Question

Nervous actions are of three types.   

1. Reflex action 

2. Involuntary action. 

3. Voluntary action.

 

 

Answer 1

Concept:. 

Reflex action:

Reflex action or reflex is an involuntary action in response to a stimulus. This is a spontaneous action without thinking. For example, we adjust our eyes when exposed to bright light. The peripheral nervous system (PNS) is a system of nerves which connect the central nervous system (CNS) (includes the brain and spinal cord) with other parts of the body.  Reflex action is the result of the coordination of the spinal cord and peripheral nervous system. This action does not involve the brain. The pathway in which impulses travel during the reflex action is called a reflex arc.

 Voluntary action:

When an action is produced with the involvement of thoughts, they are called voluntary action. It involves actions like walking, eating, jumping and running. These actions are produced consciously. Both spinal cord and brain are involved and these coordinate with PNS to generate necessary movements.

Involuntary action:

Actions which take place without consciousness or willingness of an individual are called the involuntary action. Digestion, heart beating, sneezing, etc are few examples of involuntary actions.

Both involuntary and voluntary actions are controlled by the same parts of the brain. Hindbrain and midbrain control involuntary actions like salivation, vomiting, etc. All the body’s voluntary actions are controlled by the motor cortex in the frontal lobe of the cerebrum.

Reflex action or reflex is an involuntary action in response to a stimulus. This is a spontaneous action without thinking. 

When an action is produced with the involvement of thoughts, they are called voluntary action.