Cord

“ The Reflex Action of the Cord.—We have already considered the cord as the great motor and sensory nerve of the body, but it has another and extremely important use. By virtue of the gray matter, which occupies its central portion, it plays the part of an independent nerve centre. The spinal cord not only conducts some impressions to the brain, but it also arrests others ”

“ In desperate excitement I began to work the cord between my wrists up and up between my palms until I could just reach it with my little finger, and by a supreme effort slipped it over my left hand. Great God, I was free! I could now move my hands, although they were still tightly tied together round the wrists. In frantic despair I began to tug and tear at the cords which bound them. ”

“ When the posterior root enters the gray substance of the cord, there is no more necessity for its fibres passing directly into the cells of that gray substance, in order to excite their activity, than there is for a wire to pass from the bell to the ear of the servant, who hears the vibrations of the bell through the pulsations of the intervening air upon her tympanum. ”

“ Cord, kord, n. a small rope or thick kind of string: something resembling a cord, as 'spinal cord,' 'umbilical cord,' &c.: (fig.) anything that binds or restrains: a measure of firewood, originally determined by the use of a cord or string.—v.t. to supply with a cord: to bind with a cord.—n. Cord′age, a quantity of cords or ropes, as the rigging of a ship, &c.—adj. Cord′ed, fastened with cords: furrowed, as with cords: (her.) wound about with cords: piled in 'cords.'—ns. Cord′-grass, a genus of grasses of which one species found in muddy salt-marshes is used for making ropes ”

“ 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. ”

“ Ventral Cords.—The histology of the ventral cords and œsophageal commissures is very simple and uniform. They consist of a cord almost wholly formed of nerve-fibres, placed dorsally, and a ventral layer of ganglion cells (figs. 16 and 20) .
The fibrous portion of the cord has the usual structure, being formed mainly of longitudinal fibres, each probably being a bundle of fibres of various sizes, enveloped in a sponge-work of connective tissue. The larger bundles of fibres are placed near the inner borders of the cords. ”

“ If a strong thread or small cord be tied tightly round the finger of a living person, the portion beyond the cord or thread will become red and swollen—if dead, no change is produced. 3. If the hand of a living person is held before a strong light a portion of the margin or edges of the fingers is translucent—if dead, every part of it is opaque. ”

“ Unloose the cord, and they will wrap you round. ”

“ The spinal cord serves as a conductor of sensation and of motor impulses, and it also plays the part of a brain for those structures of the body which lie below the head. It gives off nerves like streamlets. ”

“ In order better to explain these endless cords, fig. 574. represents a single endless cord 1, 1, which is here shown in operation, and part of another endless cord 2, 2, shown stationary. There must be as many endless cords in this frame as needles in the weaving-loom. a is the wooden cylinder, revolving upon its axis at the lower part of the standards; b b, the two pulleys of the pulley-frames above, over which the individual endless cord passes; c is a small traverse ring. To each of these rings a weight is suspended by a single thread, for the purpose of giving tension to the endless cord. ”

“ The process of spinning cord or thread is always the same. In its most primitive form it consists simply in rolling between the palms of both hands, or with one hand on the thigh, the fibres of some textile substance. This is how the Australian proceeds to make a line with his wife’s hair, or the New Zealander when he transforms a handful of native flax, inch by inch, into a perfect cord. ”

“ Every one considers it as a medullary cord, extending from the head to the sacrum, sending in its course various ramifications to the neck, the thorax and the abdomen, following in its distributions a course analogous to those nerves of the spine, and deriving its origin from those nerves, according to some, and from those of the brain, according to others. ”

“ Fibers from these cells extend down through the brain and cord to the muscles, the fibers being collected into well-recognized bundles and the whole known as the motor tract. There may be one long fiber from a cell in the brain down through most of the cord or there may be a succession of shorter fibers that are not actually connected but are in close contact with each other. ”

“ The general idea of the relations of the brain and spinal cord is that the brain commands and the cord obeys. The brain requires such or such a movement, and the cord, working unconsciously, coördinates the elementary and individual movements required to produce the desired effect. ”

“ Cord to be well stretched.--It is an imperfect security to tie an ingenious active man, whose hands and feet are small, unless the cord or whatever else you may use, had been thoroughly well stretched. Many people have exhibited themselves for money, who allowed themselves to be tied hand and foot and then to be put into a sack, whence they emerged after a few minutes, with the cords in a neat coil in their hands. ”

“ On turning the wheel, and properly regulating both the tension and the rapidity of rotation, the beaded cord may be caused to rotate as a whole, and to divide itself successively into 2, 3, 4, or 5 ventral segments. When we envelop the cord in a luminous beam, every spot of light on every bead describes a brilliant circle, and a very beautiful experiment is the result. ”

“ The cords are wound in opposite directions on their pulleys, so that the unwinding of the cord from the larger pulley, and the rotation of the same, winds up the cord on the smaller pulley, and causes the bird to move forward on what seems to be only a single length of cord, the backward movement taking place by gravity when the pull on the string is released. ”

“ If the spinal cord is divided in the middle of the back, for example, the skin of the feet may be cut, or pinched, or burned, or wetted with vitriol, without any sensation of touch, or of pain, arising in consciousness. ”

“ Further, it was found that in all vertebrates the great central mass of the nervous system, known as the brain and spinal cord, is in reality a hollow tube with more or less thickened walls, developed as a strand of tissue along the dorsal surface of the embryo, which sinks downwards and inwards to form a hollow tube lying dorsal to the notochord. ”

“ If a cord of but moderate thickness be fastened at each end to a thin piece of wood, say a split shingle, and a little block of wood, in imitation of the bridge of a violin, be placed under the cord so as to render it tense, we have the essentials of a stringed instrument, the pitch of which can be made to vary by moving the block about and thus varying the tightness of the cord. ”

“ A cord fixed behind the scapula of the opposite side by a ring which passes over the clavicle and under the axilla, extends down the posterior surface of the arm and forearm pieces, running in pulleys which keep [100] it in place. If the patient bends the elbow and at the same time brings the arm and both shoulders forward, rounding his back, the cord is tightened and pulls the thumb into the position of abduction and extension. ”

“ In relation to the brain, the spinal cord is a great mixed motor and sensory nerve, but, in addition to this, it is also a distinct nervous centre, in which originate and terminate all those involuntary impulses which exert so potent an influence in the preservation and economy of the body. ”

“ Meanwhile we may remark that the arrangement of cells and fibres which is imagined as the mechanism of propagation and reflexion is absolutely irreconcilable with the teaching of Experiment: for the spinal cord may be cut through anywhere, without destruction of the transmission of sensory and motor excitations, provided only a small portion of gray substance be left to establish the continuity of the axis. ”

“ A threefold cord is much fuller and firmer than a twofold one. Cords can be made of wool or silk or any kind of thread, and must be made of few or many strands according to the thickness required, and according to the thickness of the strands used. Thin woollen cords are very nice to run into woolen garments as drawstrings, or into bags; thick ones made of knitting yarn are splendid for dressing-gowns, and the ends can be finished off with tassels. ”

“ From one hundred to several thousands of neck and simple cords could be used in one harness. The design to be reproduced in cloth was read into the parallel lines of the simple by looping a piece of string round each cord that governed warp threads to be lifted for a given shed; after which all the loops were bunched together. ”

“ When we come to consider that the spinal cord, or marrow, runs down through the long, bony shaft made by the vertebrae, and that the brain and spine, though connected, are bound up in one continuous bony wall and covered with this inflamed membrane, it is not difficult to understand that the thing is very hard to get at. ”

“ Fig. 20.—a, axis cylinder formed by the fibrils of the cell contents, and at a’ assuming the medullary sheath; b, naked axis cylinder from spinal cord.
A nerve is a bundle of fibres within a membranous envelope supplied with blood-vessels. Each fibre has also its separate sheath, having annular constrictions at various intervals. It is more correctly named by many French anatomists a nerve-tube rather than a nerve-fibre ”

“ It is a long mass of nerve tissue, branching off at the several vertebrae to nerves communicating with all parts of the body. The Spinal Cord is like a large telephone cable, and the emerging nerves are like the private wires connecting therewith. ”

“ The motionless extremities are called nodes, and the middle is a belly. We can also draw the bow across this cord in such a manner that, while vibrating as a whole, the two halves of the cord will each vibrate on its own account, following a law of individual vibration. ”

“ I suppose we knit and gossip with the spinal cord; indeed we may sing and pray, not with our hearts, nor with our brains, but with the upper part of our spinal cords. We tip our hats to each other, not with our brains, but mainly with our spinal cords ”

“ One can easily see the marks of where the cords have worn slight grooves or abrasions between the different perforations. This is where it differs from all the tablets with two perforations only that have come under my observation, as they as a rule never bear any marks of cords. [4]
This tablet, it will be noticed, bears on its upper margin a slight notch or groove, worn smooth as by the wearing of a cord. ”

“ If we follow a ganglionic fiber into the spinal cord or brain, we find that it forms two branches, as first recorded by Ramon y Cajal, a distinguished Spanish histologist; of these two branches, one runs upward, or in the brain forward, and the other runs downward, or in the brain backward ”

“ The substance bounding the groove on each side next rises up into a fold, the rudiment of the side wall of that long cavity, which will eventually lodge the spinal marrow and the brain; and in the floor of this chamber appears a solid cellular cord, the so-called “notochord.” One end of the inclosed cavity dilates to form the head (Fig. 13, B) , the other remains narrow, and eventually becomes the tail; the side walls of the body are fashioned out of the downward continuation of the walls of the groove ”