4 Duodenum Shortest (25cm) part of the small intestine. Joins the stomach to the jejunum.Pursues a C–shaped course around the head of pancreas.Begins at the pylorus on the right side L1.Ends at the duodenojejunal junction on the left (L2).A retroperitoneal structure except 1st inch.Receives the opening of bile & pancreatic duct.
5 Parts of the Duodenum Divided into four parts 1. Sup. (1st part) 5cm--Lies ant. to the body of the L1.2. Descending (2nd part) 7-10cm descends along the side of the L1 – L3.3. Horizontal (3rd part) 6-8cm--crosses the L3.4. Ascending (4th part) 5cm --begins at left of L3 & rises as for as the upper border of L2
6 First PartBegins at the pylorus & runs upward & backward of the 1st lumbar vertebraRelationAnteriorlyQuadrate lobe of theliver & Gall bladderPosteriorlyLesser sac (1st inch only) gastroduodenal artery, bile duct, & IVCSuperiorlyEpiploic foramenInferiorlyHead of pancreas
7 Second PartRuns vertically downward in front of the hilum of the right kidney on the right side of the L2 & L3.At posteromedial border, bile & main pancreatic ducts open.The two ducts unite to form the ampulla that opens on the summit of the Major duodenal papillaopening of accessory pancreatic ducts little higher than the Major papilla Minor duodenal papilla
8 Relation of the 2nd part Anteriorly Fundus of the gall bladder, right lobe of liver, transverse colon, & coils of the small intestinePosteriorlyHilum of the right kidney & right ureterLaterallyAscending colon, right colic flexure& right lobe of liverMediallyHead of pancreas, the bile & min pancreatic ducts
9 Third PartRuns horizontally to the left on the subcostal plain, passing the vertebral column in front of L3 following the lower margin of pancreasRelationAnteriorlyMesentery of smallintestine, SMA, SMV,coils of jejunumPosteriorlyRight ureter, right psoas muscle, IVC & aortaSuperiorlyHead of pancreasInferiorlyCoils of jejunum
10 Fourth PartRuns upward along the left side of the aorta & curves ant to join jejunum forms an acute angle duodenojejunal flexure The flexure is held in position by a peritoneal fold theligament of Treitz which is attached to the right curse of the diaphragm, fixes the terminal part of the duodenum and prevents it from moving inferiorly
11 Relation Anteriorly Root mesentery & coils of jejunum Posteriorly Left margin of aorta & medial border of left psoas
12 Mucous Membrane and Duodenal Papillae Mucus membrane is thick.In the first part of the duodenum it is smooth. In the remainder of the duodenum it is thrown into numerous circular folds called the plicae circularis
13 ArteriesThe upper half is supplied by the sup pancreaticoduodenal artery br of gastroduodenal artery. The lower half is supplied by the inf pancreaticoduodenal artery br of SMAVeinsSup pancreaticoduodenal artery into portal & inf pancreaticoduodenal drains into SMA
14 Nerve Supply Sympathetic & parasympathetic (vagus) nerves from celiac & superior mesenteric plexuses
15 Clinical Notes Trauma to the duodenum In severe injury to ant abdominal wall, the 3rd partMay be severely crushed against the L3Duodenal UlcerAn ant ulcer of the 1st inch of 1st part may perforate into greater sac and the fluid my go to the right iliac fossa. In this case the differential diagnoses b/w a perforated duodenal ulcer & perforated appendix may be difficultDuodenal RecessesClose to the duodenojejunal junction, there may be four small pocketlike pouches of peritoneum called the superior duodenal, inferior duodenal, paraduodenal and retroduodenal recessesImportant Duodenal RelationGallstone may ulcerate the duodenum
18 PancreasTailHeadNeckBodyLocationThe pancreas is both an exocrine and an endocrine gland. Lies in epigastrium & left upper quadrant.Soft & lobulated situated on the post abdominal wallIs a retroperitoneal structureCrosses the transpyloric plainDivided into four partsHead, Neck, Body & Tail
19 Pancreas Head of the pancreas Is disc shaped lies within the concavity of duodenumA part from head extends to the left behind the SMA is called UNCINATE PROCESSNeck of the pancreasConstricted portion of pancreas connects head to the bodyBody of the pancreasRuns upward & to the left across the midlineTail of the pancreasPasses forward in the splenicorenal ligament & comes in contact with the hilum of the spleen
21 Relation of the pancreas Anteriorly from right to leftTransverse colon, transverse mesocolon, lesser sac & stomachPosteriorly from right to leftBile duct, portal & splenic veins, IVF, aorta, origin of SMA, left psoas muscle, left suprarenal gland, left kidney, & hilum of the spleen
23 Pancreatic DuctsThe main pancreatic duct begins in the tail and runs the length of the gland, receiving numerous tributaries on its way. It opens into the 2nd part of the duodenum at about its middle with the bile duct on the major duodenal papilla. Sometimes the main duct drains separately into the duodenum.The accessory pancreatic duct if present, drains the upper part of the head, opens into the duodenum a short distance above the main duct on the minor duedenal pappila. The accessory duct frequently communicates with the main duct.
24 Blood SupplyArteriesThe splenic and the superior and inferior pancreaticoduodenal arteries supply the pancreas.VeinsThe corresponding veins drain into the portal system.Lymph DrainageLymph nodes are situated along the arteries that supply the gland. The efferent vessels ultimately drain into the celiac and superior mesenteric lymph nodes.Nerve SupplySympathetic and parasympathetic (vagal) nerve fibers supply the area.
25 Diagnosis of Pancreatic Disease The deep location of the pancreas sometimes gives rise to problem of diagnosis for the following reasonsPain from the pancreas is commonly referred to the back.Because the pancreas lies behind the stomach and transverse colon, disease of the gland can be confused with that of the stomach or transverse colon.Inflammation of the pancreas can spread to the peritoneum forming the posterior wall of the lesser sac. This in turn can lead to adhesions and the closing off of the lesser sac to form a pseudocyst.