Physiology and Hygiene for Secondary Schools

by Francis M. Walters

Physical Exercise properly taken is beneficial to the nervous system through both direct and indirect effects. A large proportion of the nerve cells have for their function the production of motion, and these are called into play only through muscular activity. Then, as already suggested, physical exercise counteracts the unpleasant effects of mental work. Hard study causes an excess of blood to be sent to the brain and a diminished amount[pg 329] to the arms and to the legs. Physical exercise redistributes the blood and equalizes the circulation. Light exercise should, therefore, follow hard study. The student before retiring at night is greatly aided in getting to sleep and is put in a better condition for the next day's work by ten to fifteen minutes of light gymnastics. A daily walk of two or three miles is also an excellent means of counteracting the effects of mental work. The brain worker should, however, avoid violent exercise or the carrying of any kind of exercise to exhaustion.

Sleep, and plenty of it, is one of the first requirements of the nervous system. It is during sleep that the exhausted brain cells are replenished. To shorten the time for sleep is to weaken the brain and to lessen its working force. No one should attempt to get along with less than eight hours of sleep each day and most people require more. Children require more sleep than adults. Those under six years should have from eleven to twelve hours of sleep per day. Children between six and ten years should have at least ten hours.

Insomnia, or sleeplessness, on account of its effects upon the nervous system, is to be regarded as a serious condition, and hygienic means for relieving it should be diligently sought. Having its cause in nervousness, a disturbed circulation of the brain, or some form of nervous exhaustion, it is benefited through relieving these conditions and in the manner already described. Of course the external conditions for aiding sleep should not be overlooked. The bed should be comfortable, and the room should be cool, well ventilated, dark, and quiet. The inducing of sleep by means of drugs is a dangerous practice and should never be resorted to except under the direction of the physician.

[pg 330]Effects of Heat and Cold.—Heat and cold both have their effects upon the nervous system. Heat increases the nervous irritability, while cold acts as a natural sedative to the nerves. A nervous person is made more nervous by an overheated atmosphere, but derives beneficial effects from exposing the body freely to cold air and water. The tonic cold bath (page 273), if taken with the usual precautions, can be used to good advantage in diminishing nervousness. The taking of outdoor exercise in cold weather is, for the same reason, an excellent practice.

Effect of Emotional States.—We have already noted the effect of certain emotional states upon the digestion of the food (page 162). Emotional states are also known to interfere with breathing and with the action of the heart. Such effects are explained through the close relation of the mind to the work of the nervous system in general. While certain emotional states, such as fear, anger, melancholia, and the impulse to worry, interfere seriously with the normal action of the nervous system, others, such as contentment, cheerfulness, and joy, are decidedly beneficial in their effects. How important, then, is the habit of suppressing the states that are harmful and of cultivating those that are beneficial. From a hygienic, as well as social, standpoint a cheerful, happy disposition is worth all the effort necessary for its attainment.

The Nervous Condition of Children should be a matter of deep concern on the part of both parents and teachers. In the home, as well as in the school, the child may be "pushed" until the nervous system receives permanent injury. Exhaustion of nerve cells is produced through too many and too vivid impressions being made upon the immature brain. The child should be protected from[pg 331] undue excitement. He should have the benefit of outdoor exercise and should be early inured to cold. He should be shielded from the poisoning effects of tea, coffee, tobacco, alcohol, and other drugs. He should have impressed upon him the habit of self-control. He should not be indulged in foolish caprices or whims, but should be taught to be content with plain, wholesome food and with the simple forms of enjoyment.

Influences at School.—School life is necessarily a great strain upon the child. Night study added to the work of the day makes a heavy burden for elementary pupils to bear. Though the legal school age is usually fixed at six years, delicate children should be kept out of school until they are seven or eight years old, provided they have good homes. In addition to the excitation incident to studying and reciting lessons, conditions frequently arise both in the schoolroom and upon the playground that create a feeling of fear or dread in the minds of children. Quarrels and feuds among the children and the bullying of big boys on the playground may work untold harm. All conditions tending to develop fear, uneasiness, or undue excitement on the part of children should receive the attention of those in authority.

Excessive Reading is a frequent cause of injury to the nervous systems of children. This has a bad effect, both on account of too many impressions being made upon the mind and also on account of the strain to the eyes. Then if the reading consists mostly of light fiction, the mind is directed away from the really important things of life. The reading of children should be thoughtfully controlled, both as to quality and quantity. Exciting stories should, as a rule, be excluded, but a taste for biography, historical and scientific writings, and for the great works[pg 332] of literature should be cultivated. Simple fairy tales which have a recognized value in developing the imagination of the child need not be omitted, but it is of vital importance that the "story-reading habit" be not formed.

Effects of Drugs.—Because of its delicacy of structure a number of chemical compounds, or drugs, are able to produce injurious effects upon the nervous system. Some of these are violent poisons, while others, in small quantities, are mild in their action. Certain drugs, in addition to their immediate effects, bring about changes in the nervous system which cause an unnatural appetite, or craving, that leads to their continued use. This is the case with alcohol, the intoxicating substance in the usual saloon drinks, and with nicotine, the stimulating drug in tobacco. The same is also true of morphine, chloral, and several other drugs used as medicines. The danger of becoming a slave to some useless and pernicious habit should dissuade one from the use of drugs except in cases of positive emergency.

Alcohol and the Nervous System.—Alcohol, as already shown, injures practically all portions of the body; but it has its worst effects upon the nervous system. Through its action on this system, it interferes with the circulation of the blood, produces a condition of "temporary insanity" called intoxication, weakens the will, and eventually dethrones the reason. Worst of all, it produces a condition of "chronic poisoning" which manifests itself in an unnatural craving, and this causes it to be used by the victim even when he knows he is "drinking to his own destruction." Though its use in small quantities does not, as a rule, produce such marked effects upon the nervous system, it develops the "craving," and this is apt in time to lead to its use in larger quantities. But even if this does not occur, the practice is objectionable for its unhygienic effects[pg 333] in general.[111] Tippling with such mild solutions of alcohol as light wine, beer, and hard cider is, for these reasons, a dangerous pastime.