Physical Sciences 19 Flashcards
what happens to glucose not used immediately?
stored in the liver as glycogen
Glycogen uptake mechanism for liver (insulin function)
inactivates liver phosphorylase
activates glucokinase
enhances uptake of glucose from blood
increases of glycogenesis enzymes (for glycogen storage)
what is the most important functional roles of insulin
controls from moment to moment whether fat (decrease insulin) or carbohydrates (increase insulin) will be used for energy by the cells
what hormone lowers blood glucose levels
insulin
vascular supply of the liver
high blood flow and low vascular resistance
why is it important that the liver has low vascular resistance
it is a storage site for lots of blood (about 25%)
what is the pressure into the liver?
9 mm Hg
what is the pressure from liver to vena cava?
0 mm Hg
effects of cirrhosis on blood flow
increases blood resistance to blood flow
this is because it causes fibrosis of liver
effect of clot blocking the portal vein
blockage of return blood from spleen and intestines
increases capillary pressure in the intestinal wall (loses fluid from capillaries to intestinal system –> death)
what is the pressure differential in the liver vascular system
9 mm Hg
hepatic sinusoids are highly permeable to ___
proteins
protein concentration similar to plasma (6 g/dL)
what is ascites?
swelling of the abdomen due to large amount of fluid in abdominal cavity
caused by higher than normal pressure in hepatic veins
mechanism of ascites
higher pressure in hepatic veins (i.e. from right atrium)
back pressure forces fluid into lyme
fluid leaks into the abdominal cavity
function of bile
emulsify fats in the liver
what produces bile? where is it stored? secreted by?
produced and secreted by liver
stored and concentrated in gall bladder
components of Bile
bile acid
water and electrolytes
cholesterol and phospholipids (lecithin)
pigment
pigment of bile due to
bilirubin
bile acids
cholic and chenodeoxycholic acids via HEPATOCYTES
deoxycholic and lithocholic acid (via BACTERIA)
bilirubin cycle
- RBCs are destroyed by reticuloendothelial system – heme release
- hemoglobin is phagocytized, split into heme and globin
- heme goes into blood where it is converted to biliverdin
- biliverdin converted to free bilirubin
- free bilirubin is transported in blood via albumin to liver
- liver conjugates bilirubin
- conjugated bilirubin is sent into the intestine or urine
transferrin
transportation of heme in blood
heme oxygenase
converts heme to biliverdin
first conversion during bilirubin formation
conversion of heme to biliverdin by heme oxygenase
conjugated bilirubin is:
secreted into the intestine
excreted in urine