What is reflex action? Explain with the help of examples.
Answer:
A reflex action is defined as a spontaneous, automatic and mechanical response to a stimuli without the will of an individual. In such actions there is no involvement of the brain. All reflex actions are conveyed through the spinal cord by a path called reflex arc.
The reflex action travels in the following sequence:
The reflex arc constitutes the following components:
- A receptor to perceive the stimulus.
- A sensory or afferent nerve which carries the message from the receptor to the spinal cord.
- The neurons of spinal cord transmit the impulse from afferent neurons to efferent neurons.
- The motor or efferent nerve carries messages from spinal cord to the muscles (effectors) that show the response.
Some examples of reflex actions are:
- Blinking of eyes when a foreign particle gets in them.
- Sneezing if an unwanted particle enters the nose.
- Watering of mouth at the sight or smell of good food.
- Withdrawal of foot while walking if a nail comes in the way and pricks the foot.
- Immediate withdrawal of hand of a person if some hot thing touches it.