Human physiology

“ 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. ”

“ What I would insist upon is, that we should endeavour to make ourselves thoroughly acquainted with the nature and variations of healthy human physiology before we are perplexed with the changes of pathology. ”

“ 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. ”

“ 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. ”

“ New secrets of physiology may be revealed, deeply affecting human nature in its innermost recesses. The standard of health may be raised and the lives of men prolonged by sanitary and medical knowledge. ”

“ 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. ”

“ 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. ”

“ What are all the organs and tissues for, and what takes place within the parts that are actually alive? Physiology attempts to answer questions of this nature. It therefore stands in contrast with anatomy and is supplementary to it. The activities of the body are varied and depend on life for their manifestation — they may be called vital activities. Physiology embraces a study of them all. This subject began to attract the attention of the ancient medical men, who wished to fathom the activities of the body in order to heal it in disease. ”

“ 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. ”

“ Simple physiology, as it is usually known, treats of the activities or the functions of the organs, such as the brain, stomach, heart, muscles, spinal cord, lungs, kidneys, etc., which may be considered as carrying on independent processes, or in their vitally coordinated, intimate, mutual relations. But, in contradistinction to this conception of the physiology of organs, there is also a more comprehensive physiology of animal organisms, which may be properly termed universal physiology. ”

“ Don’t you know that physiologists themselves admit that the human body is composed of eighty-five per cent water and fifteen per cent ordinary salts? Can such a combination have intelligence and sensation? Do you still believe that life is dependent upon lungs, stomach, or liver? ”

“ 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. ”

“ 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. ”

“ What Physiology should Teach us. The study of physiology is not only interesting, but it is also extremely useful. Every reasonable person should not only wish to acquire the knowledge how best to protect and preserve his body, but should feel a certain profound respect for an organism so wonderful and so perfect as his physical frame. For our bodies are indeed not ourselves, but the frames that contain us,—the ships in which we, the real selves, are borne over the sea of life. ”

“ 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. ”

“ By our observation of the human organism, in relation both to the different functions of the soul and to the different main organic systems, we further recognized the fact that the ways in which body and soul are interrelated are polarically opposite in the region of the brain and nerves and in the region of the metabolic processes, which again results in two polarically opposite activities of the soul, mental on the one hand, and volitional on the other. ”

“ 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. ”

“ When those substances are wanting, whose function in the organism is to support the process of respiration, when the diseased organs are incapable of performing their proper function of producing these substances, when they have lost the power of transforming the food into that shape in which it may, by entering into combination with the oxygen of the air, protect the system from its influence, then, the substance of the organs themselves, the fat of the body, the substance of the muscles, the nerves, and the brain, are unavoidably consumed. ”

“ 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. ”

“ 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. ”

“ There are, besides, scavengers and cleaners to pick up things no longer wanted anywhere and to throw them out of the body. Thus the blood is kept pure as well as fresh. Through the blood thus ever brought to them, each part does its work: the muscle contracts, the brain feels and wills, the nerves carry the feeling and the willing, and the other organs of the body do their work too, and thus the whole body is kept alive and well. ”

“ 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 ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ But otherwise it may be argued that, since changes of structure and composition, though concomitants of muscular and nervous actions, are not the muscular and nervous actions themselves, the definite excludes the more visible movements with which our idea of life is most associated; and further that, in describing vital changes as a series, it scarcely includes the fact that many of them, as Nutrition, Circulation, Respiration, and Secretion, in their many subdivisions, go on simultaneously. ”

“ 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. ”

“ All of the vital functions are active; the large chest-room, the vigorous heart, the firm muscles, insure a bodily activity that keeps the operations of organic life in unconscious and easy motion. Digestion, assimilation, excretion, and elimination, work in harmony and with vigor.
Mentally, this type is the reflection of its physical traits. The rich blood, by its active circulation through the brain, causes vivid and active mental action. The general cast of the mind is never gloomy. ”

“ 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. ”

“ Now, all who are acquainted with physiology know perfectly well that the mind cannot be properly unfolded unless the organism through which it is manifested be in a healthy condition, so as to be enabled to register the impressions made upon it by external circumstances. ”

“ So wonderful is the human organism, however, that the process is carried on perfectly without our consciousness or volition except under abnormal conditions.
"Food and air are the first essentials of this restoration. In-directly the perfect working of all the bodily organs contributes to the process—especially deepened breathing, heightened pulse, and increase of bodily volume due to the expansion of the blood vessels running just beneath the skin. ”

“ Not only the bodily factors like nutrition and circulation and sexual functions have a thousandfold influence on the psychophysical processes, and these in turn change the vegetative functions of the body, but especially the other parts of the brain and nervous system can be affected in most different ways. ”

“ 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. ”

“ 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 ”