THE DIGESTIVE SYSTEM:(MOUTH AND OESOPHAGUS) Flashcards
How is food digested in the mouth?Give one way.
Mechanical digestion, where the teeth chew the food=breaking it down into smaller pieces
to increase the SA:V(ratio)
=So enzymes can digest the food quicker
What enzymes are released in the mouth?How?
The salivary glands secrete amylase
What is amylase?
An example of a carbohydrase(coverts carbs into simple sugars)
What does the amylase do in the mouth?
The amylase enzymes made in the saliva breaks down starch into maltose
Describe another process that happens in the mouth
The food is shaped into a bolus (ball) by the TOUNGE and lubricated in the saliva=to be swallowed easier
What is the oesophagus?
A tube which connects the mouth and the stomach, where the bolus goes after being swallowed
What happens in the oesophagus
peristalsis pushes the swallowed bolus ball down
What is responsible for moving food along the gut?
Muscles
What is the circular muscle layer?
Fibres running in rings AROUND the gut
What is the longitudinal muscle layer?
Fibres running down the length of the gut
What do both the circular and longitudinal muscle layer do?
together they act to push the food along
Describe the process of peristalsis
When the circular muscles contract,
and the longitudinal muscles relax= the gut is made narrower
And when the opposite happens…
The longitudinal muscles contract
and the circular muscles relax= the gut becomes wider
These wave like contractions pass along the gut pushing the food along
Briefly summarise the process of peristalsis in the oesophagus
The muscles contracting and relaxing produce wave-like contractions.
Producing a ‘squeezing action’ that pushes the bolus through the gut.
