Question

The involuntary action in the body are controlled by
A) Spinal Cord
B) Cerebellum
C) Medulla in Forebrain
D) Medulla in hindbrain

Answer 1

Hint: Involuntary action refers to the series of muscle movements which do not require any assistance of the thinking ability.

Complete Answer:
Involuntary actions in short –
Involuntary actions occur without the organism being in its conscious state.

- Option a: Spinal cord is in control of motor, sensory and autonomic functions. But it does not control the involuntary movements, therefore, this is the incorrect option.
- Option b: Cerebellum coordinates voluntary movements and not involuntary movements, therefore, this is the incorrect option.
- Option c: Medulla is not present in the forebrain, so this option is incorrect.
- Option d: It is the medulla region of the human body which exerts its control over the consciousness and arousal; whereas, its three vital reflex centres are responsible for controlling the diameter of the blood vessels, the heartbeats, and the rate of breathing. Therefore, this is the correct option.

Involuntary actions are under the voluntary control of the medulla oblongata which is generally referred to as the midbrain. The involuntary movements are characterised by relatively slower speed. The best example of this movement is the beating movement of the human heart.

Thus, the correct option is d) Medulla in hindbrain.

Note: If you get confused about medulla in hindbrain and medulla in forebrain, then try to remember the structure of forebrain. Once you have done that, you will realise, the forebrain does not contain medulla, and thus medulla is present in hindbrain.