(2) Test for touch. Touch the skin with a cotton ball using light strokes. Do
not press down on the skin or touch areas of the skin that have hair. Instruct the patient
to point to the area you have touched or tell you when he feels the sensation of being
touched. (Obviously, he will not be watching you touch his skin.)
Figure 2-5. Testing for touch.
f. Reflexes. A reflex may be defined as an immediate and involuntary
response to a stimulus. A reflex is a fast response to a change in the body's internal or
external environment in an attempt to restore homeostasis.
(1) Reflexes and diagnosis. Evaluation of a reflex can aid a doctor in
diagnosing a problem. A reflex which stops functioning or functions abnormally may
indicate that a particular conduction pathway in the body has been damaged. Testing
internal organs for reflex is not practical for diagnosis, but somatic reflexes (reflexes
resulting in the contraction of skeletal muscles) are excellent diagnostic tools.
(2) Superficial reflexes. Stroke the skin with a hard object such as an
applicator stick. What is felt is a superficial reflex.
(3) Muscle reflexes. Muscle reflexes help determine how responsive the
spinal cord is. If many impulses are transmitted from the brain to the spinal cord, the
muscle reflexes become so sensitive that just tapping the tendon of the knee with the tip
of your finger can cause the leg to jump a considerable distance. If, however, the cord
is overwhelmed by other impulses from the brain, it may be impossible to cause the
muscles or tendons to respond.