Science: Process of Digestion

Mouth
Food starts its long journey at the mouth. The mouth is the first part of the digestive system. The food is broken up with the help from saliva. Saliva contains an enzyme that breaks up the starch from food into smaller molecules. An adult produces about a litre of saliva each day.
Oesophagus
The oesophagus is the organ where bits of food swallowed are pushed down. It connects the throat above with the stomach below. At the intersection of the oesophagus and stomach, there is a ring-like controlling device that closes the passage between the two organs. …