sign in sign up
<<
Home , Cystohepatic triangle, Esophageal veins, Systemic venous system

Abdominal cavity the fourth lecture The –fourth lecture

Pancreas Intrahepatic and extrahepatic bile ducts Gallbladder The portal and portal-systemic anastomoses Spleen Pancreas An elongated, accessory digestive gland Secondary retroperitoneal organ Transversely across the posterior Lies posterior to the stomach between the duodenum on the right and the spleen on the left The transverse mesocolon attaches to its inferior margin Pancreas - parts

Head Neck Body Tail Pancreas The neck overlies the 1st and 2nd lumbar vertebrae in the transpyloric plane Its head is to right and inferior to this plane Its body and tail are to the left and superior to this level Lies deep in the abdominal cavity, it is usually not palpable Pancreas - function

An exocrine secretion (pancreatic juice from the acinar cells) that enters the duodenum through the main and accessory pancreatic ducts Endocrine secretion (glucagon and insulin from the pancreatic islets) that enter the blood Pancreas – the head

Expanded part Is embraced by the C-shaped curve of the duodenum to the right of the superior mesenteric vessels Firmly attaches to the medial aspect of the descending and horizontal part of duodenum Rests posteriorly on the inferior vena cava, right renal and vein and left Pancreas – the head

The common bile duct lies in a groove on the posterosuperior surface of its Pancreas – the uncinate process

A projection from the inferior part of the head Extends medially to the left Extends posterior to the superior mesenteric artery Pancreas – the neck

Short Overlies the superior mesenteric vessels, which form a groove in its posterior aspect The anterior surface is covered with , is adjacent to the pylorus of the stomach Posterior to its the superior mesenteric vein joins with the splenic vein to form the portal vein Pancreas – the body Continues from the neck and lies to the left of the superior mesenteric vessels Passing over the aorta and L2 vertebra The anterior surface is covered with peritoneum and forms part of the stomach bed The posterior surface is devoid of peritoneum and is in contact with aorta, superior mesenteric artery, left suprarenal gland, left kidney and renal vessels Pancreas – the tail

Lies anterior to the left kidney Is closely related to the hilum of the spleen and the left colic flexure Is relatively mobile and passes between the layers of the splenorenal The tip of tail is usually blunted and turned superiorly The main pancreatic duct (duct of Wirsung) Begins in the tail and runs through the parenchyma of the gland to the head In the head turns inferiorly and is related to the bile duct Unites with the bile duct to form hepatopancreatic ampulla The sphincter of its, the sphincter of the bile duct and the hepatopacreatic sphincter (sphincter of Oddi) are smooth muscle sphincters that control the flow of bile and pancreatic juice into descending part of duodenum (major duodenal papilla, Vater papilla) The accessory pancreatic duct (duct of Santorini) Drains the uncinate process and the inferior part of the head of the pancreas Opens into the duodenum at the summit of the minor duodenal papilla Usually communicates with the main pancreatic duct In some cases is greater than the main pancreatic duct and the two are not connected so it carries most of the pancreatic juice The of the pancreas

Body and tail: splenic artery (10 branches)

Head: superior pancreaticoduodenal artery: anterior and posterior inferior pancreaticoduodenal artery (anterior and posterior branch) The of the pancreas

Are tributaries of the splenic and superior mesenteric parts of the portal vein

Most of them empty into the splenic vein The lymphatic vessels of the pancreas

Follow the blood vessels Most of them end in the pancreaticosplenic nodes that lie along the splenic artery Some of them end in the pyloric lymph nodes Efferent vessels from the pancreaticosplenic nodes and pyloric nodes drain to the celiac, hepatic and superior mesenteric lymph nodes The nerves of the pancreas

Derived from the vagus and thoracic splanchnic nerves passing through the diaphragm The fibers passing along the arteries from the celiac plexus and superior mesenteric plexus To pancreatic acinar cells and islets passing parenchymal (sympathetic and parasympathetic) fibers and to vasa passing vasomotor (sympathetic) fibers Liver

The largest gland in the body

Weighs approximately 1500gm and accounts for approximately one-fortieth of adult body weight

Lies inferior to the diaphragm, which separates it from the pleura, lungs, pericardium and heart

Has many metabolic activities, stores glycogen and secretes bile Surface anatomy of the liver

Lies mainly in the right upper quadrant Is hidden and protected by the thoracic cage and diaphragm Lies deep to ribs 7 through 11 on the right side and crosses the midline toward the left niple Occupies most of the right hypochondriac, epigastric and extends into the left hypochondriac region The surfaces of the liver Diaphragmatic Surface

Visceral surface (posteroinferior)

Surfaces are separeted anteriorly by its sharp inferior border

Is covered by the subperitoneal fibrous capsule (Glisson’s capsule) The diaphragmatic surface of the liver

Is smooth and dome-shape Is largely separated from the diaphragm by the subphrenic recesses between the anterior part of liver and the diaphragm Is covered with visceral peritoneum except posteriorly in the bare area of the liver The hepatorenal recess (Morison’s pouch) Is a deep recess on the right side extending superiorly between the liver anteriorly and the kidney and suprarenal gland posteriorly, fluid draining from the omental bursa flows into the recess Communicates anteriorly with the right subphrenic recess The bare area of the liver

The liver lies in contact with the diaphragm

Is demarcated by the reflection of peritoneum from the diaphragm to it as the anterior (upper) and posterior (lower) layers of the The visceral surface of the liver

Right and left sagittal fissure Is covered with visceral peritoneum except at the bed of the gallbladder and the porta hepatis Is related to the stomach, superior part of duodenum, lesser omentum, gallbladder, right colic flexure and the right transverse colon, right kidney and suprarenal gland Functional parts of the liver

The segmentation of the liver is based on the principal divisions of the and portal vein and accompanying hepatic ducts Functional parts of the liver Has functionally independent right and left parts (portal lobes, right and left liver) that are approximately equal in size On the visceral surface the right liver is demarcated from the left liver by the gallbladder fossa inferiorly and the fossa for the inferior vena cava superiorly Each part has its own blood supply from the hepatic artery and portal vein and its own venous and biliary drainage Anatomical (nonfunctional) lobes of the liver

Right lobe Left lobe Quadrate lobe Caudate lobe The liver – the left lobe

Is separated from caudate and quadrate lobes on the visceral surface by the fissure for round ligament of the liver and the fissure for the

Is separated on the diaphragmatic surface by the attachment of the The round ligament of the liver

Is the fibrous remnant of the that carried well-oxygenated and nutrientrich blood from the placenta to the fetus The ligamentum venosum of the liver

Is the fibrous remnant of the fetal that shunted blood from the umbilical vein to the inferior vena cava, short circuiting the liver Vessels of the liver

Receives blood from two sources:

The portal vein (70%)

The proper hepatic artery (30%) The portal vein Drains venous blood from the , spleen, pancreas, and gallbladder to the sinusoids of the liver From sinusoids blood is conveyed to the by the hepatic veins that drain directly to the inferior vena cava Is formed by the union of the superior mesenteric and splenic veins posterior to the neck of the pancreas The portal vein Collects poorly oxygenated but nutrient-rich blood from the abdominal part of the gastrointestinal tract The main channel of the portal venous system Branches end in expanded – the venous sinusoids of the liver The inferior vena cava The largest vein in the body Returns poorly oxygenated nonportal blood from the lower limbs, most of the back, the abdominal walls, the abdominopelvic viscera, Begins anterior to the L5 vertebra by the union of the common iliac veins The union occurs approximately 2.5 cm to the right of the median plane, inferior to the bifurcation of the abdominal aorta The inferior vena cava (IVC) Ascends on the right side of the bodies of the L3 through L5 vertebrae and on the right psoas major to the right of the abdominal aorta Leaves the by passing through the caval foramen in the diaphragm to enter the thorax Almost all blood from the digestive tract is collected by the portal system and passes through the hepatic veins to the IVC The portal venous system

Communicates with the systemic venous system through: The The rectal veins (inferior and middle) Superficial epigastric veins Retroperitoneal veins The portal venous system

Communicates with the systemic venous system through: The esophageal veins to the azygos vein through the left gastric vein The portal venous system

Communicates with the systemic venous system through: The rectal veins (inferior and middle) draining into the inferior vena cava and the superior rectal vein continuing as the inferior mesenteric vein The portal venous system

Communicates with the systemic venous system through: Paraumbilical veins anastomosing with superficial epigastric veins The portal venous system

Communicates with the systemic venous system through: Twigs of colic veins anastomosing with retroperitoneal veins Portal-systemic anastomoses

Are important clinically in the advent of an intrahepatic or extrahepatic portal venous block because of liver disease or physical pressure (tumour) Blood from gastrointestinal tract can still reach the right of the heart through several, alternate routes Blood can flow in a reverse direction to the inferior vena cava because the portal vein and its tributaries have no valves Portal hypertension- the

Produces enlarged varicose veins at the sites of anastomoses between portal and systemic veins Veins may become so dilated that their walls rupture, resulting in hemorrhage (esophageal varices) Portal hypertension – the head of Medusa

The paraumbilical veins may become varicose and look somewhat like small snakes radiating under the skin around the umbilicus (caput medusae - the head of Medusa) Portal hypertension- hemorrhoids

Are not typically related to the portal hypertension but can occur The hepatic artery Caries well- oxygenated blood from the abdominal aorta Is divided into: Common hepatic artery – from celiac trunk to the origin of the gastroduodenal artery Hepatic artery proper – from the origin of the gastroduodenal artery to its bifurcation into right and left hepatic arteries Vessel distribution

Within each part the primary branchings of the portal vein and hepatic artery are consistent enough to form vascular segments A horizontal plane through the right lobe and lateral division of the left lobe, plus the caudate lobe, divides the liver into eight vascular segments Between the segments are intersegmental veins The porta hepatis (hepatic portal)

Transverse fissure on the visceral surface between the caudate and quadrate lobes, where vessels and ducts enter or leave the liver Gives passage to the: - Portal vein - Hepatic artery proper - Hepatic nerve plexus - Hepatic ducts - Lymphatic vessels 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 The is a thick, free edge of its, encloses portal vein, bile duct, hepatic artery proper, a few lymph nodes, lymphatic vessels and the hepatic plexus of nerves The extends between the groove for the ligamentum venosum of the liver and the lesser curvature of the stomach The lymphatic vessels of the liver Drain to the hepatic lymph nodes scattered along the hepatic vessels and ducts in the lesser omentum and to into the celiac lymph nodes Drain into phrenic lymph nodes or join deep lymphatics that have accompanied the hepatic veins converging on the inferior vena cava and pass through the diaphragm into the posterior mediastinal lymph nodes The lymph drainage of the liver

From the posterior surface of the left lobe toward the esophageal hiatus of the diaphragm to end in left gastric lymph nodes From the anterior central diaphragmatic surface along falciform ligament to parasternal lymph nodes Along the round ligament of the liver to the umbilicus and lymphatics of the anterior abdominal wall The nerves of the liver

Derived from the hepatic nerve plexus, the largest derivative of the celiac plexus Accompanies the branches of the hepatic artery and portal vein to the liver Liver lobule

Hexagonal pattern of lobes Has a central vein running through its center from which sinusoids (large capillaries) and plates of hepatocytes (liver cells) radiate toward and imaginary perimeter extrapolated from surrounding interlobular portal triads Interlobular portal triads

Portal vein Hepatic artery Biliary duct Intrahepatic biliary ducts

Bile, a yellow-green secretion, for passage to the duodenum The hepatocytes secrete bile into the bile canaliculi formed between them The canaliculi drain into the small interlobular biliary ducts Then into large collecting bile ducts of the intrahepatic portal triad Bile ducts of the intrahepatic portal triad merges to form the right and left hepatic ducts Extrahepatic bile ducts

The right and left hepatic ducts drain the right and left lobes of the liver The right and left hepatic ducts unite to form the , shortly after leaving the porta hepatis Common hepatic duct is joined on the right side by the to form the common bile duct The bile duct conveys the bile to the descending part of the duodenum The common bile duct Forms in the free edge of the lesser omentum The length varies from 5 to 15 cm, depending on where the cystic duct joins the common hepatic duct Descendens posterior to the first part of duodenum Lies in a groove on the posterior surface of the head of the pancreas On the left side of the descending part of duodenum comes into contact with the main pancreatic duct The hepatopancreatic ampulla (ampulla of Vater)

Is formed by the union of the main pancreatic duct and common bile duct Is the dilation within the major duodenal papilla The circular muscle around the distal end of the bile duct is thickened to form the sphincter of the bile duct When sphincter contracts bile cannot enter the ampulla and the duodenum Bile backs up to the gallbladder for concentration and storage Jaundice (icterus)

Yellow staining of most body tissues, skin, mucous membranes and conjunctiva by circulating bile pigments Increased level of bilirubin Result of liver or pancreatic diseases, gallstones, haemolytic anaemias The gallbladder

Lies in the gallbladder fossa on the visceral surface of the liver The pear shaped, has a capacity of up to 50 ml of bile Has three parts: the fundus, the body and the neck Peritoneum completely surrounds the fundus and binds its body and neck to the liver The fundus of gallblader

The wide end of gallbladder Projects from the inferior border of the liver Located at the tip of the right 9th costal cartilage in the midclavicular line The place of intersection of the right costal margin with the lateral border of the rectus abdominis muscle (4-5cm from the anterior median line to the right) The body of the gallbladder

Contacts the visceral surface of the liver, the transverse colon, the superior part of duodenum The neck of gallbladder

Makes an S-shaped bend Joins the cystic duct Narrow, tapered and directed toward the porta hepatis The mucosa of its spirals into a fold – the spiral valve – keeps the cystic duct open The cystic duct

Approximately 4 cm long Connects the neck of the gallbladder to the common hepatic duct Passes between the layers of the lesser omentum Usually parallel to the common hepatic duct, which joins to form the common bile duct Blood supply of gallbladder and cystic duct The from the right hepatic artery in the angle between the common hepatic duct and cystic duct and visceral surface of the liver (cystohepatic triangle of Calot) The cystic veins enter the liver directly or drain through the portal vein The veins from fundus and body pass directly into the visceral surface of the liver and drain into the hepatic sinusoids Innervation of the gallbladder and cystic duct

Nerves pass along the cystic artery from the celiac plexus and from the right phrenic nerve (somatic afferent fibers) Parasympathetic stimulation causes contractions of the gallbladder and relaxation of the sphincters at the hepatopancreatic ampulla Stimulated by the hormone cholecystokinin produced by the duodenal wall in response to a fatty meal

Spleen

The largest lymphatic organ Participates in the body’s defence system as a site of lymphocyte proliferation Identify, removes and destroy expanded red blood cells Brokes-down platelets Is involved in recycling iron and globin Blood reservoir Spleen Approximately 12 cm long and 7 cm wide A purplish color The most vulnerable abdominal organ Normally contains a large quantity of blood The superior border is sharp and often notched whereas inferior is rounded Posterior (medial end) and anterior extremity Spleen

Mobile organ

Intraperitoneal

Entirely surronded by peritoneum except at the hilum Spleen

Normally does not descend inferior to the left costal (rib) margin

It rests on the left colic flexure Spleen

Lies superficially in the left hypochondriac region between the 9th through 11th ribs and is separated from them by the diaphragm and the costodiaphragmatic recess In the recumbent position the long axis of its roughly parallel to the long axis of the 10th rib The hilum of the spleen

Is often in contact with the tail of the pancreas

Constitutes the left boundary of the omental bursa The relations of the spleen

Anteriorly – the stomach Posteriorly – the left part of the diaphragm Inferiorly – the left colic flexure Medially – the left kidney The relations of the spleen The of the spleen

The conects the spleen and the greater curvature of the stomach

The splenorenal ligament conects the spleen and the left kidney

Contain splenic vessels

Attached to the hilum of the spleen on its medial aspect The capsule of the spleen

Thin, composed of dense, irregular fibroelastic connective tissue, containing occasional smooth muscle cells

Thickened at the hilum

The trabeculae (internally) arising from the deep aspect of the capsule, carry blood vessels to and from the soft parenchyma or splenic „pulp” (the substance of the spleen)

The smooth muscle and trabeculae periodically expelled a blood into the circulation The splenic artery The largest branch of the celiac trunk Follows a tortuous course posterior to the omental bursa, anterior to the left kidney and along the superior border of the pancreas Between layers of splenorenal ligament divides into five or more branches that enter the hilum Between layers of gastrosplenic ligament divides into short gastric arteries The splenic vein Is formed by several tributaries that emerge from the hilum

It is joined by the inferior mesenteric vein and runs posterior to the body and tail of the pancreas throughtout most of its course

Unites with the superior mesenteric vein posterior to the neck of the pancreas to form the portal vein The splenic lymphatic vessels

Leave the splenic nodes in the hilum and pass along the splenic vessels to the pancreaticosplenic lymph nodes

These nodes relate to the posterior surface and superior border of the pancreas The nerves of the spleen

Derive from the celiac plexus THANK YOU !!!