Pancreas and Spleen Anatomy PDF

M.B.Ch.B. M.Sc. Ph.D. Anatomy 15/10/2024 1  Learning Objectives 1. Illustrate the structural foundation of Gall Bladder. 2. Describe the Biliary tree organization. 3. Demonstrate the structure of Pancreas. 4. Describe the anatomy and funct...

M.B.Ch.B. M.Sc. Ph.D. Anatomy 15/10/2024 1  Learning Objectives 1. Illustrate the structural foundation of Gall Bladder. 2. Describe the Biliary tree organization. 3. Demonstrate the structure of Pancreas. 4. Describe the anatomy and functions of Spleen. 5. Define the Portal Venous System. 6. List the Portosystemic Anastomosis. 15/10/2024 Email :[email protected] Website :http://Alkafeel.edu.iq 2  It is a pear-shaped sac lying on the visceral surface of the right lobe of the liver in a fossa between the right and quadrate lobes. It is divided into: a) Fundus b) Body c) Neck The gallbladder receives, concentrates, and stores bile from the liver. 15/10/2024 Email :[email protected] Website :http://Alkafeel.edu.iq 3  The peritoneum completely surrounds the fundus of the gallbladder and binds the body and neck to the visceral surface of the liver. Anteriorly related to the anterior abdominal wall and the inferior surface of the liver. Posteriorly related to the transverse colon and the first and second parts of the duodenum. Email :[email protected] Website :http://Alkafeel.edu.iq 4  The neck of gall bladder becomes continuous with the cystic duct, which turns into the lesser omentum to join the common hepatic duct, to form the common bile duct. Common bile duct is about 8 cm long lies in the right free margin of the lesser omentum in front of the opening into the lesser sac. Email :[email protected] Website :http://Alkafeel.edu.iq 5  It ends below by piercing the medial wall of the second part of the duodenum about halfway down its length. It is usually joined by the main pancreatic duct, and together they open into a small ampulla in the duodenal wall, called the hepatopancreatic ampulla (ampulla of Vater). The terminal parts of both ducts and the ampulla are surrounded by circular muscle, known as the sphincter of the hepatopancreatic ampulla (sphincter of Oddi). Email :[email protected] Website :http://Alkafeel.edu.iq 6  The cystic artery, a branch of the right hepatic artery, supplies the gallbladder. The cystic vein drains directly into the portal vein. The lymph drains into a cystic lymph node situated near the neck of the gallbladder. From here, the lymph vessels pass to the hepatic nodes along the course of the hepatic artery and then to the celiac nodes. Email :[email protected] Website :http://Alkafeel.edu.iq 7  Sympathetic and parasympathetic vagal fibers form the celiac plexus. The gallbladder contracts in response to the hormone cholecystokinin, which is produced by the mucous membrane of the duodenum on the arrival of fatty food from the stomach. Email :[email protected] Website :http://Alkafeel.edu.iq 8  The pancreas is both an exocrine and an endocrine gland. The exocrine portion of the gland produces a secretion that contains enzymes capable of hydrolyzing proteins, fats, and carbohydrates. The endocrine portion of the gland, the pancreatic islets (islets of Langerhans), produces the hormones insulin and glucagon, which play a key role in carbohydrate metabolism. Email :[email protected] Website :http://Alkafeel.edu.iq 9  The pancreas lies mostly posterior to the stomach. It extends across the posterior abdominal wall from the duodenum, on the right, to the spleen, on the left. The pancreas is retroperitoneal except for a small part of its tail, and consists of a head, uncinate process, neck, body, and tail: Head of pancreas lies within the C-shaped concavity of the duodenum Uncinate Process projecting from the lower part of the head Email :[email protected] Website :http://Alkafeel.edu.iq 10  Neck of pancreas is anterior to the superior mesenteric vessels. Tail of pancreas ends as it passes between layers of the splenorenal ligament. The pancreatic duct begins in the tail of the pancreas, passes to the right through the body of the pancreas and, after entering the head of the pancreas, turns inferiorly. In the lower part of the head of pancreas, the pancreatic duct joins the bile duct. Email :[email protected] Website :http://Alkafeel.edu.iq 11  Pancreas has two ducts; main and accessory. The main duct joins the CBD forming the hepatopancreatic ampulla (ampulla of Vater), which enters the descending part of the duodenum at the major duodenal papilla. The accessory pancreatic duct empties into the duodenum just above the major duodenal papilla at the minor duodenal papilla. The main and accessory pancreatic ducts usually communicate with each other. Email :[email protected] Website :http://Alkafeel.edu.iq 12  The splenic and the superior and inferior pancreaticoduodenal arteries supply the pancreas. The corresponding veins drain into the portal system. Lymph nodes are situated along the arteries that supply the gland. The efferent vessels drain into the celiac and superior mesenteric lymph nodes. Email :[email protected] Website :http://Alkafeel.edu.iq 13  The spleen is the largest single mass of lymphoid tissue in the body, develops as part of the vascular system in the part of the dorsal mesentery that suspends the developing stomach from the body wall. It is red, oval shaped and has a notched anterior border. It lies just beneath the left half of the diaphragm close to the 9th, 10th, and 11th ribs. Its lower pole extends forward only as far as the mid-axillary line and cannot be palpated on clinical examination. Email :[email protected] Website :http://Alkafeel.edu.iq 14  The spleen is surrounded by peritoneum, and it is connected to: 1. Greater curvature of the stomach by the gastrosplenic ligament, which contains the short gastric and gastro- omental vessels. 2. Left kidney by the splenorenal ligament, which contains the splenic vessels and tail of pancreas. Both these ligaments are parts of the greater omentum. Email :[email protected] Website :http://Alkafeel.edu.iq 15  The spleen is surrounded by visceral peritoneum except in the area of the hilum on the medial surface of the spleen. The splenic hilum is the entry point for the splenic vessels and the tail of the pancreas reaches this area. Email :[email protected] Website :http://Alkafeel.edu.iq 16  Anteriorly: The stomach, tail of the pancreas, and left colic flexure. The left kidney lies along its medial border. Posteriorly: The diaphragm; left pleura (left costodiaphragmatic recess); left lung; and 9th, 10th, and 11th ribs. Email :[email protected] Website :http://Alkafeel.edu.iq 17  The splenic artery is the largest branch of the celiac artery. It has a tortuous course as it runs along the upper border of the pancreas. The splenic vein leaves the hilum and runs behind the tail and the body of the pancreas. Behind the neck of the pancreas, the splenic vein joins the superior mesenteric vein to form the portal vein. Email :[email protected] Website :http://Alkafeel.edu.iq 18  The lymph vessels emerge from the hilum and pass through a few lymph nodes along the course of the splenic artery and then drain into the celiac nodes. Email :[email protected] Website :http://Alkafeel.edu.iq 19 1. Mechanical filtration of red blood cells. 2. Active immune response. 3. Produces all types of blood cells during fetal life. 4. Storage of red blood cells, lymphocytes and other formed elements. Email :[email protected] Website :http://Alkafeel.edu.iq 20  Portal Venous System The portal vein is the final common pathway for the transport of venous blood from the abdominal part of GIT, spleen, pancreas, and gallbladder. It is about 2 in. (5 cm) long, formed by the union of the splenic vein and the superior mesenteric vein posterior to the neck of the pancreas at the level of vertebra L2. Email :[email protected] Website :http://Alkafeel.edu.iq 21  Portal Venous System The vein ascends toward the liver, passes behind the first part of duodenum and enters the right margin of lesser omentum. It is anterior to the omental foramen and posterior to both the bile duct and the hepatic artery proper. Email :[email protected] Website :http://Alkafeel.edu.iq 22  Portal Vein It enters the liver after dividing into right and left branches. Tributaries: 1. Splenic vein 2. Left gastric vein 3. Right gastric vein 4. Cystic vein 5. Inferior mesenteric vein 6. Superior mesenteric vein Email :[email protected] Website :http://Alkafeel.edu.iq 23  Portosystemic Anastomosis It is a specific type of anastomosis that occurs between the veins of the portal circulation and those of the systemic circulation. 100% of the portal venous blood flow can be received from the hepatic veins, while in patients with elevated portal vein pressure (e.g. due to cirrhosis), there is less blood flow to the liver. The rest of the blood enters collateral channels, which drain into the systemic circulation at specific points. Email :[email protected] Website :http://Alkafeel.edu.iq 24  Portosystemic Anastomosis These include: 1. Lower part of esophagus (left gastric and azygos). 2. Rectum (superior and inferior rectal) 3. Paraumbilical (paraumbilical and superficial epigastric) 4. Retroperitoneal (splenic and renal) 5. Intrahepatic (left branch of portal vein and IVC) Email :[email protected] Website :http://Alkafeel.edu.iq 25 Portosystemic Anastomosis Email :[email protected] Website :http://Alkafeel.edu.iq 26 Caput Medusae Email :[email protected] Website :http://Alkafeel.edu.iq 27 1. Gray’s Anatomy for Students. 2. Clinical Anatomy by Regions. Richard S. Snell. 3. Clinically Oriented Anatomy. Keith L. Moore. Email :[email protected] Website :http://Alkafeel.edu.iq 28