Page 130 - Primary Five Science

Oesophagus or Gullet

The gullet is a muscular tube that passes food from the mouth

to the stomach. Food is pushed through the gullet into the

stomach by a process called peristalsis.

Stomach

This is a j-shaped bag about 1-1.5 litre

capacity. However, its surface area is in-

creased by presence of circular folds called the

rugae.

 Absorption of some medicines, alcohol and

simple sugars occurs in the stomach.

 The stomach is also where digestion of

proteins starts.

 Peristalsis continues

to churn food into a

thick liquid paste

called chyme.

 The walls of the stomach produce

a juice called gastric juice.

Gastric juice contains;

1. Hydrochloric acid

 Kills germs which come along with the food.

 The acid also activates pepsinogen to pepsin in order to

breakdown proteins.

 The acid provides a PH favourable for stomach enzymes to

work.