. The eclectic guide to health; or, Physiology and hygiene ... ongatapasses out to the stomach and lungs. Thisnerve controls the process of breathing. Theleast injury to the medulla oblongata at theorigin of this nerve causes instant 119. The spinal cord is a continuationof the medulla oblongata into the openingprovided for it in the spinal column. It isprotected by the vertebrae and a continuationof the membranes that cover the brain. Itis about fifteen inches long, and as largearound at the upper end as the little substance of the cord is chiefly whitematter, with some gra
. The eclectic guide to health; or, Physiology and hygiene ... ongatapasses out to the stomach and lungs. Thisnerve controls the process of breathing. Theleast injury to the medulla oblongata at theorigin of this nerve causes instant 119. The spinal cord is a continuationof the medulla oblongata into the openingprovided for it in the spinal column. It isprotected by the vertebrae and a continuationof the membranes that cover the brain. Itis about fifteen inches long, and as largearound at the upper end as the little substance of the cord is chiefly whitematter, with some gray matter extendingthrough the middle portion. Deep fissures,extending lengthwise of the cord, separate itinto right and left halves. The cord connectsthe brain and the nerves of the body. InFig. 52, we see a front view of the right sideof the spinal cord, showing the origin of thespinal nerves; 1 is a portion of the medullaoblongata, 2 is the anterior fissure, 3 is the root of theeighteenth spinal nerve of the right side. Fig. 52. Spinal Coed. n6 Fig. 53- 120. Spinal Nerves.—From the sides of the spinalcord, as a trunk, there originate thirty-one pairs of nerves,called spinal nerves. See Fig. 52. These nerves originateupon opposite sides of the cord, in nearly regular intervalsalong its entire course, and pass out through openingsbetween the vertebrae at the sides of the column. Eachnerve springs from the cord by two sets of fibers, called itsroots, one set of which comes off from the front portion,and the other from the rear of the side of the cord. Thesetwo sets of fibers soon unite to formone nerve, which leads away to certainparts of the body. The fibers that comeoff from the rear of the cord are dis-tributed to the skin. These are thefibers by which we feel, hence they arecalled sensory fibers. The fibers thatarise from the front portion of the cordlead to the muscles. These are the fibersby which we move the muscles, hencethey are known as motor fibers. The
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