Week 7 Lecture Notes on Stomach & Liver Anatomy PDF

dilated part of alimentary canal located in left hypochondriac, epigastric and umbilical regions à much of it lies under cover of lower ribs and costal cartilages functions: stores food mixes food with gastric secretions to form semi-fluid mass (chyme)...

dilated part of alimentary canal located in left hypochondriac, epigastric and umbilical regions à much of it lies under cover of lower ribs and costal cartilages functions: stores food mixes food with gastric secretions to form semi-fluid mass (chyme) controls rate of delivery of chyme to small intestine 2 surfaces (walls): anterior and posterior 2 borders: lesser curvature (shorter and on the right) and greater curvature (longer and on the left) incisura angularis (angular notch) à indentation located in lower part of lesser curvature 2 orifices: cardial and pyloric orifices cardial orifice à communicates esophagus with stomach cardial notch à indentation located between left border of esophagus and fundus of stomach pyloric orifice à communicates stomach with duodenum à it is surrounded by a https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 3 of 38  pyloric orifice à communicates stomach with duodenum à it is surrounded by a sphincter (pyloric sphincter), formed by a thickening of circular muscle layer of stomach https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 4 of 38  parts: cardia (cardial part) à area immediately adjacent to cardial orifice fundus à dome-shaped, upper part of stomach à limited inferiorly by horizontal line drawn across stomach starting at cardial notch à usually is full of gas body à extends from the level of cardial notch to the level of angular notch pyloric part à distal, funnel-shaped region of stomach à extends from angular notch to pyloric orifice à its proximal, wider part is known as pyloric antrum à its distal, narrower part is known as pyloric canal anatomical relations: anteriorly: anterior abdominal wall, left costal margin, diaphragm, left lobe of liver posteriorly: lesser sac, diaphragm, spleen, upper part of left kidney, left suprarenal gland, splenic artery, pancreas, transverse mesocolon Summary of the Blood Supply of the Stomach arteries: left gastric artery (branch of celiac trunk) right gastric artery (branch of proper hepatic artery) left gastroepiploic artery (branch of splenic artery) right gastroepiploic artery (branch of gastroduodenal artery) short gastric arteries (branches of splenic artery) all arteries are accompanied by veins of same name à all venous blood from stomach drains (directly or indirectly) into portal vein https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 5 of 38  Liver located in upper part of abdominal cavity, just beneath diaphragm, in right hypochondriac, epigastric and left hypochondriac regions à most of it lies under cover of lower ribs and costal cartilages surfaces: diaphragmatic and visceral diaphragmatic surface à convex, smooth, molded to undersurface of diaphragm visceral surface à faces inferiorly, posteriorly and to the left à molded to adjacent organs (gallbladder, esophagus, stomach, duodenum, right kidney, right suprarenal gland, right colic flexure) diaphragmatic and visceral surfaces are separated anteriorly by a sharp border (inferior border of liver) à no clear demarcation between them posteriorly visceral surface: has a series of grooves and fossae arranged like a letter “H” cross bar of H à porta hepatis (hilum of liver) à contains right and left hepatic ducts (collect bile produced by liver), branches of proper hepatic artery and portal vein (supply blood to liver), autonomic nerves and hepatic lymph nodes and vessels right limb of H (right sagittal fissure) à formed anteriorly by fossa for gallbladder and posteriorly by groove for IVC left limb of H (left sagittal fissure) à formed anteriorly by fissure for round ligament of liver (ligamentum teres hepatis) and posteriorly by fissure for ligamentum venosum during intrauterine life, umbilical vein carries oxygenated blood from placenta à umbilical vein joins portal vein à a large proportion of blood carried by umbilical vein bypasses liver and goes directly to IVC via ductus venosus at birth, umbilical vein and ductus venosus close and become fibrous cords à umbilical vein becomes round ligament of liver and ductus venosus becomes ligamentum venosum quadrate lobe à part of liver located anterior to porta hepatis, between fossa for gallbladder (right) and fissure for round ligament of liver (left) caudate lobe à part of liver located posterior to porta hepatis, between groove for IVC (right) and fissure for ligamentum venosum (left) https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 6 of 38  Peritoneal Ligaments of the Liver falciform ligament à two-layered peritoneal fold that connects diaphragmatic surface of liver to anterior abdominal wall (above umbilicus) à its liver attachment forms boundary between right and left lobes à has an inferior, free margin that contains round ligament of liver à posteriorly its 2 layers separate and become superior layer of coronary ligament coronary ligament consists of superior and inferior layers, which lie at some distance from each other à between them there is an area of liver devoid of peritoneum that is in direct contact with diaphragm à bare area of liver right and left triangular ligaments à right and left ends of coronary ligament, where its superior and inferior layers join each other lesser omentum à two-layered peritoneal fold that connects visceral surface of liver (porta hepatis and fissure for ligamentum venosum) to lesser curvature of stomach and 1st part of duodenum https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 8 of 38  Blood Circulation Through the Liver liver receives blood from 2 sources: proper hepatic artery (contributes about 30% of blood received by liver) à carries oxygenated blood (hepatic) portal vein (contributes about 70% of blood received by liver) à carries poorly oxygenated blood, rich in nutrients (absorbed from alimentary canal) artery and vein divide into progressively smaller branches à eventually, arterial and venous blood mix in liver capillaries (sinusoids) à blood is collected afterward by hepatic veins hepatic veins join forming progressively larger veins à eventually 3 large hepatic veins are formed (right, intermediate [middle] and left) which drain into IVC https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 9 of 38  Extrahepatic Biliary Ducts bile produced by hepatocytes is collected by small bile ducts within liver à these ducts join to form progressively larger ducts eventually, 2 large ducts are formed (right and left hepatic ducts), which exit liver via porta hepatis à after a short course, right and left hepatic ducts join to form common hepatic duct common hepatic duct descends within hepatoduodenal ligament and is joined by cystic duct (from gallbladder) to form common bile duct common bile duct lies first within hepatoduodenal ligament, then it passes posterior to 1st part of duodenum, and more inferiorly it lies posterior to head of pancreas (or embedded in it) à common bile duct can be compressed by tumors of head of pancreas causing jaundice common bile duct is usually joined by main pancreatic duct à they form a short, dilated chamber embedded in duodenal wall (hepatopancreatic ampulla or ampulla of Vater), which opens into 2nd part of duodenum by an orifice on the tip of a small mucosal elevation (major duodenal papilla) hepatopancreatic ampulla is surrounded by a sphincter (sphincter of hepatopancreatic ampulla or sphincter of Oddi) https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 10 of 38  Gallbladder pear-shaped sac lying on visceral surface of liver à stores bile and concentrates it by absorbing water parts: fundus à anterior, rounded end which projects below inferior border of liver à it is in contact with anterior abdominal wall at level of tip of right 9th costal cartilage body à middle part of gallbladder (between fundus and neck) à contacts visceral surface of liver (superiorly) and transverse colon and duodenum (inferiorly) neck à narrow, tapering end, opposite the fundus and directed toward porta hepatis à usually makes and S-shaped bend and becomes continuous with cystic duct https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 11 of 38  largest lymphoid organ of the body located in left hypochondriac region, between stomach and diaphragm, entirely sheltered by lower ribs (9th to 11th) àlacerations of spleen are commonly caused by fractured ribs functions: elimination of old and/or damaged blood cells filters antigens from blood and contributes to immune response against such antigens https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 14 of 38  surfaces: diaphragmatic à smooth and convex à faces posterolaterally à related to diaphragm surfaces: visceral à irregular and concave à faces anteromedially à related to stomach, left kidney, left colic flexure and tail of pancreas à also contains hilum of spleen borders: superior (usually notched) and inferior poles: anterior and posterior https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 15 of 38  long axis of spleen lies along 10th rib normal spleen cannot be palpated in the adult (anterior pole reaches normally as far forward as midaxillary line) intraperitoneal organ à its hilum is connected to stomach and left kidney by gastrosplenic and splenorenal ligaments, respectively splenorenal ligament contains splenic artery and vein and tail of pancreas gastrosplenic ligament contains short gastric arteries and veins and left gastroepiploic artery and vein blood supply à splenic artery (branch of celiac trunk) venous drainage à splenic vein à begins at hilum of spleen and runs to the right, inferior to splenic artery, and posterior to pancreas à drains into portal vein https://sites.google.com/view/grossanatomyii/week-7-lecture-notes 6/21/24, 2:17 PM Page 16 of 38