Mouth and Oesophagus Flashcards
what is the first structure in the alimentary canal?
the mouth
where does ingestion take place?
the mouth
what does digestion take place?
the mouth
what are the two types of digestion?
mechanical and chemical
mechanical digestion definition?
food is broken up into smaller pieces in the mouth by chewing
- this increases the surface area for enzymes and also prevents discomfort when swallowing
chemical digestion?
saliva is released into the mouth by the salivary glands, it makes the food easier to swallow, and also contains the enzyme amylase, amylase breaks down the starch to maltose
enzyme amylase when reacted with starch?
starch —–amylase—–> maltose
what pH does amylase work best at?
neutral
what happens when amylase reaches the stomach?
it denatures - the pH is too high
how does swallowing work?
- before swallowing the food is shaped into a ball (a bolus) by the tongue and moved towards the back of the mouth
- there is a flap called the epiglottis which blocks the food from entering the trachea
where does food travel down to get to the stomach?
the oesophagus
how does food get pushed down the oesophagus?
peristalsis - wave like contractions
where else does peristalsis occur?
small and large intestines
what muscles push the food down the oesophagus?
- circular muscles which contract behind the bolus
- longitudinal muscles which make the oesophagus wider
