A Treatise on Anatomy, Physiology, and Hygiene (Revised Edition) by Calvin Cutter (read more books .txt) π
13. One of the most important distinctions between animals and plants, is the different effects of respiration. Animals consume the oxygen of the atmosphere, and give off carbonic acid; while plants take up the carbonic acid, and restore to animals the oxygen, thus affording an admirable example of the principle of compensation in nature.
14. But the decisive distinctions between animals and plants are
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188. How should exercise be taken? What is said respecting irregular exercise? Are the consequences of neglected exercise immediately apparent? What practical observation is given? 189. Should every muscle have its due amount of exercise? Mention some employments that only call into action the muscles of the upper limbs. Those of the lower limbs, those of the trunk and limbs. Mention, in the different pastimes, what muscles are called into action.
190. The proper time for labor or exercise should be observed. This is modified by many circumstances. As a general rule, the morning, when the air is pure and the ground dry, is better than the evening; for then, the powers of the body are greatest. Severe exercise and labor should be avoided immediately before or after eating a full meal, for the energies of the system are then required to perform the digestive function. For similar reasons, it is not an appropriate time for energetic muscular action immediately before or after severe mental toil, as the powers of the system are then concentrated upon the brain.[6]
What kinds of exercise are best? 190. What rule is given respecting the time for exercise? 191. Why do the muscles require sleep? What is the effect of an inversion of the law of rest?
191. The muscles require sleep to restore their expended energies. Among the arrangements of creative wisdom, no one harmonizes with the wants of the system more than the alternation of day and night. The natural inclination of man to sleep, is in the stilly hour of night, when all nature reposes, and to be in action during the light of day. An inversion of this law of rest causes greater exhaustion of the system than 93 the same amount of exertion during daylight. This is illustrated by the wearied and exhausted condition of watchers, night-police, and other individuals who spend a part of the night in some active business of life.
192. The muscles should not be compressed. Compression prevents the blood from passing to the muscles with freedom; consequently, they are not supplied with material to renovate and promote their growth. Again, pressure stimulates the lymphatics to action; and by the increased activity of these vessels the muscles are attenuated. In the case of a man with a fractured limb, the muscles are not only enfeebled by inaction, but diminished in size by compression from the dressing. Limbs enfeebled in this way will not recover their size, tone, and strength, until the bandages are removed, and a proper amount of exercise taken.
193. The pressure of tight dresses, under the name of a βsnug fit,β enfeebles the muscles of the back, and is a common cause of projecting shoulders and curvature of the spinal column. Thus every appendage to the dress of ladies which prevents free motion of the muscles of the chest and spinal column, weakens the muscles thus restrained, and not only prevents the proper expansion of the lungs, but, by weakening the muscles which sustain the spine, induces curvature and disease. Whalebone, wood, steel, and every other unyielding substance, should be banished from the toilet, as enemies of the human race.
194. The mind exerts a great influence upon the tone and contractile energy of the muscular system. A person acting under a healthy mental stimulus will make exertion with less fatigue than he would without this incentive. For this reason, a sportsman will pursue his game miles without fatigue, while 94 his attendant, not having any mental stimulus, will become weary. Again, if the sportsman spends some hours in pursuit of his favorite game without success, a feeling of languor creeps over him; but while he is thus fatigued and dispirited, let him catch a glimpse of the game,βhis wearied feelings are immediately dissipated, and he presses on with renewed energy and recruited strength.
192. Why should not the muscles be compressed? 193. What is the effect of tight clothing upon the muscles? 194. What is said of the influence of the mind upon muscular activity? Give an illustration of mental stimulus coΓΆperating with muscular activity in the case of a sportsman.
195. This principle was well illustrated in the retreat from Russia of the defeated and dispirited French army. When no enemy was near, they had hardly strength sufficient to carry their arms; but no sooner did they hear the report of the Russian guns, than new life seemed to pervade them, and they wielded their weapons powerfully until the foe was repulsed, then there was a relapse to weakness, and prostration followed. It is thus with the invalid when riding for his health;βrelate an anecdote, or excite this mental stimulus by agreeable conversation, and much benefit will accrue from the ride to the debilitated person. So it is in the daily vocations of life; if the mind have some incentive, the tiresomeness of labor will be greatly diminished. Let an air of cheerfulness ever pervade our every employment, and, like music, βit sweetens toil.β
196. Facts illustrative of the inutility of calling the muscles into action, without the coΓΆperation of the mind, are seen in the spiritless aspect of many of our boarding school processions, when a walk is taken merely for exercise, without having in view any attainable object. But present to the mind a botanical or geological excursion, and the saunter will be exchanged for the elastic step, the inanimate appearance for the bright eye and glowing cheek. The difference 95 is, simply, that, in the former case, the muscles are obliged to work without that full nervous impulse so essential to their energetic action; and that, in the latter, the nervous influence is in full and harmonious operation.
195. Give an illustration of mental stimulus coΓΆperating with muscular activity in the case of the dispirited French army in their retreat from Russia. How can a union of mental impulse and muscular action be beneficial to an invalid? Does this same principle apply to those who labor? 196. Give an instance of the different effects produced by the absence and presence of the mental stimulus.
197. It must not, however, be supposed that a walk simply for the sake of exercise can never be beneficial. Every one, unless prevented by disease, should consider it a duty to take exercise every day in the open air; if possible, let it be had in combination with harmonious mental exhilaration; if not, let a walk, in an erect position, be made so brisk as to produce rapid respiration and circulation of the blood, and in a dress that shall not interfere with free motions of the arms and free expansion of the chest.
Observation. The advantages of combining harmonious mental excitement, with muscular activity, is thus given by Dr. Armstrong:β
βIn whateβer you sweat,
Indulge your taste. Some love the manly toils
The tennis some, and some the graceful dance;
Others, more hardy, range the purple heath
Or naked stubble, where, from field to field,
The sounding covies urge their labβring flight,
Eager amid the rising cloud to pour
The gunβs unerring thunder; and there are
Whom still the mead of the green archer charm.
He chooses best whose labor entertains
His vacant fancy most; the toil you hate
Fatigues you soon, and scarce improves your limbs.β
197. May not a walk, simply as an exercise, be beneficial? What is preferred?
198. The erect attitude lessens the exhaustion of the muscles. A person whose position is erect will stand longer, walk further, and perform more labor, than an individual whose position is stooping, but equal in all other respects. The manly port in an erect attitude, depends chiefly upon the action of the muscles of the back; and it follows that the fewer the muscles in a state of tension, the less the draught upon the nervous system, and the less its exhaustion. Another advantage which attends the erect position is, the trunk and head are balanced upon the bones and cartilages of the spinal column. If the body slightly incline forward, the muscles attached to the posterior side of the spine, by a gentle contraction, will bring it to the perpendicular, and even incline it backward. This is immediately removed by a slight contraction of the muscles upon the anterior side of the spinal column.
199. In the erect position, there is a constant slight oscillation of the body backward and forward, like the movement of a pendulum; while, in the stooping posture, the muscles on the posterior side of the spinal column are kept in a state of continued tension and contraction, to prevent the body from falling forward. This enfeebles the muscles of the back, and exhausts the nervous energy, while the erect position favors their development and power, because there is an alternate contraction and relaxation of the muscles. Again, in the stooping position, the lower limbs are curved at the knee. In 97 this attitude, there is a constant tension of the muscles of the lower extremities, which produces muscular exhaustion.
198. Why will a person who stands erect walk further, and perform more labor, than if he assumed the stooping posture? 199. Why are the muscles of the back so soon exhausted in the stooping position?
Fig. 48.
Fig. 49.
Fig. 48. 1, A perpendicular line from the centre of the feet to the upper extremity of the spinal column, where the head rests. 2, 2, 2, The spinal column, with its three natural curves. Here the head and body are balanced upon the spinal column and joints of the lower extremities, so that the muscles are not kept in a state of tension. This erect position of the body and head is always accompanied with straight lower limbs.
Fig. 49. 1, A perpendicular line from the centre of the feet. 2, Represents the unnatural curved spinal column, and its relative position to the perpendicular, 1. The lower limbs are curved at the knee, and the body is stooping forward. While standing in this position, the muscles of the lower limbs and back are in continued tension, which exhausts and weakens them.
What is represented by figs. 48 and 49?
98200. When it is necessary to call into action a part of the muscles of the system in the performance of any duty, as those of the lower limbs in walking, if the muscles of other parts are in a state of inaction, the influence of the nervous system can be determined in an undivided manner upon those parts of the lower limbs in action; hence they will not so soon become wearied or exhausted, as when this influence is divided between a greater number of muscles. In performing any labor, as in speaking, reading, singing, mowing, sewing, &c., there will be less exhaustion, and the effort can be longer maintained in the erect position of the body and head, than in a stooping attitude.
Experiment. Hold in each hand a pail of water or equal weights, in a stooping posture, as long as it can be done without much suffering and injury. Again, when the muscular pain has ceased, hold the same pails of water, for the same length of time, in an erect posture, and note the difference in the fatigue of the muscles.
201. If the stooping posture is acquired in youth, we are quite certain of seeing the deformed shoulders in old age. Hence the importance of duly exercising the muscles of the back, for when they are properly developed, the child can and will stand erect. In this attitude, the shoulders will be thrown back, and the chest will become broad and full.
202. Pupils,
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