Peristalsis

Question 1

Peristalsis

Answer 1

Two layers of smooth muscles causes rhythmic, wave-like contractions of the walls of the guts
- Help to move food along the gut
(Wave of muscle contractions passes along the canal pushing food in front of it)

Question 2

Antagonistic muscle action

Answer 2

The two sets of muscle work in such a way that when one contracts, the other relaxes

• When the circular muscle contracts, the longitudinal muscle relaxes. The gut constricts (Lumen becomes smaller and becomes narrower but longer) , thus the food is squeezed and pushed forward.
• When the longitudinal muscle contracts, the circular muscle relaxes. The gut dilates (Lumen becomes bigger and becomes wider but shorter), thus the hollow lumen of the gut is widened for food to enter