GI 2 Flashcards
these are specialized folds in the small intestine that contain blood vessels and lacteals
villi
these increase surface area even more by forming the brush border
microvilli
this is the microenvironment for enzyme release and digestion/ absorption
brush border
what is one major function of the liver?
bile production
function of bile
makes fats soluble
the liver produces _______ from heme breakdown
bilirubin
what structure stores and concentrates bile?
gallbladder
what stimulates bile release from the gallbladder?
CCK and vagus nerve
what stimulates the release of CCK?
lipids in the duodenum
what are the main components of bile?
bile salts
phospholipids
cholesterol
bile pigments
this component of bile emulsifies fats
bile salts
insoluble bilirubin is bound to _______ in the blood
albumin
bilirubin is conjugated to what in the liver?
glucoronic acid
conjugated bilirubin is broken down into what 2 things in the small intestine?
urobilin- urine
stercobilin- stool
this results from abnormally high accumulation of bilirubin the blood
jaundice
indirect bilirubin is ___________
unconjugated
direct bilirubin is ____________
conjugated
bile acids are made from ______
cholesterol
bile acids are conjugated with what to their final bile salt structure?
glycine
taurine
(amino acids)
bile salts are _________, which allows them to act as emulsifiers
amphiphathic
what transports bile back into the portal system?
Na+/ bile cotransporter
where is bile reabsorbed?
ileum
after fat is emulsified, what breaks it down into micelles?
pancreatic lipase and colipase
after absorption, lipids are ________
reassembled
lipids enter the lacteals as a _______
chylomicron
triglyceride digestion results in…..
monoglycerides and free fatty acids
cholesterol digestion results in…..
ester digestion to cholesterol and fatty acid
phospholipid digestion results in…
lysolecithin and fatty acid
these have low cholesterol levels and carry cholesterol and triglycerides to adipose tissue
VLDLs
these are the main carrier of cholesterol and drop it off to “needy” cells
LDLs
these remove excess cholesterol from cells and vascular membranes
HDLs
what organs does the liver receive blood from?
spleen
stomach
pancreas
small intestine
colon
where do blood from the hepatic artery and portal vein mix?
sinusoids
bile in the liver is released into bile ________
canaliculi
phase 1 drug metabolism in the liver includes….
CYP450 enzyme breakdown
phase 2 drug metabolism in the liver includes…
making the substance more water soluble
sugars must be absorbed as _______
monosaccharides
how are fat soluble vitamins (A, D, E, K) absorbed?
just like dietary lipids
cecal distention causes the ileocecal valve to __________
constrict
are enzymes secreted in the large intestine?
no
what does the large intestine secrete?
mucus
