lecture 19-physiology of liver and pancreas Flashcards
what are sinusoids lined with
endothelial and kupffer cells
where is the space of disse found
between endothelial cells and hepatocytes
describe the blood flow and vascular resistance of the liver
high blood flow and low vascular resistance
what is the portal pressure into the liver
9 mm Hg
what is the pressure from the liver to the vena cava
0 mm Hg
what is the effect of cirrhosis on blood flow
increases blood resistance to blood flow
what are hepatic sinusoids highly permeable to
proteins
what is the protein concentration of the efferent lymph
6 g/dl
define ascites
large amount of fluid in abdominal cavity
what vitamins can the liver store
A, D and B12
what coagulation factors can the liver form
fibrinogen, prothrombin, accelerator globulin, factors VII, IX, X
what are phase 1 reactions in the liver catalyzed by
P-450 enzymes
what are phase 2 reactions in the liver doing
conjugating products from phase 1 reactions
what produces and secretes hepatic bile
liver
what acids are bile acids
cholic and chenodeoxycholic acids (synthesized by hepatocytes) and deoxycholic and lithocholic acid (converted by bacteria)
what is the major pigment in the bile
bilirubin
what is free bilirubin attached to when it is transported in the blood stream
plasma albumin
what are the possibly fates for conjugated bilirubin
secreted (active transport) into the intestine or excreted into urine
what are the common causes of jaundice
increased hemolysis, obstruction of bile ducts or damage to liver
what do alpha cells secrete
glucagon
what do beta cells secrete
insulin and amylin
what do delta cells secrete
somatostatin
what happens to unbound insulin
it is destroyed by the liver
describe the insulin receptor subunits
2 alpha (extracellular) and 2 beta (transmembrane) subunits
what autophosphorylates the beta subunits of the insulin receptor
tyrosine kinase
what does insulin inactivate in the liver
phosphorylase
what process does insulin inhibit
gluconeogenesis
what does beta oxidation result in
excess of acetyl-CoA
what do acetoacetic acids cause
acidosis
what are the major effects of glucagon
break down of liver glycogen and increased gluconeogenesis
what is the major factor that regulates glucagon secretion
blood glucose concentration
what does somatostatin inhibit
insulin, glucagon, and gastrin
what is type 1 diabetes due to
lack of insulin secretion
what occurs when there is injury to beta cells in type 1 diabetes mellitus
viral infections and autoimmune disorders
what is type 2 diabetes due to
insulin resistance
what is the major factor for type 2 diabetes
obesity
what is type 2 diabetes preceded by
metabolic syndrome
what are characteristics of metabolic syndrome
obesity, insulin resistance, fasting hyperglycemia, increased lipid triglycerides, decreased HDL levels, and hypertension
