Liver Anatomy PDF

COLLEGE OF HEALTH SCIENCES DEPT OF ANATOMY G R O S S A N AT O M Y O F T H E L I V E R , E X T R A B I L L I A R Y A P PA R AT U S A N D T H E P O R T O - C AVA L A N A S T O M O S I S P R O F M. O. O YA K H I R E Lesson objectives  Know the gross and functional...

COLLEGE OF HEALTH SCIENCES DEPT OF ANATOMY G R O S S A N AT O M Y O F T H E L I V E R , E X T R A B I L L I A R Y A P PA R AT U S A N D T H E P O R T O - C AVA L A N A S T O M O S I S P R O F M. O. O YA K H I R E Lesson objectives  Know the gross and functional anatomy of structures which are accessory organs of the digestive system  Understand the exact anatomical location of the liver in the abdomen  Be able to describe the external features of the liver ; the surfaces, pouches and recesses  Understand the internal anatomy of the liver ; lobes segments  Know what constitutes the extrabilliary apparatus  Be able to describe the gall blader ,it’s relations and the parts  Know and describe the portocaval anastomoses  Describe blood supply, nerve supply  Applied concepts ,clinical annotations introduction  The liver digests food by producing bile to break down fats, removing toxins and breaking down and storing some vitamins and minerals.  The pancreas produces enzymes to help break down proteins, fats and carbohydrates.  The gall bladder stores the bile that is produced by the liver. When needed, bile passes into the small intestine, where it breaks down fat.  And except fat, all nutrients absorbed from the gastrointestinal tract are  initially transported to the liver by the portal venous system Introduction/LIVER  Second largest gland in the human body,next to the skin  Accessory organ of digestion, roles in detoxication, in rugulating metabolism  Wedged shaped ,Weighs about 1.5 gms  Surrounded by a fibrous conn tissue,  Glisson capsule ,receives approximately 1,500 mls of blood per minute mostly from the portal vein;75%  Protected by adjacent ribs (7th - 11th),diaphragm and abdominal wall muscles and sheath  Approximately 2/3rds of the liver can be donated and replacement will occur by Location, anatomical ;  Occupies right and left hypochondria and the epigastrium , the diaphragm  Directly underneath the anterior surfaces of 7th,8th,9th 10th and 11th ribs  Left lobe extends to the sternum and 5th rib on the left hemithorax at the left nipple  Inferior border is sharp, overlies the left costal margin  Palpable just below the costal margin  Moves with diaphragm during respiration  Normal anatomical position  Keep the groove for the IVC located in the posterior surface  vertical Neutral respiration…midline;4-8cm  Full expiration;-6-12 cm Rt mid clav.line Surface/living Anatomy External features Subphrenic recess&subhepatic space The greater sac is the upwards extension of the peritoneal cavity Which lies between diaphragm and the anterior and superior aspects of the diaphragmatic surface of the liver.  The falciform ligament, remnant of the ventral messentary  Which contains the obliterated umbilical vein extends between the liver and the anterior abdominal wall  It separates the subphrenic recesses into  right and left recesses  The subhepatic space Is the portion of the supracolic compartment of  the peritoneal cavity immediately inferior to the liver External features Pouch of Morrison  The hepatorenal recess (hepatorenal pouch; Morison pouch)  is the Posterior superior extension of the  Space which lies between the right part of  the visceral surface of the liver and the right kidney and suprarenal gland. Not normally filled with fluid  The hepatorenal recess is the most gravity- dependent part of the peritoneal cavity in the supine position; fluid draining from the omental bursa flows into this recess . The hepatorenal recess communicates anteriorly with the right subphrenic recess  Except in clinical conditions[ascites,haemoperitoneum, all recesses of the peritoneal cavity are potential spaces only, containing just enough peritoneal  fluid to lubricate the adjacent peritoneal membranes Diaphragmatic surface of the liver  The diaphragmatic surface of the liver is covered with visceral peritoneum,  except posteriorly in the bare area of the liver where  Here the surface is it in direct contact with the diaphragm.  The bare area is marked by the reflection  of peritoneum from the diaphragm to this part of the liver as  the anterior (upper) and posterior  (lower) layers of the coronary ligament  On the right these layers meet to form  the right triangular ligament and diverge toward the left to enclose the triangular bare area Extnl features  The anterior layer of the coronary ligament is continuous on the left with the right layer of the falciform ligament,  and the posterior layer is continuous with the right layer of the lesser omentum.  Near the apex (the left extremity) of the wedge-shaped liver,  the anterior and posterior layers of the left part of the coronary ligament meet to  form the left triangular ligament.  The IVC lodges in a deep groove for the vena cava within the bare area of the liver External features cntd External features/Relations Extnl features Surfaces of the Liver  Diaphragmatic surface  Convex superiorly, makes contact with diaphragm and anterior abdominal wall, and a cardiac impression  This is the small depressed area on the superior surface  Divided into Anterior, posterior (including the bare area ),superior surface which has cardiac indentation  Visceral surface (inferior surface), is irregular, concave, directed downward, backward, and to the left, it is the most clearly defined border of the liver  it is related by connective tissues and ligaments to the stomach and duodenum, the right colic flexure, and the  thesemake impressions on the liver  The right anterior surface is separated from the visceral surface by a sharp inferior border  The bare area is part of the posterior area  Peritoneal ligaments of the liver  They help stabilize the organ in it’s position  Very important during sporting activities and in cases of RTA by their attachments  Falciform ligament  Coronary ligament  Right and left triangular ligaments  Ligament teres; obliterated umbilical vein  The lesser sac  Show all in the illustrations Inferior /visceral surface A confifiguration; two sagittal lines lines joined together by a horizontal line Is featured on the visceral surface of the liver  The horizontal fissure is the Porta hepatis  The right fissure is the continuous groove formed anteriorly by the fossa for the Gallbladder and posteriorly by the groove for the Vena cava.  The Umbilical (left sagittal) fissure is the continuous groove formed anteriorly by the fissure for the Round ligament  and posteriorly by the fissure for the LigamentumVenosum.  The round ligament of the liver (L. ligamentum teres hepatis)  is the fibrous remnant of the umbilical vein, which carried oxygenated nutrient-rich blood from the placenta to the fetus  The round ligament and small para-umbilical veins course in the free edge of the falciform ligament.  The ligamentum venosum is the fibrous remnant of the fetal ductus venosus,  which shunted blood from the umbilical vein to the IVC, bypassing the liver.  The falciform ligament ascends to the liver from the umbilicus, somewhat  to the right of the midline, and bears the ligamentum teres in its free border. The ligamentum teres passes into its fissure in the inferior surface of the liver while the falciform ligament passes over the dome of the liver and then divaricates. Its right limb joins the upper layer of the coronary ligament and its left limb stretches out as the long narrow left triangular ligament which, when traced posteriorly and to the right, joins the lesser omentum in the upper end of the fissure for the ligamentum venosum.  ANATOMICAL LOBES OF LIVER  Externally, the liver is divided into two anatomical lobes and two accessory  lobes by the reflections of peritoneum from its surface, the fissures formed in  relation to those reflections and the vessels serving the liver and the gallbladder.  The classification does not consider the blood supply of the liver  These superficial “lobes” are not true lobes as the term is generally used in  relation to glands and are only secondarily related to the liver’s internal architecture.  The midline plane defined by the attachment of the falciform ligament anteriorly and the fissures for ligamentum teres and ligamentum venosum (ligament of Arantius  The left sagittal fissure separates a large right lobe from a smaller left lobe  On the visceral surface, which is slanted the right and left sagittal fissures course on each side  and the porta hepatis separates—two accessory lobes (parts of the anatomic right lobe):  the quadrate lobe anterio inferiorly and the caudate lobe posterio superiorly.  So it is not acceptable to the surgeons - Right lobe Quadrate lobe;- between the fossa for gall bladder and fissure for ligamentum Teres Caudate lobe ‘- between the fissure for Ligamentum venosum and the IVC FUNCTIONAL CLASSIFICATION The cantilie’s line extends from the groove for IVC posteriorly to the middle of the gall bladder fossa posteriorly The plane contains the middle hepatic vein The connective tissue from the gall bladder runs up to reach the IVC And the plane divides the liver into right and left lobes  Functional classification  Therefore based on Couinaud’s segentation of the liver  Left of couinad’s plane..segments 2,3,4a and 4b  Right of the plane ,segments 5,6,7 and 8  Clinical relevance…used for  Radiological investigations;- ultrasonography and hepatectomy  i.e middle hepatic vein is identified and tied off and the surgical field explored Based on functional anatomy/blood supply Based on the CANTIE’SLINE Right lobe Right hepatic artery Right branch of portal vein Right hepatic duct Left lobe Left hepatic artery Left branch of portal vein Left branch of bile duct  The lesser omentum, passes from the liver to the lesser curvature of the stomach and the first 2 cm of the superior part of the duodenum  It encloses the portal triad (Bile duct, Hepatic artery,  and Hepatic portal vein),CBD,MHD,PV  The , free edge of the lesser omentum is thick and extends between the porta hepatis and the duodenum (the hepatoduodenal ligament) ,-lat  It encloses the structures that traverse the porta hepatis. The rest of the lesser omentum,  Is the flat Hepatogastric ligament, extends between the groove for the ligamentum venosum and the lesser curvature of the stomach.medl  Common bile duct, main hepatic duct, portal vein  The portal triad passes  between the layers of the hepatoduodenal ligament to enter  liver at the porta hepatis.  The common hepatic artery passes  between the layers of the hepatogastric ligament  Lying in the porta hepatis (which is 5 cm (2 in) long) are:  1 the common hepatic duct – anteriorly and to the right;  2 the hepatic artery – anteriorly and to the left;  3 the portal vein – posteriorly.  As well as these, autonomic nerve fibres (sympathetic from the coeliac axis and parasympathetic from the vagus), lymphatic vessels and lymph nodes are found there. Lesser omentum,foramen of Winslow Porta hepatis Impressions on the visceral surface right side of the anterior aspect of the stomach (gastric and pyloric areas). superior part of the duodenum (duodenal area). lesser omentum (extends into the fissure for the ligamentum venosum). gallbladder (fossa for gallbladder). right colic flexure and right transverse colon (colic area). right kidney and suprarenal gland (renal and suprarenal areas Hepatic sectors There are four main hepatic sectors in the physiological right and left lobes Left sectoral sector Left medial /quadrate lobe Right anterior Right posterior left lateral and left medial segments are divided by the falciform ligament, subdiving it Into lateral and medial subsegments and not into right and left lobes Sectoral anatomy QOUINAUD’S SEGMENTS  Similar to the bronchial segments of the lung  Each segment is supplied by a single portal vein, hepatic artery and bile duct  Right lobe.segments V,VI,VII,VIII  Left lobe..segments I, II,III,and IV Segment 1 is the caudate lobe, has independent blood supply from right and left portal vein and hepatic artery. The hepatic vein from this segment empties directly into the IVC Segment IV on the visceral surface is the quadrate lobe (OLD TERM),now left medial ligament Riedal’s lobe of the liver Tonguelike projection from the lower lobe , Blood supply Right lobe segments ;-right hepatic artery,right branch of Extra hepatic biliary apparatus(EBA)  Introd  The apparatus involves transportation of blood to the liver, concentration/processing and return to the duodenum  It consists of right and left hepatic ducts  The common hepatic ducts  Gall bladder  Cystic duct  Common bile duct  Begins with right and left hepatic ducts  Which unite to formthe common hepatic duct The right and left lobes drain into the corresponding ducts Left duct drains 3 segments,- II, III and IV Right duct drains 6 segments; V,VI, VII and VIII The caudate lobe(segment one ) is drained by both ducts Common hepatic duct ;-union of Left and Right hepatic duct Formed external(extrabiliary) to the liver paranchyma closely applied to the right end of the porta hepatis The common hepatic duct decends for approximately 3cm and then joined by the cystic duct at an acute angle to form the This arrangement results in a triangle; hepatocystic triangle of Calot Boundaries Medial;-common hepatic duct Base./superior - inferior surface of the liver Lateral ;-cystic duct Sketch for simplicity  This arrangement results in a triangle; hepatocystic triangle of Calot  Boundaries  Medial;-common hepatic duct  Base./superior - inferior surface of the liver  Lateral ;-cystic duct Triangle of Calot Contents and clinicals Cystic artery Right hepatic artery Cystic lymph node of Lund Connective tissue Aberrant accessory ducts and arteries occassionally In chelecystectomy , the arteries must be identified and isolated to prevent disasterous heamorrhage Infllamatory conditions,,cholecystitis, DM, Cholelithiasis,cancer etc Gall bladder  Gall bladder is a Pyriform,pear (AVOCADO) shaped organ, lies in a fossa at the inferior (visceral) surface of the right liver between segment IV and V ;-junction of the left and right lobes in the right hypochondrium  It is divided into neck,body and fundus  It is 7-10 cm long a 2.5-3cm in width ,with a capacity of 50-60 mls  Volume increases during fasting ,and vice versa ; fasting decreases movement and causes increase in concentration of cholesteol in bile  Bile stored in the gall bladder is transmitted to the 2nd part of the duodenum  The neck is the upper narrow end close to the porta hepatis  The Posterior medial wall of neck features a pouch;  the Hartman pouch which projects downwards and backwards  It merges inferiorly with the cystic duct  The fundus is the dilated portion  which lies about 1cm below the inferior margin of the liver  At an angle between the lateral border of the Rectus abdominis and the 9th costal cartilage  It is almost completely intraperitoneal  Body of the gall bladder  Upper surface is not covered by peritoneum; bare are of the liver;  attachment is by connective tissue  Superior surface is related to the first part of the duodenum  Ducts of Luschka(DOL)and floating gall bladder.  Are occassional findings  The former present as ducts measuring 1-2 mmlocated typically in the fossa for GB in the lower part of the right hepatic lobe ,drains into the right common bile duct  Latter occurs in approximately 5% of populations ; the GB lies completely surronded by peritoneum and attached to the undersurface of the cystic fossa where the peritoneum is reflected from the liver  Also described as GB displaced inferiorly with a long cystic duct  Histology /microscopy in brief from inside -  Inner mucosal lining composed of simple columnar epithelium which possese microvilli with properties for absorption  Lamina propria  Lamina propria  Layer of randomnly oriented smooth muscle cells, collagen and elastic fibers  Layer(muscularis externa)  Serosa ; consists of mesothelium and loose connective tissue where this layer is not attached to the liver  /called adventitia where this layer is attached to the liver  Note that muscularis mucosa and submucosa are absent in the wall of the GB Anatomical relations Anterosuperior..Anterior abdominal wall, inferior border of the liver Posterior….. Duodenum ;proximalportion Transverse colon Inferior ,extrahepatic bile ducts Cystic duct  Connects the neck of the gall bladder to the Common hepatic duct  Forming the common bile duct  The confluence forms an acute angle triangle  The duct is 2-3cmlong and 2-3mm in diameter  Within the lumen there are multiple mucosal folds called spiral mucosal folds of Heister , no valvular function as at date  It is supplied by the cystic artery and right hepatic artery and drained by cystic vein  Clinicals. Calculus,cystic duct duodenal fistula primary schlerosing cholangitis,ca,etc Commonbile duct(CBD)  Now known as the bile duct  Is formed by union of common hepatic duct and cystic duct  Runs posterior /behind the first part of Duodenum along with the Gastroduodenal artery ,then behind the pancreas  Ends by uniting with the pancreatic duct to form the Hepato pancreatic Ampulla  of Vater  It is approximately 8cm long and 5-8 mm diameter  It is divided into four parts  Supraduodenal ,-descends in the free edge of the lesser omentum in front of the portal vein and right hepatic artery  Retroduodenal ;passes posterior to the first part of the Duodenum, anterior to the IVC, lateral to the portal vein  Intra-pancreatic part; runs in a groove in the posterior wall of the pancreas  to enter the second part of the duodenum where it joins the commonpancreatic duct Illustration ;-intramural part  Intramural part ;runs obliquely through wall of pancreas to form  the ampula of varta at the major duodenalpapilla  Occassionally, the common bile duct and common pancreatic duct unites external to the wallof the duodenum  They commonly unite and empty into the duodenal wall  The ducts may also occassionally enter separately Hepatopancreatic sphincter of Glisson (OT-Sphincter of Oddi)  Anatomical structure/landmark  Acts as asphincter to control actions of pre ampullary(distal)bile and pancreatic ducts  contains within the wallof the duodenum, four smooth muscle sphincters  Superior and inferior sphincter choledochus ;-Sphincter of Boyden  Sphincter pancreaticus  Sphincter ampullae  The sphincter mechanism is independent of dodenalmusculature Blood supply of the EBA Arteries.Right and left hepatic arteries  Cystic artery  Posterior superior pancreaticoduodenal artery  Retro-duodenal artery  Note that blood supply is mainly from the lower aspect of the liver ;-ischemic necrosis of vital structures Veins.-hepatic veins drain hepatic ducts and deep aspect of the gall bladder via tiny vessels  Rest of EBA …Portal vein  Lymphatic drainage :-hepatic ,coeliac and pancreatic groups of lymph nodes Nerve supply  Celiac plexus through  Sympathetic plexus ;preganglionic fibers through the greater splanchnic nerves to the celiac ganglion  Afferent visceral nerve fibers which travel through the greater splanchnic nerves  Parasympathetic ;vagus ;CN X  Sensory fibers from the gall bladder run in the right phrenic nerve ;C3,4 and 5  Referred tip of shoulder pain in cholecystitis Applied concepts  Triangle of Calot; laparoscopy ,minimally invasive surgery  Phrygian cap ;anatomic variant; fundus of gall bladder folding onto the body ;no pathologic significance  Hartman’s pouch; gall stones commonly impact here, surgery indicated  Murphy sign ; discussed  ERCP;-endoscopic retrograde cholangio- pancreatography The Portocaval Anastomosis  Porto; tributrs of the portal vein  Caval ;tributaries of systemic veins , IVC, SVC  Basic principle  In the healthy state,venous portal blood passes through the liver and the hepatic veins and empty into the IVC  Small caliber veins connect to transfer blood between the portal and systemic veins  There are no valves in the portal vein and it’s tributaries.  As a result these other veins become collateral and become dilated/varicose when there is obstruction in the direct route  See illustration Portocaval anastomosis  Participating vessels Sup mess vn  Inf mess vn plus splenic vein  Left gastric vein  Superior rectal vn  Paraumbilical vn,left part of portal vein  Retroperitoneal ven  Colonic veins Porto systemic anastomosis Porto caval anastomosis illustrated SITES Paraumbilical;-Systemic Portal..paraumbilical vein in ligament of teres,,,obliterated left umbilical vein Which carries oxygenated blood to the fetus which in obstructive liver dxx;-creates high pressure can be recanalized by retrograde blood flow With intercostal ,thoraco epigastric, deep and superfcl Sites continued Upper part of anal canal..systemic component…inferior and middle messenteric veins, drain seminal vesicle, prostate and urinary bladder At the dentate line tributaries of internal iliac vein join the IVC They will anastomose with superior rectal Veins at level of Dentate line; one third below surgical anal canal defined as the area located between the anorectal ring and the anal verge Sites cntd ; point which demarcates ectoderm of external squamous epithelium and rectal entodermal mucosa  Portal component; Blood from the superior rectal vein, which is the terminal branch of the infer mess vein  , is joined by that in the splenic vein to enter the IVC  Also  Abdominal part of esophg;- left gastric branches portl comp;- anastms with  ;- oesophagl branches of the azygos and hemiazygous vns; Systemic comp Sites cntd Bare area..around coronary ligaments of the liver ; central veins ;hepatic component anastomoses with intercostal and phrenic vein, and in some texts with azygous and hemiazygous veins(ystemic Bare area of colon Portal.colonic and duodenal veins Systemic.-twigs from retroperitoneal veins ,veins Sites around the kidneys, lumbar veins and veins of the posterior abdominal wall patent ductus venosus Clinical setting ‘Perilobular fibrosis involving the hepatocytes Engorgement and distension of portal vein and spleen Clinicals Liver cirrhosis Portal hypertension above 40mm hg Haematemesis , continous, mops up blood cloth.- DIC Note differentia diagnosis.blood is not frothy END