Physiology of the Hepatobiliary System Flashcards
Pain in GI tract
Almost exclusively from mechanoreceptors responding to contraction
With ulcers, damage to mucosa and submucosa permits H+ to reach muscularis externa…H+ leads to contraction of smooth muscle and sensation of pain
Structure of liver
Plates separated by isnusoids
Phagocytic Kupffer cells
Secretes bie into bile canaliculi that are drained by bile ducts
Carb fxn
Synthesis of proteins
Protein metab
Lipid metab
Storahge of blucose as glycogen
Release of glucose from glycogen
Syntehssi of new glucose
Albumins and blogulins
Amoonia to urea and synthesize of noness AA
Syntehsize VLDL, remove LDL, B-oxidatioin of fatty acids
Cholesterol metab
Storage site
Secreted and lost in bile
A,D, B12 and minerals like Fe
Bile choleresis
H2O and electrolytes
Bile salt dep from parenchymal cells
Independent from duct cells - hig in HCO3
Hepatic portal system
Products of digestion that are absorbed are delivered to liver
Caps drain into hepatic portal vein which carries blood to liver
Pressure in caps is higher than other series
Parenchymal secretions
Duct cell secretion
Active against the conc gradient….continusouly…bile fxns to emulsify lipids…inc by CCK
Duct - primarily HCO3 and H2O…meals, dyes, drug actively secreted by duct cells…stimulated by secretin to inc HCO3
Fiber
Reduce cholesterol by trappign a greater percentge of bile in bulkier and more fibrous feces
Gallbladder
Stores bile
Contraction of muscularis layer of gallbladder ejects bile into the common bile duct into duodenum
When small intestine is empty, sphincter of Oddi closes and bile is forced up cystic duct to gallbladerr
Secretin and CCK effects
Sec - duodenal low pH….stimulates HCO3 by pancreas and liver to secrete HCO3 to bile
CCK - in response to fat and protein content of chyme in duodenum…prod of pnacreatic enzymes…enhances secretin…stimulates contraction of gall bladder and relaxation of sphincter of Oddis
Bile production and secretion
Free bilirubin combines with glucuronic acid to form conjugated
Converted to urobilinogen by bacteria into intestines so it can be recycled
Most absorbed by ileum as sedcretion passes through
Deriv of cholesterol
Detox of blood
Excretion into the bile
Phago by Kupffer cells
Chem alteral of ammonia
Fed and fasted state
Fed - glycogeneiss and lipogenesis
Fasted - glycogenolysis and gluconeogenesis
PLasma proteins
Clotting factors 1,2,3,5,7,9,11
Albumin and globulin (excpet immunoglobulins) in liver
