abdomen_pancrease & extrahepatic biliary system

Pancreas

• A gland – Both exocrine and endocrine

• A retroperitoneal organ

• Like a thick upper end of a walking stick lying horizontally with the hook to the right side.

•At the level of L1 and L2.

•15-20 long•3cm wide•2cm thick

• Entire organ lies posterior to the stomach separated from it by lesser sac

• Divided into head, neck, body and tail.

• Head is moulded in the concavity of the duodenum

• Lies over the inferior vena cava and the, renal veins, right crus of the diaphragm and the bile duct.

• Uncinate process extends to the left and up from the posteroinferior boader of the head between the aorta and superior mesenteric vessles

Root of the transverse mesocolon along the whole length of the gland

Pnacreaticoduodin-al artery

• Neck is a narrow band just in front of the commencement of the portal vein.

• Bhind the pylorus

• Body is triangular in cross section

• Three boarders – Superior, Anterior and Inferior

• Three surfaces – Anterior, Inferior and posterior

• A projection from the superior surface slightly to the left of the neck, is known as the Tuber omentale

• Superior boarder – hepatic, coeliac and splenic arteris.

• Inferior boarder – Superior mesenteric artery

• Post. Surface – aorta with SMA, L.crus, L suprarenal and left kidney with vessels and splenic vein.

• Tail lies in the lienorenal ligament with the splenic vessels.

• Ducts – Main and accessory • Main opens in common with the bile duct at

hepatopancreatic ampulla (of Vater) 8-10 cm distal to the pylorus.

• Accessory opens 2cm proximally.• They communicate each other.

• Lymphatic – pancreaticosplenic, coeliac and superior mesenteric group of lymph nodes.

• Parasympathetic – Vagus - control secretion. (cholecytokinin-pancreozymin also contribute)

• Sympathetic – splanchnic - vasomotor.

• Endocrine – insulin deficiency – Diabetes

• Exocrine deficiency – digestive problems

• Carcinoma of the head common – can obstruct bile duct, portal vein, even pylorus

• Developmental anomalies – Annular pancreas– Accessory pancreatic tissue– Inversion of pancreatic ducts.

Extrahepatic Biliary Apparatus

• Right and left hepatic ducts

• Common hepatic duct

• Gall bladder

• Cystic duct

• Bile duct

• Right and left hepatic ducts arise from the right and left lobes of the liver

• Anterior most structures at the porta hepatis

• Surgically only the junction of the two lies outside the liver.

• Common hepatic duct is located in the free edge of the lesser omentum.

• Common hepatic duct = 3cm

• Joined by the cystic duct to form the bile duct

• Accessory hepatic ducts usually arise from the right lobe of the liver.

• Gall bladder – inferior surface of the liver extending into the anterior boarder

• 7-10cm long and 30-50ml capacity

• Divided into Fundus, body and neck

• Fundus projects between rectus abdominis and 9th costal cartilage

• Posteriorly over the beginning of the transverse colon

• Body lies on the fossa, in the inferior surface of the liver.

• Only the inferior surface is covered with the peritonium

• Mucus membrane of the neck is folded spirally to prevent the block

• Posteromedial wall of neck – Hartmann’s pouch

• Cystic vessels enter via loose areolar tissue in the upper part of the neck

3cm cystic duct

(8 cm)

• Bile duct pathway and relations are important

• Cystic artery – gall bladder and nearby ducts

• Post. Pancreaticoduodenal artery lower part of the bile duct

• Right hepatic artery – middle part of bile duct

• Accessory cystic from common hepatic artery or other branches may arise

• Venous blood from gall bladder– Directly to liver & joins hepatic veins– 1-2 cystic veins

• Constantly present lymph nodes– Cystic node– A node at the anterior border of the epiploic

foramen.

• Left and right vagi, right phrenic and sympathetic (T7-T9)

• As a result referred pain can occur at the stomach, right shoulder, right scapular

Clinical relevance

• Murphy’s sign

• Gall bladder investigation

• Cholelithiasis >biliary colic

• Cholecystectomy