| A | B |
|---|
| proteins, carbohydrates, fats, vitamins, minerals, water | six groups of nutrients |
| digestion | process of breaking down food into simpler substances |
| saliva | released by the salivary glands |
| ptyalin | breaks down starches into simple sugars |
| chemical digestion | breaking down of food into simple substances by the action of enzymes |
| mechanical digestion | occurs when food is broken down by chewing and by the churning movements of the digestive tract |
| esophagus | food enters this tube after leaving the mouth |
| peristalsis | pushes food downward into the stomach |
| stomach | releases gastric juice, which contains hydrochloric acid, mucus, and pepsin |
| pepsin | an enzyme that breaks down proteins into amino acids |
| small intestine | where the majority of digestion takes place |
| bile | produced in the liver, stored in the gall bladder, and aids in digestion in the small intestine |
| liver | the heaviest organ in the digestive system |
| pancreatic juice | travels to the small intestine and digests proteins, starches, and fats |
| villi | fingerlike structures that line the small intestine and aid in absorption of nutrients |
| large intestine | absorbs most of the water from the undigested food |
| rectum | stores undigested food substances |
| anus | opening through which wastes leave the body |
| exercise | helps to strengthen the heart, develop better posture, firm up muscles, build a stronger body, and increase endurance |
