Autonomic nervous system

“ The pathology of these disorders would be more fully understood were our knowledge of the physiology of the heart's movements more complete. We know that contractions of the heart continue when it is separated from all its nervous connections and after removal from the body, especially in cold-blooded animals. The rhythm, frequency, and force of its normal movements are evidently dependent on influences derived through the sympathetic and pneumogastric nerves. ”

“ The heart, then, during the act of smoking, was doing extra work; in some of the experiments this additional labor amounting to more than 50 per cent.
The effect upon the heart is not caused by direct action upon that organ, but by paralyzing the minute vessels which form the batteries of the nervous system. Thus paralyzed, they can no longer offer effectual resistance, and the heart, freed from their control, increases the rapidity of its strokes, expanding the vessels, with an apparent accession, but real waste of force. ”

“ Through the special senses environmental stimuli reach the brain and cause it to liberate energy, which in turn activates certain other organs and tissues, among which are the adrenals. The increased output of adrenalin activates the brain to still greater activity, as a result of which again the entire sympathetic nervous system is further activated, as is manifested by increased heart action, more rapid respiration, raised blood-pressure, increased output of glycogen, increased power of the muscles to metabolize glucose, etc. ”

“ The movements performed by the respiratory organs for the modification of the currents of air being produced by muscles owing their activity to nerves—motor and sensory—and the vocal organs being, like all parts of the organism, provided with nerves, it becomes evident that a general excitation of the nervous system, or any unusual excitement of the motor-nerves in action, will affect the muscles, cause irritation and create disturbances in inspiration, expiration and speech. ”

“ The stimulus of a fly on the nose would be at once superseded by the crushing of a finger. In quick succession do the various receptors (Sherrington) occupy the final common path, but each stimulus is for the time the sole possessor, hence the nervous system is integrated (connected) to act as a whole. Each individual at every moment of life has a limited amount of dischargeable nervous energy. This energy is at the disposal of any stimulus that obtains possession of the final common path, and results in the performance of an act. ”

“ The sympathetic nervous system is the conveyor of vital force to the organs and cells of the body. Just what this vital force is and where it ultimately comes from, we do not know. It is a manifestation of that which we call God, Nature, Life, the Higher Power or the Divine Within.
Heart action, the circulation of the blood, respiration, digestion, assimilation of food, elimination and all other involuntary activities and functions of the human organism are controlled by means of the sympathetic nervous system. The nature of the controlling force itself is not known to us. ”

“ Animals whose natural defense is in muscular exertion, among which is man, may have their dischargeable nervous energy exhausted by fear alone, or by trauma alone, but most effectively by the combination of both. What is the mechanism of this discharge of energy? It is the adequate stimulation of the nociceptors and the physiologic response for the purpose of self-preservation. According to Sherrington, the nervous system responds in action as a whole and to but one stimulus at a time. ”

“ Even the nervous system suffers from improper breathing, inasmuch as the brain, the spinal cord, the nerve centers, and the nerves themselves, when improperly nourished by means of the blood, become poor and inefficient instruments for generating, storing and transmitting the nerve currents. And improperly nourished they will become if sufficient oxygen is not absorbed through the lungs. ”

“ In sleep, the cerebro-spinal system sleeps; the organic system retains its activity. Thus in sleep the voluntary muscles and parts fail to receive their nervous stimulation; but the involuntary receive theirs still, and under it move in steady motion; while the semi-voluntary organs also receive sufficient stimulation to keep them in motion.
Of all the involuntary organs, the heart, which is the citadel of motion, is most protected. To itself belongs a special nervous centre, that which feeds it steadily with stimulus for motion ”

“ The parts of the autonomic system—the cranial, the sympathetic, and the sacral—have a number of peculiarities which are of prime importance in accounting for the bodily manifestations of such affective states.
The Extensive Distribution of Neurones of the “Sympathetic” Division and Their Arrangement for Diffuse Action
The fibres of the sympathetic division differ from those of the other two divisions in being distributed through the body very widely. They go to the eyes, causing dilation of the pupils. They go to the heart and, when stimulated, they cause it to beat rapidly. ”

“ That is to say, of the bodily muscles, the respiratory are more constantly implicated than any others in those various acts which our feelings impel us to; and, hence, when there occurs an undirected discharge of nervous energy into the muscular system, it happens that, if the quantity be considerable, it convulses not only certain of the articulatory and vocal muscles, but also those which expel air from the lungs. ”

“ Cut the heart into pieces, and each piece containing a ganglion will beat as before; the other pieces will be still. Beside this special cardiac system which influences the regular pulsations, there is the general nervous system, which accelerates and arrests these pulsations at every moment of our lives. The heart is thus connected with the general organism through the intervention of the great sensory apparatus. ”

“ The impulses of the sympathetic neurones, as indicated by their dominance over the digestive process, are capable of readily overwhelming the conditions established by neurones of the cranial division of the autonomic system. ”

“ Facility of motor discharge. Great concentration was necessary of course, but not sufficient. Persons in whom the flow of nervous energy tended to drain off over the nerves leading to the glands and the vascular system might betray great tension, not so much by movements as by a flow of perspiration (we have many excellent examples of this given by Manouvrier) [93] or by a violent beating of the heart, blushing and the like,—in short, by secretory and vasomotor effects. ”

“ There is, I take it, in the case a relief of sur-charged nerve-centres, which process would seem to be better described by the figure of a safety-valve arrangement.
It is not difficult to surmise why the liberated energy should follow this particular nervous route. There is no doubt that the motor apparatus, by the disturbances of which all such interruptions of the smooth flow of respiration are brought about, is very readily acted on by emotional agencies. Altered respiration, showing itself in altered vocalisation, is one of the first of the commonly recognised signs of emotional agitation ”

“ It is true that we are not conscious of the act of breathing. It would be an intolerable burden upon the mind if every breath required conscious attention. We could hardly attend to anything else.
That is no reason, however, why we should not regulate our breathing for our own benefit. Breathing, though an habitual organic act, is under the indirect control of the higher centers of the nervous system. ”

“ Liberation of neuron energy is correlative with active psychic and physical manifestations. Hence states of the nervous system corresponding to liberations of energy are designated as waking states. Restitution of expended energy or arrest of liberation of neuron energy goes hand in hand with passive conditions of the nervous system; hence states of restitution or arrest of energy are termed collectively sleeping states. ”

“ The nervous system consists of the fibres which carry currents inward, the organs of central redirection, and the fibres which carry them outward—sensation, direction, action. Since control means mental direction of this involuntary discharge of energy (directed muscular movement) , control of the muscles means development of will as well as of skill. To prevent or cut off the natural outflow of nervous energy results in fatigue and diseased nerves. Unrestrained and uncontrolled expenditure of nervous energy results in lawlessness and weakened will. ”

“ It decreases the irritability of the motor nerve, greatly affects the sensory 138ganglia of the central nervous system, preventing them from readily receiving impressions. Has a spinal tetanic action. It kills mainly by arrest of the heart. Increases the callory secretion. Has a stupifying action on the brain. Reduces the cardiac force and frequency. Temporarily increases arterial tension, but finally decreases it. ”

“ The waste of the nerve-centers having become such that the stimuli received from the external world no longer suffice to call forth from them adequate discharges, there results a diminished impulse to those internal organs which subserve nervous activity, including more especially the heart. ”

“ You may rest them by a change of the thought habit each day, by relaxation, by sleep, and by suggestions made in this book.
There are few advance danger signals shown by the nervous systems, and in this there is a marked difference between the nerves and the organic system.
If you abuse your stomach, head, heart, lungs, liver, kidneys or eyes, you have distress and pain.
The nervous energy is like a barrel of water; you can draw water from the faucet at the bottom until you have almost exhausted the contents.
Nature mends ordinary nerve waste each day, like the rains replenish the cistern. ”

“ To give a familiar instance, the action of the respiratory centers is suddenly inhibited by certain excitations of the sensory nerves, as we have all experienced on receiving the first splash of a cold shower-bath. In the cerebral sphere, inhibition of one tract by another is the mechanism which lies at the root of the higher exercise of our faculties."When we choose, for instance, or exercise will-power, the corresponding state of our nervous organism is one involving more or less complex inhibitions. ”

“ The slightest relaxation on the part of the nerves whose function is to cause slowing will lead to a prompt increase of rate, since the nerves that tend to cause increase are active all the time. Various things may bring about changes in the nervous balance governing the heart; chief of these are muscular activity and emotional disturbance. ”

“ Modifications in basic behavioral patterns and performance may occur as disruptions of rhythmic physiological phenomena, which are themselves the end product of interrelated functional activity in a number of physiological systems, such as the neuroendocrine, cardiovascular, and central nervous systems. ”

“ Hence if the sensorial power be lessened, while the quantity of stimulus remains the same as in nervous fever, the frequency of repetition of the arterial contractions may continue, but their force in respect to removing obstacles, as in promoting the circulation of the blood, or the velocity of each contraction, will be diminished, that is, the animal strength will be lessened. ”

“ So soon as the mental excitement is allayed, the excessive afflux of blood subsides, and the brain becomes fitted for sleep. But, if excitement be too far prolonged, the nutrition of the nervous centres suffers, and the regulative apparatus of the cerebral circulation becomes exhausted, so that the brain cannot rest, because its inhibitory centres have lost their power of control over the lower ganglia of the organ. The cerebro-spinal centres are then in a condition analogous to that of a locomotive engine on which the engineer can no longer regulate the production and distribution of steam. ”

“ This she repeatedly performed, so that her friends at a distance, as they lay in bed, heard distinctly the sounds. This fact being communicated to her physician, Dr. Kerner, he, by actual experiment and observation, confirmed it. This was not performed by her will, which was inactive in her somnambulic or cataleptic state, as well as her consciousness. Every nerve centre was in a most intimate rapport or relation with the mundane agencies, especially that which acts in conjunction with the nervous force, and holds every animal in a certain connection with every thing out of the organism. ”

“ It is also probable that the reflex centers can be made to give the regular orders to start work, not in the customary way by a message sent up to it from the organ, but by direct command of the lower parts of the brain, though not immediately by the cerebrum, or thinking portion. The functions of the sympathetic system are modified by the two pneumogastric nerves which start in the head and extend to the digestive organs, lungs, heart, liver, stomach and other organs. ”

“ All the motor nerves are convulsed with strong action, and the muscles they supply are wrought to the utmost, while all consciousness and control are entirely suspended. There is such an overwhelming supply of activity to the mere muscular system that the sources of that supply are soon exhausted, and the motion ceases for a time. Consciousness does not at once return fully, but the convulsions cease, and something like a sleep follows before the brain has its needed supply. ”

“ Sensations increase the action of the heart—slightly when they are slight; markedly when they are marked; and recent physiological inquiries imply not only that contraction of the heart is excited by every sensation, but also that the muscular fibres throughout the whole, vascular system, are at the same time more or less contracted. The respiratory muscles, too, are stimulated into greater activity by sensations. The rate of breathing is visibly and audibly augmented both by pleasurable and painful impressions on the nerves, when these reach any intensity. ”