A wave that pushes
Peristalsis moves food along the gut.
A long tube
Food that you swallow travels along a long tube inside the body.
What do you think pushes the food along the tube?
What this lesson covers
The idea
Muscles in the lining of the alimentary canal contract rhythmically to push food forward in a regulated manner; these peristaltic movements occur all along the gut.
A long tube
Food that you swallow travels along a long tube inside the body.
What do you think pushes the food along the tube?
- Muscles in its lining
- Only the weight of the food
- The air we breathe
Squeeze and push
Press Next step to watch the squeeze move along.
Rhythmic muscles
The food has to be moved along in a regulated manner so that each part of the canal can process it properly. The muscles in the lining of the canal contract rhythmically to push the food forward. These movements are called peristaltic movements, and they occur all along the gut.
Muscles in the lining of the alimentary canal contract rhythmically to push food forward in a regulated manner; these peristaltic movements occur all along the gut.
Notes
Muscles in the lining of the canal contract rhythmically to push food forward in a regulated manner: peristaltic movements, all along the gut.
Check yourself
What pushes food forward along the alimentary canal?
Why must food be moved along in a regulated manner?
Where do peristaltic movements occur?
The rhythmic squeezing of the canal that pushes food forward is called ...
- Saliva. Saliva wets the food so that its passage is smooth; the muscles in the lining of the canal push it forward.
- Hydrochloric acid. Hydrochloric acid in the stomach makes the medium acidic for pepsin; it does not push food along.
- Muscles in the lining that contract rhythmically — correct. Yes!
- So that it can be processed properly in each part — correct. Yes!
- So that it stays in the mouth. The food is meant to pass through the whole tube, with each part processing it in turn.
- So that the teeth can crush it. Teeth crush the food in the mouth; peristaltic movements push it forward along the canal.
- Only in the mouth. In the mouth, teeth crush the food and the tongue mixes it. Peristaltic movements occur all along the gut.
- All along the gut — correct. Yes!
- Only in the stomach. The book says peristaltic movements occur all along the gut, not in the stomach alone.
- emulsification. Emulsification is the breaking of fat globules into smaller ones by bile salts.
- diffusion. Diffusion is the spreading of substances, for example into the cytoplasm of Amoeba; it is not a squeezing of muscles.
- peristalsis — correct. Yes!