Backbone

“ When you want to make a straw man stand upright you run a pole right through him to give him support. Such a support is the backbone to your own body, keeping the trunk from falling together.
In the abdomen nothing more is wanted than this backbone, the sides and front of the cavity being covered in with skin and muscle only. In the chest{13} the sides are strengthened by the ribs, long thin hoops of bone which are fastened to the backbone behind and meet in front in a firm hard part, partly bone, partly cartilage, called the sternum. ”

“ Backbone is a most important article, Tommy. Professor Wyman will tell you that backbone is the distinctive characteristic of the highest order of animals on this earth. When your father used to pry into all sorts of books, years ago, he found out that he belonged to the Vertebrata, which, Anglicized, meant backboned creatures. And yet do you know that there are crowds of men and women whose framework would puzzle the good Professor, with all his learning,—people who are utterly destitute of that same essential article? ”

“ For I believe that much of a man’s character will be found betokened in his backbone. I would rather feel your spine than your skull, whoever you are. A thin joist of a spine never yet upheld a full and noble soul. I rejoice in my spine, as in the firm audacious staff of that flag which I fling half out to the world. ”

“ Things in our body, whether muscle or bone, develop by usage, and if we use the wishbone all the time it will develop into huge proportions. On the other hand if we develop our backbone and use it frequently, we may not have cause to use the wishbone so much. ”

“ On the one hand, these forms are all linked together by the fact that they have a backbone protecting a nerve-battery, and that they have never more than two pair of limbs; while every new discovery shows how closely they are all related to each other. On the other hand, they have made use of this backbone, and the skeleton it carries, in such very different ways that out of the same bones and the same general plan unlike creatures have been built up, such as we should never think of classing together if we did not study their structure. ”

“ Thus all the groups which agree in possessing a backbone and internal skeleton, although they differ widely in form, structure, and habitat, do nevertheless resemble each other more than they resemble the groups which have no backbone. ”

“ Bone for bone, the two skeletons are like one another, though man is a biped and the horse a quadruped. The backbone in man is mainly vertical; the backbone in the horse is horizontal except in the neck and the tail. Man's skull is mainly in a line with the backbone ”

“ That which is true of the limbs, is also true of all the organs; and it is on this ground that we speak of the vertebrate type. From fish to man one common plan of structure prevails; and the presence of a backbone is the index by which to recognize this plan. ”

“ But the effect on the health is far more important than that. I suppose you all know that the spine, or backbone, is intended to support the body and keep it erect. It is one of the most curious contrivances in our bodies. It is composed of twenty-four small bones, between each of which there is a piece of cartilage, or gristle, which we may compare to an India-rubber spring. The whole makes a strong column, and yet it can be bent in any direction, and is so elastic or yielding that it protects the head from jars as completely as the softest cushion could do it. ”

“ The backbone is a more deep-seated part of the skeleton than the head. It is more protected by its position, and has less varied functions to perform. Therefore it varies less in distinctive character within the limits of each of the classes of vertebrate animals than either the head or limbs. It is divided into neck bones, the cervical vertebræ; back bones, the dorsal vertebræ; loin bones, the lumbar vertebræ; the sacrum, or sacral vertebræ, which support the hind limbs; and the tail. ”

“ The Spine, Spinal or Vertebral Column, chine or backbone in man consists of a number of superimposed bones which are named vertebrae, because they can move or turn somewhat on Spine
each other. It lies in the middle of the back of the neck and trunk; has the cranium at its summit; the ribs at its sides, which in their turn support the upper limbs ; whilst the pelvis, with the lower limbs, is jointed to its lower end. ”

“ Joints.—Some bones are hinged upon each other. A bone hinge is a joint. The rings of the backbone are held together by very tough pads of flesh. Each pad lets the backbone bend only a little, but altogether they let us bend our backs in any direction. ”

“ Although the backbone can bend forward or backward, or twist from side to side a little, by the little pieces of bone of which it is built up gliding and turning upon one another, it is really very stiff and rigid, so as to protect the spinal cord and prevent its being stretched or pinched. Most of the movements which we call bending the spine are really movements of other joints which connect the {213}body or head with it. When we bend our necks, for instance, we hardly bend the backbone at all, as most of the movement is made in the joint at the top of it, between it and the skull. ”

“ The shoulders are stooped, the backbone out of plumb, the chest sunken, the hip bones protruding or twisted from a parallel, the facial muscles are wrinkled and the eyes squinted out of all normal balance. ”

“ Each of these little round flat pieces of the backbone is called a vertebra, and is of a very peculiar shape. Suppose you took a bung of bone, and fastened on to one side of its edge a ring of bone. That would represent a vertebra. The solid bung is what is called the body, and the hollow ring is what is called the arch of the vertebra. Now if you put a number of these bodies together one upon the top of the other, so that the bodies all came together and the rings all came together, you would have something very like the vertebral column (see Frontispiece, also Fig. 2) . ”

“ In producing the motions of the body, the muscles use the bones as levers. We see an illustration of the first class of levers in the movements of the head. The back or front of the head is the weight to be lifted, the backbone is the fulcrum on which the lever turns, and the muscles at the back or front of the neck exert the power by which we toss or bow the head. ”

“ The body is raised up higher from the ground, on firmer limbs; the ribs and the shoulder and pelvic bones—the saddles by which the weight of the body is adjusted between the limbs and the backbone—are strengthened and improved. ”

“ Those principles of motion may be exhibited in a skeleton, by the bending of the backbone backwards and forwards, whilst the limbs uniformly describe sections of circles in their motions, constantly moving on their axis. ”

“ And that is really what you have in the backbone. Only each vertebra is not exactly shaped like a bung and a ring; the body is very like a bung, but the arch is rough and jagged, and the bodies are joined together in a particular way. Still we have all the bodies of the vertebræ forming together a solid pillar which gives support to the trunk; and the arches forming together a tunnel or canal which is called the spinal canal, (Fig. 2, C.S.) the use of which we shall see{14}
Fig. ”

“ Physically he belongs to the great branch or phylum of vertebrate animals having a backbone—sometimes only a rod of cartilage—an internal locomotive skeleton, giving the possibility of great strength and swiftness, and of large size. ”

“ A board worn across the back to give erectness to the figure.
Thackeray.
Back¶bond· (?) , n. [Back, adv. + ÿbond.] (Scots Law) An instrument which, in conjunction with another making an absolute disposition, constitutes a trust.
Back¶bone¶, n. [2d back, n. + bone.ÿ]
1. The column of bones in the back which sustains and gives firmness to the frame; the spine; the vertebral or spinal column.
2. Anything like , or serving the purpose of, a backbone.
The lofty mountains on the north side compose the granitic axis, or backbone of the country. ”

“ In Man, in consequence partly of the disposition of the articular surfaces of the vertebræ, and largely of the elastic tension of some of the fibrous bands, or ligaments, which connect these vertebræ together, the spinal column, as a whole, has an elegant S-like curvature, being convex forwards in the neck, concave in the back, convex in the loins, or lumbar region, and concave again in the sacral region; an arrangement which gives much elasticity to the whole backbone, and diminishes the jar communicated to the spine, and through it to the head, by locomotion in the erect position. ”

“ We found in the shed an old flagstaff 15 feet long and 3 inches in diameter. The lower end of this, for about a foot, we whittled down to a diameter of 2 inches, and drove it into a hole in the backbone 12 inches from the forward end. The mast was stayed by a wire stretched from the head to an eye bolt at the fore end of the backbone. The end of the mast which projected below the backbone was stayed with wire running forward to an eye bolt and aft to a screw eye on the backbone, and also with a pair of wires running to screw eyes threaded into the crosspiece near the ends. ”

“ Frame of the Ice Boat. run from the ends of the crosspiece to the forward and rear ends of the backbone, and at the rear end several boards nailed across the braces served as a seat for the boat.
Our next task was to rig up the runners. For these we used skates, which were so arranged that we could remove them whenever we wanted to. Three blocks of wood were used for the runner shoes. Two of
Fig. 165. Runner Shoe. them were cut from a 2 by 4 scantling and measured a foot in length. The third block was only 1 inch thick, but was otherwise of the same dimensions. ”

“ I might adde to these, that Nature has made the hindmost parts of our body which we sit upon most fleshy, as providing for our Ease, and making us a natural Cushion, as well as for instruments of Motion for our Thighs and Legs. She has made the hinder part of the Head, more strong, as being otherwise unfenced against falls and other casualties. She has made Back-bone of several Vertebræ, as being more fit to bend, more tough, and less in danger of breaking, then if they were all one intire bone without those gristly Junctures. ”

“ Even the spinal cord runs down the back through a tunnel or tube, formed in a number of strong bones, so closely and firmly jointed together, that they are commonly termed "the back-bone."
Look at the eyebrows. What purpose do they fulfil? Precisely that of a shed, or arch placed over a window to shelter it from rain. But for the eyebrows the perspiration would frequently run from the brow into the eyes, and obscure the sight; a man walking in a shower of rain would scarcely be able to see; and a mariner in a storm would find a double difficulty in braving the tempest. ”

“ Bend in two this supple spine that can lift itself, like a snake erect, with something better than mere balance—with life and the active will; bend the back, and at once gravitation takes hold of the loins and grasps the knees, and pulls upon the shoulders, and the neck feels the weight of an abject head. ”

“ The back bone is intended, not only to strengthen the body, and sustain its most capacious store rooms, but also to bring down that communication of the Brain, which is usually termed the Spinal Marrow, and guards the silver cord. The Arms are exactly proportioned to each other; these being the guards which p. 69defend, and the ministers which serve the whole body, are fitted for the most extensive operations, firm with bone, yet not weighty with flesh; they bend inwards or turn outwards, they rise upwards or stoop downwards, and they throw themselves into whatever direction we please. ”

“ Why was the vertebral column at the back of the body as in quadrupeds, when it would have been more logical, in creating a man who stands on his feet, to place it in the centre of the body as a strong support, thus avoiding the curvatures and weakness of the spine that are now suffered by this disequilibrium in the support of its weight? ”

“ Advantage might occasionally be derived if the back of the hand could tell us more than it does about the shapes of the surfaces touched. Why should the thigh near the knee be twice as perceptive as the middle of the thigh? And, last of all, why should the middle of the forearm, middle of the thigh, middle of the back of the neck, and middle of the back, all stand on the lowest level, as having but one-thirtieth of the perceptive power which the tip of the forefinger has? ”

“ The most striking line in the composition is the hard long curve of the spine, which goes up without a single flicker to the back of the brutal head, as if the whole back view were built like a tower of stone. ”

“ The Human frame consists of a skeleton (fig. 73) formed of hard and unyielding bone, having joints to admit of motion in certain directions; this skeleton performs certain great and important offices, it forms strong boundaries or protecting cases for most of the vital parts, so as to shield them from external violence, such as the brain and spinal cord, the lungs, heart, &c., it also furnishes a series of levers to be acted on by the muscles, for the purposes of motion, and a firm support for the soft parts of the system. The skeleton is divided into the head, trunk, and extremities ”

“ Some of the bones, as the skull, protect delicate parts. The brain is so soft and delicate that it would be very unsafe without its solid bony covering. The spinal cord also needs the protection which it finds in the strong but flexible back-bone. The bones help to move our hands and arms, and assist us in walking.
13. The Joints.—The places where two or more bones are fastened together are called joints. Some joints we can move very freely, as those of the shoulder and the hip. Others have no motion at all, as those of the bones of the skull. ”

“ The spine consists of twenty-four short bones, each with a little ring. These vertebras are piled up one upon the other; for God has made our bodies upright; our faces, are lifted upwards, and our eyes look straight before us. These twenty-four little bones are closely and strongly bound together, and between each one and its neighbour there is something so soft and elastic that we can bend our heads, or move in any direction, without the slightest strain or jar. ”