If you touch a hot pot in the kitchen, you quickly jerk your hand away. You do not think about pulling your hand away you act automatically. This automatic action is called a reflex action. In a reflex action, the nerve impulse takes a special pathway, called a reflex arc. In the case of your touching the hot pot, the impulse moved from the skin where it came in contact with the pot along a sensory nerve to your spinal cord. Here the impulse set off another impulse in a motor nerve running from your spinal cord to your arm muscles.
The muscles contracted and pulled your hand away from the pot about one-tenth of a second. At the same time the original sensory impulse traveled to your brain, where you felt it as pain.
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