Sweat gland

“ It Removes Waste.—The sweat glands and ducts are constantly at work removing from the blood particles which have been worn out and can be of no further use. If we get very [Pg 86] warm, or if we run or work very hard, the skin becomes wet with sweat. In a little while, if we stop to rest, the sweat is all gone. What becomes of it? You say it dries up, which means that it has passed off into the air. Sweating is going on all the time, but we do not sweat so much when we are quiet and are not too warm, and so the sweat dries up as fast as it is produced, and we do not see it. ”

“ The sweat glands are under the control of certain nerve fibers originating in the spinal cord, and are not necessarily excited to action by an increased flow of blood through the skin. In other words, the sweat glands may be stimulated to increased action both by an increased flow of blood, and also by reflex action upon the vaso-dilator nerves of the parts. These two agencies, while working in harmony through the vaso-dilators, produce phenomena which are essentially independent of each other. Thus a strong emotion, like fear, may cause a profuse sweat to break out, with cold, pallid skin. ”

“ You cannot always help breaking your skin, but you can always wash the break with soap and water, and put a clean cloth over it to keep out germs.
The work of the sweat glands
The work of the little sweat glands is very important to your health. These glands are just as important as the kidneys, and if they did not do their work, you would die very quickly. If your body is covered with dirt, the work of these glands is seriously interfered with; and when the sweat glands are not doing their full amount of work, the kidneys must do more than their share. ”

“ The sweat glands are twisted and coiled-up tubes, occupying the true skin and the layer of tissue beneath. They open upon pores, almost invisible to the naked eye. When we are at rest the flow of perspiration, though constant, is seldom so free that it does not evaporate almost as rapidly as it exudes, so that the skin is only kept pleasantly moist; but during exercise, especially in warm weather, the cutaneous surface becomes covered with drops of fluid. ”

“ Besides the sweat glands there are glands which exude fatty substances upon the skin, keeping it suitably lubricated and somewhat impervious to water. In some animals this secretion is so abundant that the skin cannot become wet in swimming. ”

“ The sweat glands, as we have already seen, make up part of the service of the removal of waste in that they help to carry away water from the body. To a very slight extent, but much slighter than is commonly believed, they get rid also of waste products of cell activity; for example ammonia, which is one such product, can frequently be detected in the sweat by its odor; practically, however, the importance of sweat glands is not in their discharge of waste organic substances, but only in their discharge of water. ”

“ Under pathological conditions, sugar urea and other substances are found. The secretion of sweat is constantly going on, the activity of the sweat-glands being under control of the central nervous system. ”

“ The sweat glands discharge on the average from one and one-half to two pounds of perspiration per day, more in hot weather and much less when it is cool. They are distributed over the whole external surface of the body. ”

“ In order that the skin may perform its functions properly, it must be perfectly clean, the pores must be kept open, and the sweat glands free to throw off all the effete matter and prevent its accumulation within the system. While soap and water are necessary and helpful, free perspiration induced by vigorous bodily exercise or artificial heat will also enable the glands to cast off the more solid substances which accumulate at the bottom. ”

“ They have a system of sweat glands, but this is not so highly organized as it is in man, so that their physical heat regulation is brought about not only by evaporation of sweat, but also to a very great extent by water evaporated from the lungs and mouth through increased respiration. ”

“ With few exceptions every portion of the skin is provided with sweat glands, but they are not equally distributed over the body. They are fewest in the back and neck, where it is estimated they average 400 to the square inch. They are thickest in the palms of the hands, where they amount to nearly 3000 to each square inch. These minute openings occur in the ridges of the skin, and may be easily seen with a hand lens. The length of a tube when straightened is about 1/4 of an inch. ”

“ People are likely to think of the skin as being simply a covering for the body, whereas, in reality, it is a very complicated and active organ which helps to regulate the body temperature and constantly throws off impurities, just as the kidneys do. This latter function is performed by the sweat glands which open upon the surface of the skin as the “pores,” and we are told that in all there are some twenty-eight miles of these tiny tube-like structures in the skin. These glands should be, and usually are, constantly active ”

“ The sweat glands of the horse, like those of man, are composed of simple tubes, which extend down through the cuticle and dermis in a spiral manner, and are coiled into balls in the deeper layer of the true skin. In addition to their importance in throwing offensive waste products out of the system, these glands tend to cool the skin and the entire economy of the animal through the evaporation of their watery secretion. ”

“ It is so true that it is not the suppression of the sweat which is dangerous, but the alteration of the vital forces of the skin which sweats, that many kinds, as the sweat of phthisis, are not so injurious when they cease for a time ”

“ The liquid sweat, which in the ordinary state of the body is only given off in sufficient amount to prevent the skin from becoming over-dry, is secreted by the sudoriferous glands, whose ducts terminate in large numbers on the surface at every part. There is in the third place an oily material, formed for a similar purpose by the sebaceous glands, which are widely distributed, but fewer in number than the last. ”

“ Can any one explain how these partial sweats should relieve the difficulty of breathing in anasarca, but by supposing that the pulmonary branch of absorbents drank up the fluid in the cavity of the thorax, or in the cells of the lungs, and threw it on the skin, by the retrograde motions of the cutaneous branch? for, if we could suppose, that the increased action of the cutaneous glands or capillaries poured upon the skin this fluid, previously absorbed from the lungs; why is not the whole surface of the body covered with sweat? why is not the skin warm? ”

“ Besides the insensible transpiration and the sweat, which are thrown out by the skin, this organ is constantly lubricated by an oily fluid, which occasions, when coming out of a bath, the water with which it does not unite, to collect in small drops upon the body, which greases the linen when it remains too long in contact with the skin, catches the dust that is floating in the air, makes, it remain upon the skin, and retains many foreign substances coming with the sweat from without or within. ”

“ Thirdly, The peculiar alteration in the fundamental composition of organic matter in rheumatic diseases, in consequence of which volatile acids of a strange odour are prevalent in the sweat, and urine, and animal excretions. The English Sweating Sickness exhibits also this result of morbid activity in a greater and more striking manner than any other disease. Nor can we regard the tendency to putridity, which has been observed, as any thing but an increased degree of this condition. ”

“ Just lately a germ has been discovered which has the power of rendering the perspiration offensive in a very short time. Usually the sweat is perfectly inodorous when exuded, but in some families a condition known as bromhydrosis obtains, in which the perspiration is of an offensive odour. In some diseases, where excessive perspiration occurs, the sweat soon develops an offensive smell, doubtless due to the machinations of the germ mentioned above. The commonest diseases in which excessive sweating occurs are ague, phthisis, and rheumatic fever. ”

“ The sweat serves to keep the skin moist and in good condition, to remove outworn and poisonous or irritating matters, and to regulate the temperature. As a rule it evaporates upon reaching the surface, in which case it is known as invisible or insensible perspiration, but if conditions of the atmosphere are not favorable to prompt evaporation, as when the air is damp, the skin becomes damp and there is visible perspiration. ”

“ The sweat is a turbid, saltish fluid with a feeble but characteristic odor due to certain volatile fatty acids. Urea is always present in small quantities, and its proportion may be largely increased when there is deficiency of elimination by the kidneys. Thus it is often observed that the sweat is more abundant when the kidneys are inactive, and the reverse is true. ”

“ This early and seasonable measure will, in many cases, put a stop to the disease, especially if the patient is thrown into a sweat immediately after the bowels have been thus thoroughly evacuated. It is of great service in this disease to promote free perspiration, and even a plentiful sweat, which may be effected with great advantage by giving, at bed time, a medicine composed of opium, ipecacuana, and a little neutral salt, accompanying it with plentiful warm dilution. Nothing tends more to relieve griping and tenesmus than a general, warm moisture on the skin. ”

“ WHEN Persons grew no better for Sweating, but weaker, and the Distemper higher, it was judged fatal.
FOR after Nature had made such an Effort to expel the Venom to no Purpose, all Hopes of Recovery could not but vanish. A great Expence of Spirit, and a general Decay of Strength, must be the Consequence of such a Wast; and a Continuance of Sweat likewise brings on a dangerous Colliquatation, or is a Sign of it; and those hot sharp Sweats, which vesicate the Skin, are also to be suspected: Moreover, it is very hazardous when cold Sweats come after such hot ones. ”

“ Until then sweats had not been very copious; for, other things being equal, we may say that children sweat less in general than adults, and that the residue of their nutrition passes rather by the urine, which is probably the reason why they are so remarkably disposed to calculi. Beyond the twentieth year we begin to sweat more, and until old age, especially in summer, the fluids appear to go out in this way. ”

“ For example, there are many people who feel very much better after profuse perspiration, and as sweat appears to contain little but water and a few salts, it is not improbable that the improvement in their condition is due rather to the internal secretion from the skin than to the elimination effected by the sweat. ”

“ The flow may be intermittent, appearing at intervals from a few hours to months. Sometimes the discharge is connected with skin diseases, but often the skin is unaffected. Examples have been found at every age and in both sexes, but this sweat is commoner in women. ”