Answer the following question: Answer the following question given this paragraph: Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure below shows how peristalsis works. Q: What do the muscles of the gastrointestinal tract do? Choices: - break down food - secrete stomach acid - stop digestion - keep food moving A:
Answer:
keep food moving