Question

State two differences between the act of chewing food and salivation on sight of food.

Hint:

Voluntary actions (chewing) are conscious and controlled by the brain. Involuntary reflex actions (salivation on sight) are automatic and controlled by the autonomic nervous system.

Answer 1

Two Differences Between Chewing of Food and Salivation on Sight of Food:

Chewing of food and salivation on sight of food are both related to digestion, but they differ in their nature and mechanism. One is a voluntary physical action, while the other is an involuntary reflex action.

1. Nature of Action:

Chewing of Food:
Chewing (mastication) is a voluntary action. It is performed consciously with the help of teeth and jaw muscles to break down food into smaller pieces.

Salivation on Sight of Food:
Salivation on seeing or smelling food is an involuntary reflex action. It occurs automatically without conscious control and is controlled by the nervous system.

2. Type of Process:

Chewing of Food:
It is a mechanical process of digestion. It physically breaks down food into smaller particles, increasing the surface area for enzyme action.

Salivation on Sight of Food:
It is a physiological (chemical preparation) process. Saliva is secreted by salivary glands and contains the enzyme amylase, which begins the digestion of starch.

Conclusion:
Chewing is a voluntary mechanical process that physically breaks down food, whereas salivation on sight of food is an involuntary reflex action that prepares the digestive system for chemical digestion.