Word: paines
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Dates: during 1980-1989
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...debated among the ancient Greeks, until philosophers like Democritus and Plato concluded correctly that the pain-perception center is the brain. Greek scientists found support for this theory by discovering that the brain is connected to a network of two types of nerve fibers, one set controlling motion, the other, sensation. This knowledge was lost in the Middle Ages, and superstition again took hold. Only when taboos against dissection were lifted during the Renaissance did thinkers like Leonardo da Vinci once again understand pain in terms of the nervous system...
Most refinements of this understanding have come about in the past 20 years. Today scientists have a fair idea of what happens physiologically when, for example, the big toe collides with a large, solid object. Not surprisingly, the pain message originates at the point of contact (see diagram). It begins with the release of a number of potent chemicals that are normally stored in or near nerve endings for use on just such clumsy occasions. Among these chemicals are the mysterious substance P (for pain), prostaglandins and bradykinin, probably the most painful substance known to man-just a tiny amount...
...pain signal from the stubbing of the toe travels as an electrochemical impulse along the length of the nerve to the dorsal horn of the spinal cord, a region that runs the length of the spine and receives signals from all over the body. In a tall person, the distance from toe to dorsal horn may be more than one meter, and it can take about two seconds for the message to arrive. From there, it is relayed in a bewildering flurry of chemical messages to the brain, first to the thalamus, where sensations like heat, cold, pain and touch...
...electrode into the consciousness." In any case, it is the cortex that coordinates such highly sophisticated responses to pain as screaming "Ouch!" and rubbing the sore...
...seems, has its purpose, and one can get considerable relief by massaging or patting a sore area, just as one can relieve itching by scratching or slapping. In 1965 two researchers, Patrick Wall and Ronald Melzack, devised a brilliant theory to explain this effect: the gate-control theory of pain. According to them, only a limited amount...