Page 129 - Primary Five Science

Mouth or Oral Cavity

Teeth

Breaks down food mechanically or physical-

ly by chewing. It’s important to chew food

properly so that it will be digested easily

and without damaging the alimentary canal

lining.

Salivary glands

Are accessory organs located under the tongue.

They are stimulated by presence of food to se-

crete saliva into the mouth. Saliva can also be stimulated by

sight or smell of food.

Saliva

 Lubricates and softens the food for easier swallowing.

 Saliva also contains an enzyme ptyalin or salivary amylase

which chemically breaks down cooked starch or carbohy-

drates to maltose.

 Saliva also cools and lubricates the food so that it moves eas-

ily to the stomach.

Tongue

 Tastes food,

 Rolls and mixes food into a bolus

 Pushes food to the gullet

Epiglottis

Closes and covers the trachea during swallowing