Lecture 25: Liver, Gallbladder, Pancreas, Spleen Flashcards
functions of the liver
- metabolism of carbohydrates, proteins and fat
- forms bile
- destroys old RBCs
- (fat soluble) vitamins and iron storage
what is bile needed for
the emulsification, absorption and digestion of fat
makes intestinal contents more alkaline
what produces and releases bile into the intercellular space of the liver
hepatocytes
what is contained in bile
detoxified waste, bile salts, cholesterol, phospholipids, bilirubin, electrolytes
what structure supplies ~25% of the liver’s blood supply
hepatic artery (and its branches)
what structure delivers blood drained from the abdominal digestive organs to the liver (~75% of liver’s blood supply)
the portal vein
what structure delivers bile from the liver and gallbladder to the duodenum
bile duct
what is the name for the portion of the lesser omentum that contains portal structures
hepatoduodenal ligament
where does the hepatic portal vein collect blood from
Gastroduodenal vein
Splenic vein
where does the gastroduodenal vein collect blood from
craniopancreatico-duodenal vein (left lobe of pancrease and duodenum)
right gastroepiploic vein (greater curvature of stomach)
where does the splenic vein collect blood from
left gastroepiploic vein (greater curvature of stomach)
pancreatics (right lobe of pancreas)
the liver drains to the caudal vena cava via what
the hepatic veins
functions of the gallbladder
- bile storage (from liver)
- concentration (removes water and electrolytes)
- release of bile into duodenum
- emulsification of fat
what is cholecystokinin and what is its function
it is released by the duodenum and jejunum
causes gallbladder to contract and causes sphincter of the hepatopancreatic ampulla (Oddi) to relax in order to release bile into the duodenum
what ducts drain into the bile duct
hepatic and cystic
what structure controls bile and pancreatic juice drainage
the sphincter of Oddi
what happens when the sphincter of the bile duct is contracted
prevents bile from entering the duodenum so instead it flows up the cystic duct to the gallbladder for concentration and storage
characteristics of the mucosa found within the gallbladder
simple columnar epithelium w/ short microvilli
characteristics of the muscularis externa found within the gallbladder
multiple smooth muscle layers for peristalsis to empty bile from the gallbladder
characteristics of the adventitia/serosa found within the gallbladder
dense CT adventitia anchors CT to the liver
serosa covers free surfaces
what happens to bile in equine since they have no gallbladder
a widened bile duct delivers bile directly to duodenum
bile flows constantly
2 glands of the pancreas
exocrine + endocrine
purpose of pancreatic exocrine gland
produces digestive juice that goes into duodenum
**secreted through pancreatic acini
juice has enzymes that break down protein, carbs, fat
purpose of pancreatic endocrine gland
pancreatic islets (scattered bw acini) serve as a source of insulin, glucagon and gastrin
what is the largest lymphoid organ
spleen!
functions of the spleen
- stores RBCs and platelets
- destroys old RBCs
- filters foreign particles, bacteria and phagocytic cells
- produces lymphocytes
what allows the spleen to contract and relax rhythmically
the presence of many smooth muscle fibers
what anastomosis present in pancreas blood flow?
anastomosis bw the celiac artery and cranial mesenteric artery
cranial + caudal pancreatico-duodenal
what indicates the transition bw foregut and midgut derivaties
pancreatico duodenal anastomosis
where does the spleen develop
in the dorsal mesogastrium
pulp that constitutes 75% of spleen volume and contains all formed elements of circulating blood
red pulp
what does red pulp contains
lots of macrophages in splenic cords
splenic sinuses that hemolyze damaged RBCs
what does white pulp contain
white pulp makes up a quarter of the body’s lymphocytes that attack antigens circulating in blood
