What is a reflex? What are the types of reflexes and how do the reflexes work? Information about reflexes and importance.
Reflexes are protective actions involving the spinal cord and/or the brain. In a reflex action the impulse (message) travels from receptors through a sensory neuron to the spinal cord. The association neuron in the spinal cord sends the impulse (message) directly to a motor neuron carries the impulse to the organ that responds.
When your hand touches a hot stove it is pulled back before you feel the sensation of heat or pain. This removal of your hand is an example of reflex action. Most reflexes protect you from harm. Coughing and sneezing are reflexes that help to remove objects from your throat and air passage.
Suppose your finger is accidentally pricked by a sharp pin
- ı. The receptors in your fınger are suddenly stimulated.
- 2. They send impulses (messages) along sensory neurons to your spinal cord.
- 3. Association neurons in the spinal cord transfer the impulse from sensory neurons to motor neurons.
- 4. The motor neurons send impulses to your arm muscles.
- 5. Your arm muscles contract and pull your hand away from the pin.
By this time messages have reached your brain. Your brain interprets what has happened and pain is felt.
When a doctor is checking a person, he sometimes taps the person’s knee in a certain place and his leg jumps up . The jumping of the leg is another example of a reflex. The leg jumps up in the manner explained above. The doctor taps your knee to check the condition of your nerves and spinal cord. Reflex action shows us how some parts of the body are moved independently of the brain. In this case the spinal cord is the message center.
The reflex takes only a fraction of a second, and this shows how quickly the messages travel through the nervous system. Reflexes help the body to react quickly to changes in the environment.