What is in bile?
- bile salts
- bile pigments
- cholesterol
how many ways to get into and out of the liver? and what are they?
2 ways in ( absorption from GI TRACT, hepatic artery)
2 ways out (hepatic vein (blood), bile duct (getting rid))
IMPORTANT: what are the pathways of ingested glucose?
IMPORTANT: what are the pathways of ingested drugs?
what if you take drugs IV injection what is the pathway?
injected –> picked up in capillaries –> veins –> heart & lungs –> in arteriole blood–> enters liver. liver can assist to clear it.
what is bilirubin?
- in the blood
- filtered in the kidneys
- a lot will be eliminated in urine and feces
how does bilirubin move around body?
what is bilirubin responsible for
normal colour of urine
normal colour of feces
indicator of injury/ pathology
-> yellow phase of bruises
-> yellow pigmentation of jaundice
DIGESTION HAPPENS MOST WHERE?
SMALL INTESTINE
digestion occurs where?
mouth, stomach, small intestine
true or false? digestion and absorption are directly regulated
false not directly regulated , influenced by motility and secretion which are regulated by hormones, nervous system, local mechanisms
absorption in small intestine
- trying to cross epithial layer
- trying to cross apical membrane
- then enter epithelial cell
- get out of basolateral membrane
- enter intersitium
- picked up in capillary (heptaic portal system) or lymph (fats)
half our caloric intake is what? and mostly what?
carbs mostly starch
carbs can only be absorbed via a membrane transporter meaning?
we only have membrane transporters for MONOSACCHARIDES SOOO… we need to break down disaccharides (lactose, fructose) to monosaccharides to be able to be transported
artificial sweeteners (splenda)
- interact with sweet receptors
- but does not cross epithelium so does not add to caloric intake
disaccharides need what to make monosaccharides?
enzymes:
- lactase
- sucrase
- maltase
triglycerides is where ______
most of our fat calories come from
issues w/ triglycerides
- digestion complication, solubility issues
pancreatic lipases can act on triglycerides how?
in droplets and aided by colipase from pancreas
bile is produced where and stored where
produced liver
stored gall bladder
bile acids provide ______?
enzyme access
fat absorption pathway?
- large fat droplets from stomach enter
- bile salts coat each fat droplet now called emulsion
- enzyme action to create micelles
- if micelles come up close to apical surface of small intestine epithelial barrier
- monoglycerides and free fatty acids can diffuse pass the lipid bilayer into cell
- chylomicron formed intracellularly
- chylomicron secreted out and picked up in the lymph
- lymph dumps into circulator system (lacteal)
yes or no?
1. can we digest nucleic acid down to nucleotides?
2. can we transport nucleic acid
3. can we absorb nucleic acid
4. can we use nucleic acid
- yes
- yes
- yes
- yes
fat soluble vitamins follow what pathway of absorption?
fat pathway
