Digestion Flashcards
Longitudinal muscles are:
Down the length of the gut
Peristalsis:
Involves longitudinal and circular muscles
Circular muscles are:
Running in circles around the gut
Job of longitudinal and circular muscles:
Squeeze the food along - called peristalsis
What do waves of circular muscle contractions do:
Push the food along the gut
What do waves of longitudinal muscle contractions do:
Run slightly ahead to help keep the food in a ball
What does bile do:
Neutralises the stomach acid and emulsifiers fats
Where is bile produced:
In the liver and stored in the gall bladder before it’s released into the small intestine
What does hydrochloric acid in the stomach do:
Makes the pH too acidic for enzymes in the small intestine to work properly.
Bile - alkali or acid?
Bile is alkaline - it neutralises the acid and makes conditions alkaline
Enzymes in the small intestine work better in these alkaline conditions
What does bile do to fat:
Bile emulsifies fat - it breaks down the fat into tiny droplets
This gives a much bigger surface area of fat for the enzyme lipase to work on - which makes its digestion faster
Villi:
Provides a really big surface area
Where is villi found:
The small intestine
Villi makes absorbing digested food into the bloodstream really efficient:
Big surface area so that digested food is absorbed much more quickly into the blood
Single layer of surface cells so that digested food diffuses quickly over a short distance
Good blood supply via a capillary network to assist quick absorption of digested food
