Chapter 15

The villi in the wall of the small intestine function to a. increase the surface area for absorption. b. help mix the food with digestive enzymes. c. secrete bile d. secrete digestive enzymes.

Why is it possible to swallow while standing on one's hands? a. Valves in the digestive system keep food from moving backward. b. Peristalsis pushes food along the digestive tract in the right direction. c. Bacteria clog the digestive tube and prevent food from moving in the wrong direction. d. A wave of muscle contraction called emulsification prevents food from moving backward.

What is the most important function of the stomach? a. absorption of nutrients b. chemical digestion c. mucus secretion d. storage of food

You go out with your friends to celebrate your birthday and share a sausage pizza. Where does the digestion of the oil begin? a. in the mouth b. in the esophagus c. in the stomach d. in the small intestine

You are a pediatrician. A woman brings in her 1-year-old son, who has severe diarrhea. You would be most immediately concerned about the child's loss of ________ due to the diarrhea. a. water b. fiber c. fat d. protein

What is the longest part of the gastrointestinal tract? a. esophagus b. stomach c. small intestine d. large intestine

Eating which of the following is most helpful in lowering your blood level of LDL cholesterol? a. fiber b. protein c. saturated fats d. carbohydrates

After a meal of greasy fries, which of the following digestive secretions would you expect to be most active? a. salivary amylase b. bile and lipase c. pepsin d. HCl

Which of the following is not a function of saliva? a. begins the chemical breakdown of starches b. helps clean the mouth c. contains fluoride to harden the tooth enamel d. moistens food and helps stick it together to make it easier to swallow

Which of the following statements about vegetarian diets is incorrect? a. A vegetarian diet is likely to contain fewer calories than is a diet that contains meat. b. A vegetarian diet is likely to be lower in saturated fats than is a diet that contains meat. c. Vegetarians must consume milk products for a source of complete proteins. d. A vegetarian diet is likely to be high in complex carbohydrates.

To reduce the amount of fat in your diet, it would be best to reduce your consumption of a. baked potatoes. b. hamburgers. c. spaghetti. d. bread.

________ is a liquid mixture of food and gastric juices found in the stomach.

Saliva contains an enzyme that begins the chemical digestion of _________