Now if the spinal cord is also destroyed, there is no response when the irritation of the skin is repeated. The animal remains perfectly quiet, because the destruction of the cord has interrupted the reflex action pathway. This shows that some part of the central nervous system is necessary to reflex action.
Review description of the spinal nerves, page 295.
Where a deep-seated cause for worry exists, there may be occasion for grave concern. Many people have become insane through continued worry about some one thing. In cases of this kind the sufferer needs the aid of sympathetic friends, and sometimes of the physician, in getting the mind away from the exciting cause. A change of scene, a visit, or some new employment is frequently recommended, where the actual cause for the worry cannot be removed.
Any part of the body which is overworked or which works at a disadvantage tends to disturb, more or less, the entire nervous system and to produce nervousness. Especially is this true of such delicate and highly sensitive structures as the eyes. If the eyes do not focus properly or if the muscles that move the eyeballs are out of their natural adjustment, extra work is thrown upon these delicate parts. One of the first and sometimes the only indication of eye strain is that of some disturbance of the nervous system. For this reason it is important to carefully test the eyes in determining the cause of nervousness (page 385).
One form of neck exercise recommended for this purpose is easily taken on retiring at night. Lying flat on the back, without a pillow, lift the head slowly from the bed and let it as slowly settle back to the level of the body. Repeat several times, lying on the back, and then again on the face and again on each side. Practice these exercises every night during an interval of a month or until relief is secured.
Insurance statistics show that habitual moderate drinkers do not live so long as abstainers.
Organs very frequently affected by tobacco are the heart and the eyes. It induces, as already stated (page 56), a dangerous nervous derangement called "tobacco heart," and it causes a serious disorder of the retina (retinitis) which leads in some instances to loss of vision. Tobacco smoke also acts as an irritant to the delicate lining of the eyes, especially when the tobacco is smoked indoors.
Of 4117 boys in the Illinois State Reformatory, 4000 used tobacco, and over 3000 were cigarette smokers. Dr. Hutchison, of the Kansas State Reformatory, says: "Using cigarettes is the cause of the downfall of more of the inmates of this institution than all other vicious habits combined."
The term "mind" is used in this and preceding chapters in its popular, not technical, sense.
The problem of social adjustment is but a phase of the general problem of establishing proper relations between the body and its surroundings.