23. Digestive System

Which of the following is not one of the six basic processes carried out by the digestive system?

a. Propulsion

b. Gas exchange

c. Secretion

d. Absorption

Match the following digestive enzymes with the digestive reaction they catalyze.     

____Salivary amylase     

____Sucrase    

____Trypsin     

____Pancreatic lipase     

____Pancreatic amylase     

____Pepsin

a. Breaks down sucrose into glucose and fructose in small intestine

b. Digests lipids in small intestine

c. Breaks down proteins into polypeptides in stomach

d. Breaks down polysaccharides into oligosaccharides in small intestine

e. Assists in protein digestion in small intestine and activates other protein-digesting enzymes

f. Breaks down polysaccharides into oligosaccharides in the mouth

Which of the following statements about absorption in the small and large intestines is false?

a. Absorption of water occurs by secondary active transport.

b. Absorption of sodium ions creates an electrical gradient that drives absorption of chloride and bicarbonate anions.

c. Fat-soluble vitamins are absorbed with other lipids.

d. Vitamin B12 requires intrinsic factor to be absorbed in the small intestine.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Motility of the alimentary canal is regulated by the enteric nervous system, the parasympathetic nervous system, and hormones.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. Control of gastric emptying into the duodenum is important to allow the chyme to be neutralized and diluted by pancreatic secretions.

Your friend insists that absorption is the most important process carried out by the digestive system. What do you think of this claim? How would you respond?