amblyaphia


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touch

 [tuch]
1. palpation with the finger.
2. in the nursing interventions classification, a nursing intervention defined as providing comfort and communication through purposeful tactile contact.
3. the sense by which contact of an object with the skin is recognized. Touch is actually not a single sense, but several. There are separate nerves in the skin to register heat, cold, pressure, pain, light touch, and coarse touch. These thousands of nerves are distributed unevenly over the body, so that some areas are more responsive to cold, others to pain, and others to heat or pressure. Each of these types of nerves has a different structure at the receiving end. A nerve for light touch has an elongated bulb-shaped end; one responsive to cold ends in a squat bulb; one that registers warmth ends with what look like twisted threads; and a nerve for deep pressure has an egg-shaped end. Pain receptors have no protective sheath.



If the sensory nerves were evenly distributed over the whole body, each square inch (6.5 square cm) of skin would have about 50 heat receptors, 8 for cold, 100 for touch, and 800 for pain. The sensitivity of a given spot depends in part on how thickly receptors of any one kind are clustered in that spot, and localization of a particular sensation depends on the concentration of the necessary nerve endings in the area. Light touch, pressure, and pain are sensations that can be localized quite accurately, but sensations of cold and heat are more diffuse.

The thickness of the skin in a given area and its supply of hairs also contribute to its touch sensitivity. A touch as light as one fifteen-thousandth of an ounce on the thin skin of the forehead can be felt, whereas a touch must be two and a half times as heavy to be felt on a fingertip. Hairs grow almost everywhere on the skin except the palms of the hands and the soles of the feet. They grow at a slant, and touch spots cluster in the skin near each of them. Even a light touch on the tip of a hair bends it back, and like a tiny lever it communicates the touch to the nerve endings.
therapeutic touch in the nursing interventions classification, a nursing intervention defined as attuning to the universal healing field, seeking to act as an instrument for healing influence, and using the natural sensitivity of the hands to gently focus and direct the intervention process.

am·bly·a·phia

(am'blē-ā'fē-ă)
Diminution in tactile sensibility.
[ambly- + G. haphē, touch]