Liver A&P

glycogenesis

liver stores excess glucose as glycogen

glycoNEOlysis

liver breaks down glycogen into glucose when blood sugar drops

gluconeogenesis

liver makes NEW glucose from protein and fat when glycogen is gone

the liver

stores glucose, releases glucose, and makes new glucose

the liver is

the largest internal organ and gland in the body

located in RUQ

hepatocytes

functional cells of the liver, are capable of regeneration

Kupffer cells

remove bacteria in portal venous blood

hepatic artery

oxygenated blood from system circulation

hepatic portal vein

nutrient rich blood from the GI tract

how much percentage of blood comes from the portal vein

75%, rest is from the hepatic artery

how much percent of CO is received

25%

hematological liver functions

• blood storage and filtration

• synthesis of thrombopoietin and clotting factors

• synthesis of albumin

metabolic liver functions

• deamination (converting ammonia to urea, then excreted in urine by kidneys)

• carb and fat metabolism

• bile production

endocrine and regulatory functions of the liver

• synthesis of angiotensin

• regulates nitric oxide

• detoxification

immune functions of the liver

• kupffer cells activity

• filtration of bacteria from portal blood

blood liver storage

• 200-400mL of blood

• stores vitamin A, D, E, K

• stores iron

hepatocytes produces roughly 90% of what in the liver

thrombopoietin

stimulates bone marrow to produce platelets

prothrombin (factor II)

• requires vitamin K for activation

• converted to thrombin, which converts fibrinogen to fibrin

fibrinogen (factor I)

• plasma made by the liver

• activated by thrombin to form fibrin clot mesh

liver pts don’t clot because

they don’t make CLOTTING FACTORS

not because low plts only

albumin

• maintain oncotic pressure

• transports hormones, calcium, some meds

• keeps fluids in the vessels, sick liver can make albumin, fluids leaks out, ascites and edema

deamination

when the liver breaks down ammonia

• detoxifies it into urea, kidneys excrete it into urine

bilirubin is

byproduct of old RBC breakdown

the liver conjugates bilirubin (makes it water soluble) and

secretes it into bile

bile is stored in

the gallbladder

in the intestine bilirubin is made into

urobilinogen

• some goes to kidneys and makes urine yellow (becomes urobilin)

• most of it converted to stercobilin, in the colon makes poop BROWN

what does bile do

emulsifies fats, allow lipase to digest and absorb dietary fat

if bile doesn’t reach the intestine

stole becomes pale and bilirubin backs up causing

JAUNDICE AND DARK URINE

nitric oxide function

keeps blood vessels slightly relaxed and prevents excess vasoconstriction

the liver keeps nitric oxide balanced by

• breaking down excess NO

• removes gut derived substances that stimulates its production

• keep the abdominal blood vessels at a normal tone

if the liver is damaged the splanchnic (Abd) blood vessels overproduce nitric oxide and

massive vasodilation occurs, casing low BP and decreases afterload

immune functions of the liver

• kupffer cells filter bacteria, toxins and antigens from portal venous blood

• produces proteins for innate immunity

• helps clear antibodies and immune complexes

• serves as a surveillance organ, for anything absorbed throughput the GI tract

everything absorbed from the gut through the liver fist, so the liver acts like a giant immune filter

when it fails, bacteria slips through