Peristalsis. Peristalsis includes longitudinal and circular muscles.
All the way through the digestive system there is muscular tissue... there is longitudinal muscles running down the length of the gut and circular muscles running in circles around the gut.
These muscles need to get the food along and through your digestive system they do this by peristalsis. Peristalsis is the squeezing of muscles.
The waves of circular muscle contractions push the food along the gut whereas the longintudinal muscle contractions are slightly ahead to help keep the food in a ball.
Bile. Bile emulsifies fats and …