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Article: Pain
- Article from:
- Biology
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CopyrightCOPYRIGHT 2002 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Pain
Pain is experienced by humans and animals in response to excessive pressure, heat, or chemicals. Although humans often view pain as undesirable, pain helps protect them from injury by alerting them to its presence. The need for pain is revealed by diseases in which pain is absent or suppressed, as in leprosy. People with such disorders, unaware of injuries or infections, often die prematurely or require limb amputations because unfelt injuries may be neglected until they lead to massive infection and tissue death.
Although skin and other tissues contain cells that are activated by heat and pressure, pain arises from specialized cells that only respond to excessive stimuli that have ...