Spinal column

“ The Spinal Cord.—The spinal cord proceeds from the base of the brain downward about eighteen inches through a canal provided for it in the vertebræ of the spinal column. It is composed of white matter on the outside, and gray matter within. ”

“ In Man, in consequence partly of the disposition of the articular surfaces of the vertebrae, and largely of the elastic tension of some of the fibrous bands, or ligaments, which connect these vertebrae 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. ”

“ The spinal column exists as a continuous notochord: the only signs of incipient segmentation being given by its membranous sheath, in the upper part of which “quadrate masses of somewhat denser [122] tissue seem faintly to represent neural spines.” Moreover, throughout sundry groups of fishes and amphibians, the segmentation remains very imperfect: only certain peripheral appendages of the vertebræ becoming defined and solidified, while in place of the bodies of the vertebræ there still continues the undivided notochord. ”

“ Reverting for a moment to the primitive segmental arrangement which is none the less persistent and important because in the completed human the regularity of contour of the segments has been wholly lost and aberrant organs have moved from their original positions carrying their nerve supply with them, let us first state and then illustrate a general law.
Any violence applied to the body tends to affect the spinal column. Such violence does or does not produce permanent displacement of a spinal segment according as it does or does not succeed in overcoming the internal resistance. ”

“ According to the Yogis, there are three principal nerve currents: one they call the Idâ, the other the Pingalâ, and the middle one the Sushumnâ, and all these are inside the spinal column. ”

“ At the same time it is fatal in another way, namely, by severing the spinal column just below its connection with the brain. The condemned man is placed upon a chair fixed on a platform, leaning his head and neck back into a sort of iron yoke or frame prepared to receive it. ”

“ It is upon the erectness, suppleness, and strength of the spinal column that most of the power and grace of the body depend. In the proper carriage the natural lines of the spinal column form a graceful and undulating line, and the body stands erect without any particular effort. ”

“ A canal is hollowed out of the column for the safe passage of the spinal cord. (See Fig. 50.) Projections (processes) at the back and on either side are abundant for the attachment of the muscles. The packing acts as a cushion to prevent any jar from reaching the brain when we jump or run, while the double curve of the spine also tends to disperse the force of a fall. Thus on every side the utmost caution is taken to guard that precious gem in its casket.
THE PERFECTION OF THE SPINE surpasses all human contrivances. ”

“ One so endowed will be found, as a rule, to exhibit a straight back, the spinal column practically vertical, viewed from the rear, and when looked at from the side, the normal curves at neck and waist line will be distinctly less marked than common. The pelvis will be nearly on a level and not markedly tilted forward and down in front, so obvious in fat people or those of lax fiber. ”

“ Slight curvature of the spine either backward or forward is helped most by exercises which tend to straighten the body, such as stretching up with the hands above the head. Lateral curvature of the spine, too often caused by a "hunched-up" position at the school desk, may also be corrected by exercises which tend to lengthen the spinal column. ”

“ The sympathetic ganglia receive nerves from the central division of the nervous system, but connect with glands, blood vessels, and the intestinal walls through fibers from their own cell-bodies. Some of these latter fibers join the spinal nerves, and some blend with each other to form small sympathetic nerves.
Protection of Brain and Spinal Cord.—On account of their delicate structure, the brain and spinal cord require the most complete protection. In the first place, they are surrounded by the bones of the head and spinal column ”

“ Once formed, a palpation habit, right or wrong, is very hard to break. Many a teacher has expended himself uselessly in the effort to undo some technical fault acquired by the student in a blundering undirected trial.
Facts Concerning the Spine
The spinal column is composed of twenty-six segments called vertebrae, twenty-four movable and two fixed. The movable vertebrae are divided for convenience in study into three sections. There are seven Cervical vertebrae, twelve Dorsal, and five Lumbar in the normal individual. ”

“ The typical course of a spinal nerve is around the body to the ventral surface, giving off branches to the muscles and skin of its segment. A short distance from the vertebral column the spinal nerves lie just outside the peritoneum, through which many of them can be seen and followed to about the level of the lateral vein. At this point they pass outward into the muscles of the body wall. To dissect any of the spinal nerves make a longitudinal incision along the lateral line and separate the dorsal muscle mass from the lateral muscles for some distance. ”

“ 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. ”

“ The habitual rigidity of the spine, as compared with its possible freedom, is more noticeable in training, of course, than is that of any other part of the body. Each vertebra should be so distinctly independent of every other, as to make the spine as smoothly jointed as the toy snakes, which, when we hold the tip of the tail in our fingers, curve in all directions. Most of us have spinal columns that more or less resemble ramrods. It is a surprise and delight to find what can be accomplished, when the muscles of the spine and back are free and under control. ”

“ In most cases of spinal deviation it will be found that the column yields on the right side, and the cause of this may be traced to a very early period. In infancy the child is taught to use the right hand in preference to the left ”

“ SPINAL CORD, in anatomy, that part of the central nervous system in man which lies in the spinal canal formed by the vertebrae, and reaches from the foramen magnum to the lower margin of the first lumbar vertebra. It is about 18 in. long, and only occupies the upper two-thirds of the spinal canal. The cord is protected by the same three membranes which surround the brain. Outside is the dura mater, which differs from that of the brain in not forming a periosteum not to the bones, in sending no processes inward, and in having no blood sinuses enclosed within its walls. ”

“ The spine is a very important structure indeed. It houses the spinal cord, without which one is paralysed, without which one is useless as a human. But the spine is more important than that. Right in the centre of the spinal nerve, the spinal cord is a tube, which extends to another dimension. It is a tube upon which the force known as the Kundalini can travel when awakened. ”

“ As near as I can make out, the effusion of blood within the spinal canal has been safely absorbed, or nearly so. There seems to be no displacement or injury to the spinal bones; there is no wasting away of the muscles as would be the case if the spinal cord were injured. There is, I believe, good reason to hope that the loss of power in his legs is a sequel of organic conditions which have now passed away. ”

“ From these facts it will be readily understood that a lesion occurring in any portion of one lateral half of the spinal cord of man must be followed by some or all of the above-mentioned symptoms, and that the phenomena produced by physiological experiments on animals constitute, in reality, the pathological basis of unilateral spinal paralysis in man. They will be more clearly understood by calling to mind the course of the musculo-motor, vaso-motor, and sensitive tracts in the spinal cord. ”

“ In many cases, as has been remarked before, the pathological process descends into the spinal cord. Here, as in the medulla oblongata, the degeneration is principally confined to the motor centres located in the anterior horns, while the posterior horns, together with the lateral and posterior white columns, remain free from disease. The degree of degeneration taking place in the fibres of the respectively paralyzed muscles also corresponds to that of the elements of the nerve-centres from which they are supplied. ”

“ The spinal cord, as we have seen, is a mass of nervous substance continuous with the brain; from the spinal cord nearly all the nerves of the body are given off; those nerves whose branches go to the biceps muscle in the arm leave the spinal cord somewhere in the neck. ”

“ When the spinal cord has been severed in the neck this scratching movement of the hind limb can be elicited with regularity as a spinal reflex by merely rubbing the skin of the side of the neck or shoulder, applying there a weak electric current to the skin. In this reflex the stimulus excites afferent nerves connected with the hairs in the skin and these convey impulses to the spinal centres in the neck or shoulder segments, and these in turn discharge impulses into nerve fibres entirely intraspinal passing backward along the cord to reach motor centres in the hind limb region. ”

“ The tissue of the neural arches does not any longer form a continuous sheet, but is divided into (1) a series of arches encircling the spinal cord, and (2) a basal portion resting on the cartilaginous sheath of the notochord. There are two arches to each muscle-plate, one continuous with the basal portion of the arch-tissue and forming the true arch, which springs opposite the centre of a vertebral body, and the second not so continuous, which forms what is usually known as the intercalated piece. Between every pair of true arches the two roots of a single spinal nerve pass out. ”

“ To all intents and purposes the same thing is seen in the termination of the spinal cord in a bird-embryo; more and more, as the end of the tail is approached, does the nervous matter of the spinal cord grow less and less, until at last a naked central canal with its lining epithelium is alone left to represent the so-called nerve-tube. ”

“ A spinal tube is formed in the external skin of the back, and from this first comes a simple spinal cord without brain, such as we find to be the permanent psychic organ in the lowest type of vertebrate, the amphioxus. ”

“ When there is a small sub-luxation of many vertebræ together, the distortion occasions a circular flexure of the spine, and in this case some are apt to be deceived, and take it for a complete dislocation of one spine, whereas a complete dislocation of one spinal vertebra does not produce a circular but an angular flexure of the spine, which is attended with more danger. ”