Physiology

“ On this subject, physiology teaches the general fact that memory reposes upon a nervous property or power, sustained, like every other physical power, by nutrition, and having its alternations of exercise and rest. It also informs us that, like every other function, the plasticity may be stunted by inaction, and impaired by over-exertion.
As far as pure physiology is concerned, I invite everybody to reflect on one circumstance in particular. The human body is a great aggregate of organs or interests—muscles, digestion, respiration, senses, brain. ”

“ There are various means by which we gain important information respecting the Physiology of man. Plants aid us in understanding the minute structure of the human body, its circulation, and absorption. From inferior animals we learn much in respect to the workings of the different organs, as we call those parts of the system which have a particular duty to perform. In one of them, as in the foot of the frog, we can study the circulation of the blood; in another, we can study the action of the brain. ”

“ General Physiology, Cellular Physiology, the Energetics of Living Beings.—General physiology, as was taught by Pflüger and his school, claims to go deeper down than the apparatus, or the organ, or even the cell. As in the case of physics, general physiology endeavours to reach, and really does in many cases reach, as far as the molecule. ”

“ To understand the nature of disease we must understand health, and the understanding of the healthy body means the having a knowledge of its structure and of the way in which its manifold actions are performed, which is what is technically termed human anatomy and human physiology. The physiologist again must needs possess an acquaintance with physics and chemistry, inasmuch as physiology is, to a great extent, applied physics and chemistry. ”

“ By the useful and interesting study of physiology, we are enabled to define the construction of his system, to delineate the muscles, nerves, veins and fibres, and the complicated mass that forms the man, with all their separate dependencies upon each other. ”

“ Physiology embraces the properties and functions of the tissues and organs—the primary conditions of Growth and Development out of which rise the higher functions bringing the organism into active relation with the surrounding medium. ”

“ Everyone knows the doctor, and everyone knows that physiology deals with the ‘functions of different organs of the body’; but the public rarely meet the physiologist, except in the fanciful caricatures of his enemies, which though frequently personal are rarely accurate. ”

“ Physiology, in fact, has taken up its position in the explanation of the functional activity of the constituted organism—i.e., on a ground where intervene, as we shall show further on, no energies and no matter other than universal energies and matter. ”

“ Auscultation and percussion; observations of the healthy variations of the pulse, the tongue, the skin, and the various secretions, in as many healthy individuals, both adult and infant, as can be examined, compared, and recorded; the vital chemistry of the human tissues and secretions in health and disease; the modifying effects of temperament, heredity, idiosyncrasy, etc.—all this forms a department of human physiology, strangely neglected as a practical study, yet certainly of primary importance to the progress of medicine. ”

“ That understanding, when it is complete, will have been gained step by step through experiments on living animals, one of the first of which was Claude Bernard's research on vaso-motor nerves. [2]
There still remains the question, What good does physiology bring to mankind? Of the value of physiology as a not insignificant segment of the circle of universal knowledge, nothing need be said; where saying aught is necessary, it would be useless. Nor need much be said concerning the practical value of physiology as a basis for the conduct of life. ”

“ Medicine was the foster-mother of chemistry, because it has to do with the preparation of drugs and the detection of poisons; of botany, because it enabled the physician to recognize medicinal herbs; of comparative anatomy and physiology, because the man who studied human anatomy and physiology for purely medical purposes was led to extend his studies to the rest of the animal world. ”

“ From a physiological point of view, those metaphysical phenomena of thought, consciousness, and intelligence, which serve for the various manifestations of the human soul, are nothing but ordinary vital phenomena, and can result from nothing but the action of the organ that expresses them. We shall show that, in fact, the physiology of the brain, like that of all the other bodily organs, is deduced from anatomical observations, from experiments conducted physiologically, and from the teachings of pathological anatomy. ”

“ In the fifth place, modern physiology investigates the relation between physical and psychical phenomena, on the assumption that molecular changes in definite portions of nervous matter stand in the relation of necessary antecedents to definite mental states and operations. ”

“ The facts and principles are then applied to everyday life. Anatomy and pure physiology make clear and fix hygienic points, while applied physiology lends interest to the otherwise dry facts of physiology and anatomy. From the great range of the science there are included only those subjects which are directly concerned in the growth and development of children. ”

“ It is of infinitely more consequence to understand the basic principles of digestion and the proper combination of foods, or to understand thoroughly the baneful effects of sleeping in a badly ventilated room, than to be the greatest living expert in conic sections. Practical physiology is the crying need of the times, especially for our children, if we expect them to be well developed—mentally morally and physically. ”

“ All the experiments in physiology consist practically in the production of so many pathological conditions and states. When the physiologist makes injections, sections and stimulations by various agencies, what else does he effect if not the production of the pathological, in order to learn the physiological action of the various tissues and organs? ”

“ It is sound physiology, as well as good morals and manners, to cease from the usual routine of six days of mental or physical work, and rest both the mind and the body on the seventh. Those who have succeeded best in what they have undertaken, and who have enjoyed sound health during a long and useful life, have studiously lived up to the mandates of this great physiological law. ”

“ But one of the most striking differences between ancient and modern physiological science, and one of the chief reasons of the rapid progress of physiology in the last half-century, lies in the introduction of exact quantitative determinations into physiological experimentation and observation. ”

“ The wide bearing and importance of the truths derived from physiology will become more and more apparent, as we examine another branch of the subject, and ascertain from an observation of facts around us, how far the present relations of men and women in civilized countries, are based upon sound principles of physiology. ”

“ The vital activities taking place in the bodies of higher animals are too complicated and too intricately mixed to admit of clear analysis, and, long ago, physiologists learned that the quest for explanations of living activities lay along the line of investigating them in their most rudimentary expression. The practical recognition of this is seen in our recent text-books upon human physiology, which commonly begin with discussions of the life of these simplest organisms. ”

“ We discuss elsewhere the return of vitalism in physiology—that is, the reassertion of a principle of life behind the chemical and physical forces of the human organism regulating it, supplying energy, occasionally enabling it to transcend the ordinary laws of osmosis, or the diffusion of gases. The main seat of this principle of life is in the central nervous system and especially in the cerebral cortex. ”

“ The physiology of the senses and sense-organs of animals is studied as preliminary to the psychical or mental accompaniments of affections of those organs, which are styled explosive disturbances in the brain or other aggregated mass of nerve-cells. ”

“ But if we consider this great function in the important relations of nutrition, secretions, exhalations, for which they furnish the materials, of the general stimulus it carries to all parts, and which is indispensable to the support of life, of the introduction of foreign fluids in the body of the animal, and of the change of these fluids into its own substance ”

“ So the vital property is the primum mobile to which we must ascend, whether we consider the phenomena of respiration, of digestion, of secretion, circulation, inflammation, fevers, &c.—In giving existence to every body, nature has imprinted upon it a certain number of properties, that particularly characterize it, and by means of which it contributes in its own manner, to all the phenomena that are developed, succeed, and continually connect themselves in the universe. ”

“ The first problem is internal and includes the so-called vital processes, known as digestion, circulation, respiration, and excretion. The second problem is external, as it were, and includes the work of the external organs—the organs of motion and of locomotion and the organs of special sense. These problems are closely related, since they are the two divisions of the one problem of maintaining life. Neither can be considered independently of the other. ”

“ As we approach man, in the scale of beings, we find that the organs multiply, and the functions become more complete. The function of motion, the instruments of which—the muscles and bones—have been considered in former chapters, and all the other animal functions of man, depend upon the set of organs known as the nervous system.
4. The nervous tissues, of what composed? When examined by the aid of the microscope? The white substance? The gray substance?
4. The Nervous System.—The intimate structure of this system differs from any tissue which we have before examined. ”

“ The sense organs and the nervous system are just as deeply concerned, therefore, in avoiding harm as in finding food materials, and it is as important for them to do their work well in the one case as in the other. When we think of the activities of animals, for whatever purpose they are carried on, we must think of them as made up of the combined actions of the muscles, the nerves, and the sense organs, and not of any of them working by themselves. ”

“ It is necessary, therefore, that the body have some means either of checking the development of the organisms or of neutralizing the poisons which they produce. The body has this power, and the machinery for it consists very largely of substances or structures in the body fluids. ”

“ A physician’s physiology has much the same relation to his power of healing as a cleric’s divinity has to his power of influencing conduct. ”

“ A number of organs working together for the same purpose form a system. The chief systems of the body are the digestive system, the circulatory system, the respiratory system, the muscular system, and the nervous system. ”

“ By means of the special sensations, a knowledge of the physical surroundings of the body is gained, and through the organic sensations the needs of the body and the state of the various organs are indicated. ”

“ We shall be easily convinced upon reflection, that we cannot precisely estimate the immense influence of the vital properties in the physiological sciences, before we have considered these properties in the point of view in which I have presented them. ”

“ There is a trinity in our anatomy. Three systems, to which all the organs are directly or indirectly subsidiary, divide and control the body. First, there is the nutritive system, composed of stomach, intestines, liver, pancreas, glands, and vessels, by which food is elaborated, effete matter removed, the blood manufactured, and the whole organization nourished. This is the commissariat. Secondly, there is the nervous system, which co-ordinates all the organs and functions; which enables man to entertain relations with the world around him, and with his fellows ”

“ Life is carried on by certain great functions, which we call Respiration, Digestion, Circulation, and Secretion, all of which proceed under the impulse of the involuntary nerves; all of them are, however, dependent upon the voluntary nerves and muscles for their proper opera­tion. Breathing requires exercise, change of air and position; diges­tion demands the procuring and preparing of the food; circulation can only be brisk when the body is in motion: and all these motions are necessary to a proper and healthy secretion of the fluids and solids taken into the stomach. ”

“ How did the substance reach it which constituted its growth? Every particle of matter that reaches it to 18form its brain, its nerves, its heart, its lungs, its blood, its bones and sinews, was prepared in the maternal organism, and was carried to it through the medium of her blood. Whatever is received into her system, in the shape of food, drink, air, and various gases, and which goes to nourish her brain, heart, nerves, and other organs, and keep them in healthful activity, must go to form the corresponding portions of the child’s body. ”