X.DIGESTION The mechanical and breakdown of food into nutrients A.Digestive system: tube with accessory organs Tube Mouth : beginning Esophagus Stomach Small intestine Large intestine (colon) Rectum Anus: end B.Accessory organs Salivary glands Liver Gall bladder Pancreas C.Mouth Mechanical breakdown Chewing Chemical breakdown Saliva: Starch Mucin: binding and lubrication Swallowed food called bolus D.Stomach: expandable sac Stores and mixes Chemical digestion Movement of food to small intestine E.Chemical digestion Hydrochloric acid Enzymes Chyme: liquid mixture of food and gastric stomach fluid F.Small intestine: 20 feet long Digestion completed here Digestive enzymes act on: Carbohydrates Fats Proteins Nucleic acids Fats: Saturated fats: from animals Unsaturated fats: from plants Cholesterol Synthesized by liver: 70 mg per day Eat about 225 mg per day Normally level in blood is constant If eat less, liver makes more If eat more, liver makes less Cholesterol carried in blood by proteins called lipoproteins Low density lipoprotein (LDL) High density lipoprotein (HDL) LDL: transports cholesterol from liver to body tissues HDL: transports cholesterol to liver for removal from blood H.Triglycerides = fat 1 gram triglyceride = 2x more energy than 1 gram of carbohydrate One-half of energy comes from triglycerides Stored in fat cells Moderate aerobic exercise results in more demand for energy Comes from triglycerides I.Small intestine: absorption of nutrients takes place Villi: structures that increase surface are to facilitate absorption: Carbohydrates: glucose, monosaccharides Proteins: amino acids Water Minerals Blood flows from small intestine to hepatic portal vein to liver -Excess glucose taken up before blood is returned to circulation.
(lubrication Swallowed food; called; bolus D.Stomach) (Carbohydrates Fats Proteins Nucleic acids Fats: Saturated fats: from animals Unsaturated fats: from plants Cholesterol Synthesized by liver; Eat; about 225 mg per day) (structures; increase; surface) (Esophagus Stomach Small; intestine; Large intestine) (acids Water Minerals Blood; flows; from small intestine to hepatic portal vein to liver -Excess glucose) (triglycerides; Stored; L:in fat cells) (Carbohydrates Fats Proteins Nucleic; acids; Fats) (proteins; called; lipoproteins Low density lipoprotein) (20 feet long Digestion; completed; L:here) (Normally level in blood; is; constant) (2x; Comes; from triglycerides I.Small intestine) (blood; is returned; to circulation) (lubrication; Swallowed; food called bolus D.Stomach: expandable sac Stores and mixes Chemical digestion Movement of food to small intestine E.Chemical digestion Hydrochloric acid Enzymes Chyme)
lubrication Swallowed food Carbohydrates Fats Proteins Nucleic acids Fats: Saturated fats: from animals Unsaturated fats: from plants Cholesterol Synthesized by liver structures Esophagus Stomach Small acids Water Minerals Blood triglycerides Carbohydrates Fats Proteins Nucleic proteins 20 feet long Digestion Normally level in blood 2x blood lubrication
called Eat increase intestine flows Stored acids called completed is Comes is returned Swallowed
bolus D.Stomach
about 225 mg per day
surface
Large intestine
from small intestine to hepatic portal vein to liver -Excess glucose
L:in fat cells
Fats
lipoproteins Low density lipoprotein
L:here
constant
from triglycerides I.Small intestine
to circulation
food called bolus D.Stomach: expandable sac Stores and mixes Chemical digestion Movement of food to small intestine E.Chemical digestion Hydrochloric acid Enzymes Chyme