Q. Consider the following:
  1. Reflex action
  2. Voluntary action
  3. Involuntary action
Which of the above are the responses by the nervous system?

Answer: All of the above
Notes: The responses of the nervous system can be classified as reflex action, voluntary action or involuntary action.
  1. Reflex action is an involuntary and nearly instantaneous movement in response to a stimulus. A reflex is made possible by neural path ways called reflex arcs which can act on an impulse before that impulse reaches the brain.
  2. Voluntary action is an action that is thought of and consciously performed by the person. He has full control over it. It involves the complete motor path way from the cerebral cortex to the last muscle bundle which has to contract.
  3. Involuntary action is one which occurs without the conscious choice of an organism. If it occurs specifically in response to a stimulus, it is known as reflex.