Question

Which of the following is not an involuntary action?

• A. Vomiting
• B. Salivation
• C. Heartbeat
• D. Chewing

Answer 1

The correct option is D

Chewing

The correct option is D.

Explanation for correct option:

1. The voluntary and involuntary activities are controlled and monitored by the nervous system.
2. Involuntary activities are those, which are not under one’s control, and which can take place spontaneously.
3. The activities, which are under one’s control and comprise conscious thinking are voluntary actions.
4. Chewing is a voluntary activity not involuntary.
5. It is performed by one’s will and comprises the work of skeletal muscles.
6. The food is chewed voluntarily with the help of teeth and is regulated by the mastication muscles.
7. The voluntary activities are controlled by the cerebrum, that is, the part of the central nervous system.

Explanation for incorrect options:

Option A:

1. The involuntary activities are controlled by the autonomic nervous system, that is, the part of the peripheral nervous system.
2. Vomiting is an involuntary activity, which is not under the control of one’s will.

Option B:

1. Salivation is an involuntary activity, which takes place involuntarily after seeing or smelling the food.

Option C:

1. The heart is formed of a unique involuntary muscle known as cardiac muscle.
2. It keeps beating all the time involuntarily.

Final answer: Chewing is not an involuntary action.