Question

practice 11
what causes peristalsis?
the absorption of nutrients in the small intestine
the function of the salivary glands in the mouth
the release of digestive enzymes from the pancreas
the contraction and relaxation of the muscles in the walls of the digestive tract
the production of bile in the liver

Explanation:

Peristalsis is the wave - like movement that propels food through the digestive tract. It is caused by the coordinated contraction and relaxation of the smooth muscles in the walls of the digestive tract.

• The absorption of nutrients in the small intestine is a function related to digestion but not the cause of peristalsis.
• The function of salivary glands in the mouth is related to initial digestion (moistening food, starting starch digestion) but not peristalsis.
• The release of digestive enzymes from the pancreas is for chemical digestion, not peristalsis.
• The production of bile in the liver is for fat emulsification, not peristalsis.

Answer:

The contraction and relaxation of the muscles in the walls of the digestive tract.