THE PAIN NERVES.

Franklin Times, Volume 9, Issue 689, 2 December 1921, Page 5

THE PAIN NERVES.

FOUR MILLION OPPORTUNITIES TO SUFFER. PAIN SUSCEPTIBILITY LARGELY LOCAL. There are between two and four «■ million pain (spots on youn body.. The nerves whose receptive en\ds lie in the skin or just beneath, are now classified into three different kinds. One kind convey to the brain sensations of heat or cold, another kind convey sensations of touch and a third "those of pain. The last are by far the most numerous, for of the thermometer nerves there are only something over half a million and of the nerves of touch rather fewer. The /thermometers on our skin (says Everyday Science) end in little bulbs, but the touch and pain nerves have free ends. They are dis/tributed oven the body in microscopic, dots, forming little groups bii-t some areas are more 1 densely spotted, and these spots are more sensitive than the resh. The pain l , spots are particularly numerous in the corner of the eye—the transparent covering over the iris and pupil—bu|t the touch spots are not- unusually thick there. Contrariwise the finger tips are crowded with touch nerves so close together in the case of a per'son who usefc his .finger tips, for delicate work that they. form something like a miniature brain at the ball of each finger,. But the fmgers, though so sensitive to touch and also to heat and cold, are not ceptionally sensitive to pain. Generally speaking, the left side of the body has more pain spots than the rights the left temple, for instance is more sensitive tq pain (than the right. It is a common experience for a man who has had a leg Amputated to feel pain in the lost limb. This -is called' a “propagated” pain, and is explained' by the faqft that it originates in the trunk of the nerve, but is felt, in the nerve ends. The thermometer nerves are much mb re sensitive to sudden changes of temperature than to gradual change; on the other hand a sudden blow or wound tends to deaden the pain nerves A rifle bullet wound seldom causes pain /Until some time afterwards, if at all; but. if the bullet were forced slowly through the skin and flesh the nerves would resent it strongly- Take an area on the inside of yoUi! iorearm, and mark out a two-inch square with pencil. Then if you probe with ths bltunt end. of & needle you will find some Spots responsive and some quite unresponsive. And others will respond only to heat, and some only to cold.