An atlas of anatomy, or, Pictures of the human body in twenty-four quartro coloured plates comprising one hundred separate figures, with descriptive Letterpress / by Fenwick Miller.
- Miller, Florence Fenwick, 1854-1935.
- Date:
- 1879
Licence: Public Domain Mark
Credit: An atlas of anatomy, or, Pictures of the human body in twenty-four quartro coloured plates comprising one hundred separate figures, with descriptive Letterpress / by Fenwick Miller. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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![muscles of all shapes and of all sizes, and running in the most various directions ; but when we come to study those muscles in action, we find that every single one, from the tiniest one in the face to the greatest one in the thigh, is just the shape and the strength that it ought to be for its own special work. Every one Las its office to perform, and is precisely suited to perform it. Nor are the muscles seen in this figure all that the l.)ody possesses. This is only the superficial layer, and in many parts (as Fig. B serves to illustrate) the external layer must be quite removed to show the equally powerful and equally needful second or third layers beneath. The muscles are fastened on to the bones in the elaborate and wonderful manner shown in C, D, E, F of this Plate, as well as in A. The ends of the muscles pass almost im- perceptibly into tough, white cords, called tendons, which are attached to the bones. In cases where several muscles are fastened close beside each other, or where they are intermingled one with another (as in the hand, where many muscles are needed to supply the power for the infinite variety of movements of which that meml.ier is capable), the various tendons and sheaths which bind them into place are so complicated, and yet so perfect, that they arouse our wonder and admii'ation. Thus, in the hand and foot, which may be studied care- fully in the Plate before us, the tendons are very numerous and carefully arranged. The muscles which bend (or flex) and open (or extend) the fingers, are situated in the lower arm—the extensor muscles at the back, and the flexors at the front. In the same situation are also the muscles which move the whole of the lower arm in certain direc- tions, and those which flex and extend the wrist. Now the tendons of the muscles which move the fingers have a long distance to run (see Fig. A, 23, 2 i, 25), so that if they were not carefully bound down, they would start out in every direction when the muscles acted, in the most ex- traordinary manner. The fingers are flexed by two distinct muscles, which lie on the front of the forearm (as the aim below the elbow is called), one below the other. In the right forearm of Fig. A the second or under layer of muscle is shown ; and the large muscle marked 23, which is seen to di-sdde into four tendons, is the deep flexor of the fingers. Anatomists always use Latin or Greek terms ; and as any one who means to study Anatomy in detail must learn the Latin names, the muscles are described in that language in the Index to the Plates. The name which I have just given to this muscle is merely a literal trans- lation of the name that will be found there. The deep flexor of the fingers has the end of its tendons attached to the tip of the fingers in front, as shown in Fig. A. The upper flexor of the fingers has its tendons attached to the second finger-joint (Fig. C, 6). Now these tendons are seen to be held down first of all at the wrist, by the anterior and posterior annular ligaments, which pass around the wrist like a broad bracelet. In the palm of the hand is another portion of fibrous tissue, which equally firmly holds the tendons down beneath it, and which is removed in the picture to show the tendons. Finally, the. complex bandage of ligaments around the tendons on the fingers themselves can be studied in Fig. C, where the sheath investing the tendons is left entire on the Uttle and the third fingers, but removed from the first and second fingers, to show the attachment of the tendons of the upper flexor (sublimis digitorum). It is not possible, in the brief space at my disposal, to thus describe in detail the arrangements of other muscles. But the reader will understand that this is merely an in- stance of the ver}- elaborate way in which the muscles are arranged and suited to their use in every part of the body. A careful study of the several figures on Plates VII. VIII. Work of Bones and Muscles. The offices of bones and muscles are, broadly, two in number—viz. to jyroied the delicate vital organs, and to pro- duce motion and locomotion. That they perform the office first mentioned, is seen at a glance. Tlie brain rests fully enclosed in the bones of the skull, and further protected by muscles. The ribs enclose the heart and lungs; the rectus, the obliquus, and other muscles, close in the cavity of the abdomen, and protect the important organs that lie there (see Plates XIV. XV.), and the pehas shares in the same service. But to under- stand how the muscles and bones produce motion and locomotion, we must study the functions of muscular tissue. Plate IX. Fig. D represents a muscular fibre, treated with an acid which has caused its minute structure to become visible, and immensely magnified ; and Fig. E shows a muscular fibre of quite a ditterent kind. You will notice at a glance that D is marked with stripes both longitudinally and running round, the latter being rather the more distinctly seen, while E is perfectly smooth, and contains a nucleated cell in its midst. Physiological research has shown that the striated (/.«. striped) muscular fibre composes all the muscles that are under the control of the will, which includes, of course, all the muscles of the limbs ; we move our limbs by our volition. The unstriped fibres are found in the gullet, in the coats of the blood-vessels, and in other situations where muscular action takes place without the order of the will. Striped muscular tissue is therefore often called roluntary, and un- striped involuntary muscle. Fig. D, 1, shows at the torn end of the fibre that the fibre really consists of a great number of smaller fibrils ; while at 5 it is seen that the fibre readily splits up into discs, which are composed of numerous little rounded particles. Each fibre is about ^-g- of an inch in breadth ; each of its fibrils is only about tttwo to x^luo o^ ''^■^ i*^!* across—a smallness cjuite unimaginable to anybody not accustomed to microscopic work. The fibrils are found to be fastened together to form a fibre by a fine membrane (not seen in the figure), called the sarcolemma. Then a number of fibres are in like manner bound together by a fine membrane into bundles, and a number of these bundles are again fastened up with each other to form a muscle. To carefully dissect an orange will give one some idea of this repeated binding up of bundles to form one whole. The muscles are plentifully supplied with blood-vessels, which run aU through amongst the fibres, forming a net- work around them, but never penetrating through the sar- colemma which binds together the fibrils. Nerves also enter the nniscles, but they are so exceed- ingly delicate that it is still far from certain how they end. Fig. C shows what is lielieved to be the method of the ter- mination of nerve in a voluntary muscular fibre. This same figure, C of Plate IX., also introduces us to the action of the muscles whose structure we have now fully studied. The special power peculiar to muscular tissue is that of contraction. AVhen a muscle contracts, it becomes shorter and thicker. If you lay one hand upon the biceps muscle (Plate VII. Fig. A, 1) of the opposite arm, and then draw up the lower part of the arm towards the shoulder, you distinctly feel the biceps grow thicker and shorter under your hand. And by looking at it in the Plate just named, you can see at once that, since one end of the muscle is fixed to the shoulder, and the other end to the forearm just below the elbow-joint, the efi'ect of its growing thicker and shorter must needs be to draw up the forearm. The entire muscle contracts by the contraction of each of its fibres. ]\Iost probably, every one of the tiny particles into](https://iiif.wellcomecollection.org/image/b21212922_0014.jp2/full/800%2C/0/default.jpg)
