Anatomy of the biliary tract and spleen Flashcards
Gut associated organs
Liver
Spleen
Gall bladder
Pancreas
Bile
Secreted by hepatocytes into bile canaliculi
Biliary course
Depicts travel of bile from intrahepatic ducts to entering duodenum
Biliary tree
Sectoral ducts of right/ left liver
Right/ left hepatic duct
Common hepatic duct (cystic duct)
Common bile duct (pancreatic duct)
Duodenum
Intrahepatic bile duct
Runs parallel to portal vein and hepatic artery
Smaller bile ducts (ductules)- much thinner wall and cuboidal epithelium
Larger bile ducts have a loose connective tissue (flexible) and single layer of columnar epithelium
Extrahepatic bile duct
7cms
Runs in free edge lesser omentum
Joined by cytic duct near porta hepatis
Meets with right end of pancreatic duct0 ampulla vater
Enters 2nd part of duodenum at sphincter of oddi
Structure of exxtrahepatic bile duct
Duct wall- dense fibrous connective tissue
Wall also contains smooth muscle cells
Lumen- highly columnar epithelium
Blood: cystic vessels (from coeliac and into portal)
Gall bladder anatomy
Lodged in a fossa on the visceral surface, right lobe of liver
Between inferior border of liver (ant) and duodenum (post)
Conical, pear shaped
About 10cm in length and 3 in diameter
Held by peritoneum (forms outer wall)
Divided into fundus (lower aspect), body and neck
Wall: simple columnar epithelium, smooth muscle
Functions of gall bladder
Concentrate and store bile
Selectively absorb bile salts
Excrete cholesterol
Excrete mucous
Mechanisms
- Contraction/ emptying of stomach
- Fatty foods in duodenum
- Cholecystokinin release
- Sphincter of odd relaxed
- Emulsification of fat
Gall stones
Physical changes in bile e.g. low bile salts, excessive cholesterol
Stones can partially or fully obstruct flow of bile
Biliary colic
Gall stone blocks duct
Crampy right upper abdominal pain that comes and goes repeatedly
Acute cholecystitis
Inflammation gall bladder that also causes pain on right upper quadrant
Visceral pain
Most pain signals from organs within abdomen is carried alongside sympathetic fibres
Pancreas anatomy
Oblong in shape (comma shaped)
12-15cm long
3cm in width
Divided in (broad) head, (tapering) body and (sharp) tail
Exocrine secretions are collected into small ducts
Small ducts unit to form the pancreatic duct
Ducts of Wirsung joins common bile duct to become the hepatopancreatic ampulla
Ampulla of vater enters duodenum about 10cm post-pyloric sphincter
Secondary duct (of santori) enters duodenum about 2cm superior to major duodenal papilla
Pancreas location
Head at the level of the descending duodenum
Body behind stomach and extends towards spleen
Just below L1
Epigastric region
Pancreas arteries
Pancreatic, branches from the coeliac
Join forming an arc (gastroduodenal and pancreaticoduodenal)
Pancreas veins
Portal
originally from splenic and superior mesenteric
Pancreas nerves
Coeliac ganglia and vagus
Pancreas histology/ function
Both an exocrine and endocrine gland
Exocrine portion: clusters aka acini cells- pyramidal epithelium (98-99%)
Exocrine: secretion of digestive enzymes, the pancreatic juice
Endocrine portion: centreacinar cells aka islets of langerhans- cuboidal epithelium (1-2%)
Endocrine: secretion of hormones, e.g. insulin
Inflammation (pancreatitis)
Gallstones
Heavy alcohol intake
Cystic fibrosis
High levels of calcium of blood fats
Pancreatic cancer
Obstructive jaundice (gallstones)
Heavy alcohol intake
Smoking
Genetics
Spleen
Part of lymphatic system
Largest single mass of lymphoid tissue
Regarded as a blood gland
Underlies 9/10/11th rib on LHS
At the let hypochondriac region of the abdomen
Oval in shape
Spleen anatomy
12cm in length but can vary- age, disease
Outer surface shows indentations, caused by neighbouring organs (stomach, left kidney, left flexure of colon)
Parenchyma (inner part of spleen): contain the lymphatic tissue and blood vessels
Nerve supply: branches of coeliac nerve plexus
Spleen function
Parenchyma: two pulps- red and white
Red pulp: blood filled venous sinuses
White pulp: lymphatic tissue (lymphocytes, macrophages)
Functions:
- immune (like in lymph nodes)
- removal by macrophages of old blood cells
- storage of platelets
- production of blood cells (foetal life)
