- food in mouth stimulates salivary glands to secrete saliva
- saliva is mixed with food to soften it
- Saliva → contains an enzyme called salivary amylase → which digests/breaks down starch into maltose.
- optimum pH for salivary amylase → pH 7 → enzyme is most active. refer to (Enzymes)
- chewing breaks up food into smaller pieces. increases SA to V ratio of food pieces to enzyme action.
- Tongue - rolls food into small, slippery round masses called boli (bolus)
- Boli - swallowed and passed down into the oesophagus via the pharynx
- peristalsis in the walls of the oesophagus pushes each bolus of food down into the stomach