Organ system

“ First, other congeries of glands occupy but a particular part of the system, or constitute a particular organ, as the liver, or kidneys; but those glands, which secrete the mucus, and perspirable matter, which are called capillaries, are of very great extent; they receive the blood from the arteries, separate from it the mucus, which lines every cell, and covers every cavity of body; and the perspirable matter, which softens and lubricates the whole surface of the skin, and the more extensive surface of the air-vessels, which compose the lungs. ”

“ So many unknown conditions exist in such an organ that it is impossible to say what tissue is acted on primarily, whether the nervous system on the one hand, or the glandular and muscular tissues on the other. There are, however, two indicators in the intestine by which the comparative actions of substances can be studied, namely, the muscular movements, and the secretion of fluid, both of which by various chemical substances may be increased or lessened ”

“ They could affect only one or certain organs, because by selection only the chosen organ or organs knew the code, as it were. The chemical system is much the older system, and preceded the nerve system by aeons of time. The whole system, viscera, visceral nerves and the endocrines gradually united into a complete autonomous organism within the organism, and as such functions as the vegetative apparatus. ”

“ The main systems of organs are, in order of importance, the nervous and muscular, the digestive, the circulatory, and the respiratory. Each organ or system of organs may have many forms. If any form of any organ could exist in combination with any form of all the others there would be an enormous number of combinations theoretically possible. But these combinations do not all exist in Nature, for organs are not merely assembled (rapprochés) , but act upon one another, and act all together for a common end. ”

“ When an organ is exercised properly, there is an increased blood supply to it, and, consequently, stimulated nutrition and growth in various parts, such as in the muscular, nervous or other tissues.
When an organ is disused there is diminished blood supply, and, consequently, diminished growth and functional capacity. In man it is known that certain activities, such as coal-heaving, shoemaking, etc., produce recognizable effects upon the muscular system, the skeleton, and other parts of the body. ”

“ The idea of an entirely specific structure for each cell of an organ—both from the chemical and physical points of view—is based not only on the supposition that, without such a notion, the special duties and functions of the separate cells of the body would appear incomprehensible, but, above all, on the above-mentioned fact that definite secretions given off by particular organs act constantly and only upon cells of a definite system. ”

“ The digestive system includes every organ, function and process concerned with the utilization of food-stuffs, from the moment of their entrance into the mouth, their preparation in the canal, assimilation with the tissues, their employment therein, up to their excretion or expulsion in the form of waste. Each portion resembles a link of a continuous chain; each link depends upon the integrity of the others, the weakening or breaking of one straining or making impotent the chain as a whole. ”

“ Reflecting, now, on the organic and physico-chemical conditions required for the support of life and the discharge of its functions, we find that they are the same in the brain as in all the other organs. The blood acts on the anatomical elements of all the tissues by supplying their indispensable conditions of nutrition, temperature, and humidity. When a diminished supply of blood flows to any organ, its activity of function declines, and the organ rests; but if the blood is quite cut off, the elementary properties of the tissue slowly change, while at the same time its function perishes. ”

“ This distinction is diagnostic but not perfectly characteristic; that is, we may safely classify as an animal any organism in which we find a definite, sharply-limited body, and complicated internal viscera, such as a digestive tract, respiratory organs, blood-vessels, internal reproductive organs, and a nervous system and sense-organs; while we may, with almost equal safety, refer to the vegetable kingdom an organism in which the nervous, sensory, and circulating organs are wanting, and the processes of absorption and respiration take place through the outer surface. ”

“ 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 ”

“ The blood contains the materials of all the secretions, of the nutrition of all the organs, and of all the exhalations. Each gland draws from this common reservoir what is necessary to its secretion, as each organ does what is proper for its nutrition, and as each serous surface does what is suitable for its exhalation. Now it is by its organic sensibility that each living part of the body distinguishes what its functions require. ”

“ Cells make up the body, and do its work. Some are employed to construct the skeleton, others are used to form the organs which move the body; liver-cells secrete bile, and the cells in the kidneys separate poisonous matters from the blood in order that they may be expelled from the system. ”

“ If this position be true we are warranted and justified in the conclusion that the germs necessary to form blood vessels and other parts of the body must look to the liver for the fluids in which they would expect to construct in form and size. It seems to be nature's chemical laboratory, in which are prepared by receiving chemical qualities and quantities to suit the formation of hard and soft substances, which are to become the parts and the whole of any organ, gland, muscle, nerve, cell, veins and arteries. ”

“ As regards the physiology of particular organs, attention has been, in recent years, attracted in a marked degree to two subjects: the so-called internal secretions of certain glands and the arrangement and actions of the nerve-cells and fibers which make up the central nervous system.
By an internal secretion we mean a substance or substances formed by a gland and taken up from it by the blood or lymph. An ordinary external secretion is discharged by a special duct into the proper receptacle, bile, for example, into the gall-bladder, and ultimately into the intestine ”

“ whilst the study a posteriori of the distribution of consciousness shows it to be exactly such as we might expect in an organ added for the sake of steering a nervous system grown too complex to regulate itself. ”

“ As a rule, those which inhabit a temporary host install themselves in a closed organ; in the muscles, the heart, or the lobes of the brain; those, on the contrary, which have arrived at their destination, and which, unlike the preceding, have a family, occupy the stomach, with its dependencies the digestive passages, the lungs, the nasal fossæ, the kidneys, in a word, all the organs which are in direct communication with the exterior, in order to leave a place of issue for their progeny. ”

“ As the body is composed of individual organs, and each organ of separate tissues, so each tissue is made up of minute cells. Each cell is a little world by itself, too small to be seen by the naked eye, but open to the microscope. It has its own form and constitution as much as a special organ in the body. It absorbs from the blood such food as suits its purposes. Moreover, the number of cells in an organ is as constant as the number of organs. As the organs expand with the growth of the body, so the cells of each tissue enlarge, but shrink again with age and the decline of life. ”

“ The nutritive matter is driven to all parts of the body, with the blood, through a system of arteries and veins, by a pulsating heart, and during a part of its course the blood passes through respiratory organs, where it is aerated by contact with the air or water. The waste products are excreted from the blood by renal organs, and the organs of reproduction are extremely complicated and highly specialized. ”

“ The lungs are the principal organs for the function of breathing; the heart, arteries and veins are the organs which have for their function the circulation of the blood; the principal organ concerned in the digestion of food is the alimentary canal, the function of seeing is performed by the organs of sight, the eyes, and so one might continue the catalogue of all the organs of the body and of all the functions performed by the animal. ”

“ Each organ is to every other as an excreting organ. In other words, to insure perfect health, every tissue, bone, nerve, tendon, or muscle should take from the blood certain materials and return to it certain others. To do this every organ must or ought to have its period of activity and of rest, so as to keep the vital fluid in a proper state to nourish every other part. ”

“ Every part of our organism is the subject of continual change. The flesh of the arm to-day is not precisely the same flesh as yesterday; some of its cells have been used up, dissolved, and carried away by the blood, and have been cast out of the system through the kidneys or bowels, whilst their places have been supplied by new molecules formed by digestive changes from the food taken into the stomach. ”

“ The cells must function quickly to prevent disharmonious substances from entering the circulation. To ensure the proper discharge of a duty so important to the organism, the liver is placed between the intestines and other organs. Within this important organ the blood, still laden with the absorbed and partly metamorphosed food-stuffs, comes into contact with the liver cells. This material is once more thoroughly sifted, and the blood is finally discharged into the general circulation, freed from all substances that would be out of harmony with the body and the blood. ”

“ While the quantity of blood supplied to other organs is affected, its quality also is in some cases affected. Each organ, or at any rate each class of organs, has special nutrition—abstracts from the blood a proportion of ingredients different from that abstracted by other organs or classes of organs. ”

“ All cells need food and oxygen. Some must have this carried to them. A system of tubes carries blood which carries food and oxygen. Food must be prepared to get into the blood. Digestive system: mouth, teeth, stomach, intestines, glands, and digestive juices. Uses of above in preparing food to pass into the blood. Absorption of food into the blood. How oxygen gets to the cells. Nose, throat, windpipe, lungs; blood goes to lungs and carries away oxygen. Excretion. Cells give up wastes to blood and these wastes taken out of blood by kidneys and other glands and passed out of body. ”

“ If you should prick your finger and extract a drop of your own blood, and examine it under a microscope, you would make the fascinating discovery that it is the home of living creatures, each having a separate and independent existence of its own. In a single ounce of blood there are more of these organ [Pg 22] isms than there are human beings upon the face of the globe. These organisms are of many kinds, but they divide themselves into two main groups, known as the red corpuscles and the white. ”

“ One servant or clerk does one kind of work while another does something entirely different. Each portion of the body does a different kind of work. Each one of these parts doing a particular work is called an organ. The stomach is an organ to prepare food and the heart is an organ for sending the blood through the body.
Fig. 5 —On the left are shown the branching tubes which carry blood to all parts of the body; on the right are the brain, spinal cord, and nerves which direct the work of the organs. ”

“ Through this faculty of the lining tissue of the blood-vessels, the size of the lumen and the direction of branching are so regulated as to oppose the least possible resistance to the flow of the blood.
" (2) The faculty possessed by the endothelium of the capillaries of each organ of adapting itself qualitatively to the particular metabolism of the organ." This adaptedness of the capillaries is, however, more usually an inherited state, i.e., brought about in the first period of development. ”

“ The similarity of the texture of the brain to that of the pancreas, and some other glands of the body, has induced the inquirers into this subject to believe, that a fluid, perhaps much more subtile than the electric aura, is separated from the blood by that organ for the purposes of motion and sensation. ”

“ These organs are,—the lungs, which throw off a portion of useless matter when the blood is purified; the kidneys, which secrete liquids that pass into the bladder, and are thrown out from the body by that organ; and the intestines, which carry off the useless and more solid parts of the food, after the lacteals have drawn off the chyle. In addition to these organs, the skin has a similar duty to perform; and as it has [Pg 92] so much larger a supply of blood, it is the chief organ in relieving the body of the useless and noxious parts of the materials which are taken for food. ”

“ Increased action of any organs means an increased determination of blood to that organ; an increased determination of blood to any organ means increased action of the old that organ, hence we have a vicious circle established, which at first causes functional disturbances and later anatomical change. ”