T1 L7 Anatomy of biliary tract & spleen Flashcards
What is the biliary course?
Depicts the travel of bile from intrahepatic ducts to entering duodenum
Right / left hepatic duct –> common hepatic duct
common hepatic duct + cystic duct–> common bile duct
Common bile duct + pancreatic duct –> duodenum
What is the intrahepatic bile duct?
Runs parallel to portal vein & hepatic artery
Smaller bile ducts have a much thinner wall & cuboidal epithelium
Larger bile ducts have loose connective tissue & a single layer of columnar epithelium
What is the extra hepatic bile duct?
7cms
Runs in free edge of lesser omentum
Joined by cystic duct near portal hepatis
Meets with right end of pancreatic duct - ampulla Vater
Enters 2nd part of duodenum at sphincter of Oddi
Lumen has highly columnar epithelium
Blood - cystic vessels from coeliac & into porta
What is the duct wall like in the extra hepatic bile duct?
Dense fibrous connective tissue & smooth muscle cells
Describe the location of the gallbladder
Lodged in a fossa on the visceral surface of the right lobe of the liver
Between inferior border of liver & duodenum
Describe the anatomy of the gallbladder
Conical, pear shaped
10cm length, 3cm diameter
Held by peritoneum which forms outer wall
Divided into fundus, body & neck
Describe the wall of the gallbladder
Simple columnar epithelium & smooth muscle
What are the functions of the gallbladder?
Concentrate & store bile
Selectively absorb bile salts
Excrete cholesterol
Excrete mucous
Describe the mechanism of the gallbladder
1) Contraction / emptying of stomach
2) Fatty foods in duodenum
3) Cholecystokinin release
4) Sphincter of Oddi relaxed
5) Emulsification of fat
Why do gallstones occur?
Physical changes in bile
Low bile salts
Excessive cholesterol
Describe the complications of gallstones
Partially or fully obstruct flow of bile
Biliary colic - crampy, right upper abdominal pain that comes & goes repeatedly
Acute cholecystitis - inflammation of gall bladder than causes pain on right upper quadrant
Describe visceral pain in context of the gallbladder
Most visceral pain signals from organ within abdomens are carried alongside sympathetic fibres
Abdominopelvic splanchnic nerves contain 2-way nerve transmission from viscera within abdominal cavity
Pain sensation from foregut organs passes via coeliac ganglion
Describe the anatomy of the pancreas
Comma shaped
12cm x 3cm
Divided into head, body & tail
How can the head of the pancreas be identified?
It is lobular compared to the duodenum which is smooth
What is the pathway of pancreatic secretions?
Exocrine secretions collected into small ducts. These unite to form pancreatic duct (Wirsung)
Duct of Wirsung joins with common bile duct to become hepatopancreatic ampulla
Ampulla of Vader enters duodenum post anal sphincter
Secondary duct of Santorini enters duodenum 2cm superior to major duodenal papilla
Where is the pancreas located?
Head is at the level of the descending duodenum - just below L1
Body is behind stomach & extends towards spleen
What arteries supply the pancreas?
Pancreatic - branches from the coeliac
Join to form an arc (gastroduodenal & pancreaticoduodenal)
What veins supply the pancreas?
Portal which is originally from the splenic & superior mesenteric
What nerves supply the pancreas?
Coeliac ganglia & vagus
What is the histology of the pancreas?
Exocrine & endocrine gland
Exocrine portion has cluster of acini cells - pyramidal epithelium. Secrete digestive enzymes
Endocrine portion has cluster of centroacinar cells - cuboidal epithelium. Secretes hormones e.g. insulin
What diseases are associated with the pancreas?
Inflammation - pancreatitis
From gallstones, heavy alcohol intake, cystic fibrosis, high levels of calcium or blood fats
What factors increase the risk of pancreatic cancer?
Obstructive jaundice
Heavy alcohol intake
Smoking
Genetics
What is the spleen?
Part of lymphatic system
Where is the spleen
Underneath 9th, 10th, 11th rib on left hand side
At left hypochondriac region
Describe the anatomy of the spleen
12cm in length
Oval shape
Outer suface has indentations from neighbouring organs - stomach, left kidney, left flexure of colon
Parenchyma contains lymphatic tissue & blood vessels
What is the VAN of the spleen?
Splenic artery
Splenic vein
Splenic plexus
What is the function of the spleen?
Parenchyma has 2 pulps: red & white
Red pulp - blood filled venous sinuses
White pulp - lymphatic tissue. Immune, removal of macrophages, storage of platelets, production of blood cells
