9.18.13 Kin 110 lecture notes- Starch digested by amylase to glucose (simple sugars)o Salivary amylase broken down in the stomacho The one in the pancreas and saliva are identical twins- Protein digested to amino acidso Use series of enzymes (pepsin, etc.)- Lipases break bonds in triglycerides too triglyceride and fatty acidso triglyceride – storage form of fat 3 fatty acids attached to a glycerol- Point of absorbtion:o Passage of nutrients OUT of the GI system and intoo Nutrients: simple sugarso Nutrients in blood stream go into body cells- Small intestineo First 18 in. = duodenum Where most digestion is taking placeo Next 4-5 ft = jejunum Absorption takes place- To enhance absorption, maximum surface area.- Inside surface of the jejunum modified 3 ways to maximize surface areao 1. Folds looks like rolling hillso 2. Villi absorb nutrients from the jejunum increase absorption area by 10xo 3. Microvilli projections that increase surface area by 20x hedgehog spikes- fold, villi, and microvilli increase absorption area by 3x10x20=600 times!o 250 square meters of absorptive area of jejunumo area for reference: tennis court- transport proteins on membrane of small intestine absorb nutrients:o simple sugars from starcho amino acids from proteino fatty acids from triglycerideso all absorbed by transport proteins ^^^- nutrients from diet absorbed by intestinal cellso transported outo leaving intestine; different paths for water soluble vs. fat soluble nutrients- summary so far:o digestion occurs in the mouth, stomach, duodenumo starch (CHO), triglycerides (fat), and PRO digested to simple sugars, fatty acids and glycerol, and amino acidso products absorbed by villi- symptoms of stomach acid deficiency?o (hypochlorhydia)o protein & digestion is an issue- not enough bicarbonate?o Related to stomach acido Released by pancreaso It neutralizes stomach acido Heart burn/similar symptoms except lower downo Acid reflex in small intestine- Celiac disease?o Gluten: protein commonly found in grains (rye, wheat, barley)o Grains without gluten: wild rice, corn, quinoa, oatso Dietary change can improve symptoms- Sugars and amino acidso Intestines then Go to portal veino The portal vein goes to the livero Then?o Sugar and amino acids then go to the rest of the blood streamo hearto rest of the bodyo in the liver… does things with aminos, simple sugars… makes modifications pulls things out, “edits” the nutrients before circulation critical in many situations- fat-soluble molecules like fatty acids, cholesterol packaged into chylomicrons too big for capillarieso Go to lymph and moveo Slowly to the heart rest of bodyo Do not pass through the liver first- Alcohol very toxic to all body cells but especially nerve cells (brain)o Liver metabolizes most before it causes trouble.o Excess alcohol use short-term (1 time)? braino Long term (years)? Liver is affectedo You adapt to consuming alcohol…- Drinking too much alcohol causes (fatty liver disease,
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