Food is moved through the digestive system by a process called peristalsis.
Two sets of muscles in the gut wall are involved:
- longitudinal muscles (which reduce the length of the gut when they contract)
- circular muscles (which reduce the diameter of the gut when they contract)
The muscles work together to produce wave-like contractions.
These have a ‘squeezing action’ that pushes the bolus through the gut. 
You may be interested in
© 2017 MyExpedio.com