from blood vessels) and clotting factors (which help the blood clot to prevent excessive bleeding).
• Erythropoiesis (in fetus)


  During fetal development, the liver plays a role in the production of red blood cells (a process called erythropoiesis). However, this function is taken over by the bone marrow after birth.
• Production of heparin and bile pigments


  The liver produces heparin, a substance that helps prevent blood clotting, and bile pigments, which are the yellow-brown pigments found in bile.