9781422274293

Pain can be short-term or long-term, it can stay in one place, or it can spread around the body.” How Pain Works The body uses pain to communicate to the brain that something is wrong. For example, consider what happens when a person inadvertently puts her hand on a hot stove burner. The heat immediately begins to damage skin tissue. This activates microscopic pain receptors in the skin, which are located at one end of a nerve cell. The activated receptors send a pain message that says “something is wrong” to the other end of the nerve cell, which is connected to the body’s central nervous system in the spinal cord. After the pain message, which is in the form of an electrical signal, reaches the spinal cord, the message continues to move toward the brain. The pain message signal is transmitted by means of special chemicals, called neurotransmitters, which are released by the nerve cells. These help the message to cross over the gaps (synapses) between nerve cells. The transmission of pain signals happens very quickly, but the body reacts to pain even before the brain recognizes what is happening. When pain receptors are activated, the central nervous system instantly generates a reflex response. For the person who accidentally touched the hot stove, the reflex response would be for her armmuscles to contract, jerking her hand away from the source of the tissue damage. This happens involuntarily, before the brain has even received and processed the pain message. Once the pain message reaches the brain, it goes to an area called the thalamus. This part of the brain sorts through all different types of signals, and sends them to an area of

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What Is Pain?