14 Pancreatic Diseases Anatomy of the Pancreas Pancreas in Situ Parts and Landmarks • Head (includes uncinate process), neck, body, tail • Uncinate process lies behind superior mesenteric artery and anterior to aorta. • Neck overlies superior mesenteric artery and vein and portal vein. • Development Two endodermal gland buds of caudal foregut merge to form pancreas. Buds rotate with foregut. Dorsal bud forms body and tail. Ventral bud makes head; uncinate process rotates behind superior mesenteric artery. Original mesentery fuses with posterior peritoneum, and pancreas becomes retroperitoneal. Location and Locale of the Pancreas • Retroperitoneal and posterior to stomach: typically nonpalpable on physical examination • Neck of pancreas overlies L1 and L2 vertebral bodies in the transpyloric plane. • Head is to the right of and inferior to transpyloric plane. • Body and tail are to the left and above transpyloric plane. Duct System Main Pancreatic Duct • Begins in tail, runs medially into head • Turns inferiorly, closely related to bile duct • Ducts unite to form hepatopancreatic ampulla (of Vater). • Ampulla empties into descending duodenum at the major duodenal papilla. • Smooth muscle sphincter of pancreatic duct around terminal portion • Smooth muscle sphincter lies around terminal bile duct. • Hepatopancreatic sphincter (of Oddi) around hepatopancreatic ampulla Accessory Pancreatic Duct (Variable) • Can open into duodenum at minor duodenal papilla • Accessory duct more often joins main duct (~60%). • If main duct is small, and there is no juncture, accessory duct can carry majority of secretion. Functional Anatomy • Tubuloacinar gland structure with a variety of cell types, including intermingled islets of Langerhans • Parasympathetic and sympathetic nerves are distributed to islets and acini. • Cells’ secretions are controlled by endocrine and autonomic nervous activities. Exocrine Functions • Mediated by secretin and cholecystokinin formed by duodenal and jejunal epithelium • Acinar cells secrete amylase, lipase, trypsinogen, chymotrypsinogen, carboxypeptidase, and Cl−. • Ductal cells secrete HCO3−. • Some secretomotor input comes from vagal parasympathetic fibers. Endocrine Functions • Alpha cells secrete glucagon. • Beta cells (central islets) secrete insulin. Only gold members can continue reading. Log In or Register to continue You may also needBiliary DiseasesColon DiseasesLiver DiseasesHip and Thigh FracturesProstate DiseasesThyroid DiseasesGastroduodenal DiseasesEsophageal Diseases Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Google+ (Opens in new window)Like this:Like Loading... Related Tags: Netters Surgical Anatomy Review PRN Aug 12, 2016 | Posted by admin in ANATOMY | Comments Off on Pancreatic Diseases Full access? Get Clinical Tree
14 Pancreatic Diseases Anatomy of the Pancreas Pancreas in Situ Parts and Landmarks • Head (includes uncinate process), neck, body, tail • Uncinate process lies behind superior mesenteric artery and anterior to aorta. • Neck overlies superior mesenteric artery and vein and portal vein. • Development Two endodermal gland buds of caudal foregut merge to form pancreas. Buds rotate with foregut. Dorsal bud forms body and tail. Ventral bud makes head; uncinate process rotates behind superior mesenteric artery. Original mesentery fuses with posterior peritoneum, and pancreas becomes retroperitoneal. Location and Locale of the Pancreas • Retroperitoneal and posterior to stomach: typically nonpalpable on physical examination • Neck of pancreas overlies L1 and L2 vertebral bodies in the transpyloric plane. • Head is to the right of and inferior to transpyloric plane. • Body and tail are to the left and above transpyloric plane. Duct System Main Pancreatic Duct • Begins in tail, runs medially into head • Turns inferiorly, closely related to bile duct • Ducts unite to form hepatopancreatic ampulla (of Vater). • Ampulla empties into descending duodenum at the major duodenal papilla. • Smooth muscle sphincter of pancreatic duct around terminal portion • Smooth muscle sphincter lies around terminal bile duct. • Hepatopancreatic sphincter (of Oddi) around hepatopancreatic ampulla Accessory Pancreatic Duct (Variable) • Can open into duodenum at minor duodenal papilla • Accessory duct more often joins main duct (~60%). • If main duct is small, and there is no juncture, accessory duct can carry majority of secretion. Functional Anatomy • Tubuloacinar gland structure with a variety of cell types, including intermingled islets of Langerhans • Parasympathetic and sympathetic nerves are distributed to islets and acini. • Cells’ secretions are controlled by endocrine and autonomic nervous activities. Exocrine Functions • Mediated by secretin and cholecystokinin formed by duodenal and jejunal epithelium • Acinar cells secrete amylase, lipase, trypsinogen, chymotrypsinogen, carboxypeptidase, and Cl−. • Ductal cells secrete HCO3−. • Some secretomotor input comes from vagal parasympathetic fibers. Endocrine Functions • Alpha cells secrete glucagon. • Beta cells (central islets) secrete insulin. Only gold members can continue reading. Log In or Register to continue You may also needBiliary DiseasesColon DiseasesLiver DiseasesHip and Thigh FracturesProstate DiseasesThyroid DiseasesGastroduodenal DiseasesEsophageal Diseases Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Google+ (Opens in new window)Like this:Like Loading... Related Tags: Netters Surgical Anatomy Review PRN Aug 12, 2016 | Posted by admin in ANATOMY | Comments Off on Pancreatic Diseases Full access? Get Clinical Tree
