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    6 THE NERVOUS SYSTEM

    Nerves.-Two nervous systems in living animal bodies: organic, and nerves of animal life.-Structure of nerves, and the size of component parts of nerves.-Center of organic nervous system.-The solar plexus.-Ganglia.-Suspension of the action of organic and animal nerves: the effect.-Distribution of animal nerves.-Nourishment of nerves.-Illustration of sympathetic, or organic nerves.-Important relation of the stomach to the nervous system.-The cerebro-spinal, or animal nervous system.-Its center, the brain.-Structure of the brain: its size, divisions, and coverings.-Cerebrum.-Cerebellum.-Cerebro-spinal nerves: their origin.-Spinal marrow.-Medulla oblongata.-Cranial nerves.-Arbor vitae.-Ganglia of the brain.-Nine pairs of nerves.-Thirty-one pairs of spinal nerves.-Action of the brain.-Injuries of the brain: the effect.-Inactive in profound sleep.-Sleep: proper amount; how taken; in what rooms; best time for sleep, etc.-Exercise of the brain: result.-Phrenological arrangement of the brain.-The mind of man.-Faculties, and propensities.-True happiness.-Effect of mind on body, and of the body on the mind.-Pneumo-gastric, or lung-and-stomach nerve.-Its importance.-Effects of the mind on the stomach, and of the stomach on the mind.-Disease of the nervous system

    Figure XII
    PICTURE
    NERVOUS SYSTEM

    225. What is the nervous system?HBH 88.1

    It is, in many respects, the most important and interesting portion of the human body. It is the highest order of organized matter, is the immediate organism of vitality, and the vital operations, and the intellectual manifestations; and hence it has been said, that the nervous system constitutes the man; and that the bones and muscles, and the whole assemblage of internal organs, with their various functions, are only intended to sustain and serve the nervous system. All impressions on the mind from the external world, and all mandates from the will to the muscles, are conveyed through the medium of the nervous substance. All motions, changes, or functional actions which are performed by the muscles of the body, depend on the power, energy, or influence transmitted to the muscular tissue from the nerves.HBH 88.2

    226. Is vitality peculiar to the nervous system alone?HBH 89.1

    The nerves are more highly endowed with vital properties and powers, than any other substance of the body; and they are, in the animal kingdom, the immediate instruments of vitality in all the wonderful operations of the body. Vitality in various degrees, however, pervades all the tissues of the living body. The blood seems to be a living fluid, as also the chyle, especially in its more advanced stages of assimilation. Through the action of the nerves on the appropriate organs the food is digested into chyme, and thence into chyle, and thence into blood. The blood is transformed into the various solids and fluids of the system, and, at the same time, by the nerves, it is supposed that the temperature of the body is regulated. By virtue of the vital endowments of the nerves, we perceive our internal wants, and external conditions, and relations, and by these nerves we act upon the muscles, and through them upon the bones in our voluntary motions. By the mysterious endowments of the nervous substances, we think, and reason, and feel, and act, as intellectual and moral beings.HBH 89.2

    227. Do the functions of all organized bodies depend on a system of nerves?HBH 89.3

    There are, in all organized bodies, both animal and vegetable, a class of functions which are concerned in the nourishment, growth, temperature, and general sustenance of the body as an organized being. There is a tissue in vegetable bodies, which, in its functional character, corresponds with the nervous tissue of animals, as nearly as the functions of vegetables and animals correspond in their processes and results. The vegetable seed, by virtue of its own vitality, excited to action by a genial soil and other appropriate circumstances, puts forth its little roots into the earth, and absorbs foreign matter, and converts it into the substances and texture of its own organism. So far as those vital operations are considered by which chyme, and chyle, and blood are produced, and the blood circulated through the system, and the body in all its parts nourished, and its growth and development effected, and all the other functions of organic life sustained, the animal differs but little from a vegetable; and in health, is equally destitute of animal consciousness. In animals, however, there must be care used in the proper selection of substances to nourish the body, instead, like the plant, of its getting all its nutrition on a fixed spot. So, in animals, there are organs of sensation, locomotion, and prehension, subject to voluntary control. The primary office of these organs is to perceive and procure the materials by which the body is nourished, and place them within reach of those organs of nutrition. The Zoophytes, the lowest order of animals, have furnished a matter of controversy with naturalists, as to whether they were animal or vegetable. They are but dimly conscious of their being, and are nourished by means which hardly demand faculties superior to those with which the vegetable is nourished.HBH 89.4

    228. Into how many systems may the nervous system be divided?HBH 91.1

    Into two: the organic, comprising those nerves concerned in, and presiding over, the functions of digestion, absorption, respiration, circulation, secretion, organization, or the process of structure, and the production of animal heat. The other system is called the cerebro-spinal, comprising the nerves of sensation and motion. To this latter belong consciousness, the perception of external impressions and internal affections, reflection, volition, and other faculties called intellectual. The first of these systems is composed of all those nerves called sympathetic, which preside over the functions of organic life. The second comprises the brain, spinal marrow, and nerves of sensation and motion. This might also be divided into other systems called the motory, or nerves of voluntary motion; the sentient, or nerves of sensation: and the mental, or the brain.HBH 91.2

    229. What is the structure of the nerves?HBH 91.3

    The nervous substance is sometimes white, sometimes gray, and in the organic system of a reddish color. This tissue of the nerve fiber is enclosed in membranes or sheaths. The ultimate nerve fiber is tubular, consisting of an external, thin and delicate membrane, which forms a sheath, within which is contained a more opaque substance, called the white substance of Schwam; and within this white substance is a transparent material which may be made to move in the cavity of the tube.HBH 91.4

    230. What is the comparative size of the component parts of a nerve?HBH 91.5

    The nerve fibers vary in size from one two-thousandth to one fourteen-thousandth of an inch in diameter. A nerve is made up of a bundle of these fibers, enclosed in a sheath.HBH 91.6

    231. What is the grand center of the nervous energy of the body?HBH 92.1

    The nervous system has been by many reckoned as the brain and spinal marrow, with numerous cords, branches and twigs, dispersed over the whole organized system. Those holding this theory claim the brain as the grand center of the nervous system, or a kind of galvanic battery which continually generates nervous energy and presides over all the vital functions of the system. The brain is undoubtedly the central point of sensorial power, but it does not seem to be the presiding center of those nerves by which the development of the different parts of the body is effected. If the brain were the presiding center of vital operations in the formation of the body, then all the branches belonging to this center would issue from it, and go out with the blood-vessels, to preside over their functions, in the formation of other parts, and enter into the texture of parts thus constructed; but, instead of this, the branches of the spinal nerve are mostly distributed to the voluntary muscles, and to the outer surface of the body. Again, children have been born with all parts of the body well developed, except the brain and spinal marrow, and it is a fact that the brain and spinal marrow are among the last parts of the body brought to that consistency which enables them to exercise a functional power. Although, as we shall show, the condition of the cerebro-spinal system of nerves may and does greatly affect the healthful action of the organic nerves, yet we conclude that the grand center of nervous vital energy is the central point of the nerves of organic life.HBH 92.2

    232. What is the central point of the nerves of organic life?HBH 93.1

    In the midst of those parts of the body first produced, in its natural order of development, we find a mass of nervous matter, which, in composition, very nearly resembles the brain. This is undoubtedly the first-formed portion of the human body, and is the grand center which presides over all the functions concerned in the growth of the body and the functions of nutrition during life. This central mass of nerve is situated at the roots of the diaphragm, in the upper and back parts of the abdominal cavity, or nearly back of the pit of the stomach, and consists of several parts; two semi-circular bodies about an inch long and half an inch broad, lying, one on the right, and the other on the left side of the back bone. These are called the SEMILUNAR GANGLIA. They are, probably at first one, and afterward partially separate to accommodate themselves to the duplicate arrangements of the body. They are, however, closely connected by many large branches, which pass from one to the other, and form what is called the SOLAR PLEXUS.HBH 93.2

    233. What do we find connected with the solar plexus?HBH 93.3

    Numerous branches of nerves go out from this central brain, in different directions. They are threads of a reddish color, and have connected with them oval bodies called ganglia, which are never so large as peas. These ganglia and nerves extend along each side of the spinal column from the atlas to the coccyx, and distribute branches to all the internal organs and viscera, and communicate with all the nerves of the body. The branches which are given off to the internal organs accompany the arteries to the same.HBH 93.4

    234. What other arrangement is connected with these nerves?HBH 94.1

    The ganglia above mentioned serve as smaller and subordinate brains, which become the more special centers of development, and of perception and action, to individual organs, or particular apparatuses of organs; and these special centers, in their turn give off numerous branches, some of which enter into the texture of the blood-vessels formed for, and appropriated to, their service in the construction of their particular organs; others are distributed to the contractile tissue or muscles of those organs to convey the stimulus of involuntary motion; others are the conductors of impressions made upon the organs, to their special centers. To establish an intimate connection between the different special centers, and bring them all into direct relation to each other, and to the common center, large cords run directly from one center to another; and numerous branches go from each center, to interlace and unite and form plexuses, 1Plexus is a Greek word signifying to weave. The plexus is a net-work of nerves. with branches coming from several other special centers, and from the great common center. Some of these plexuses are formed around the internal organs and are named after the arteries extending to those organs; as the mesenteric, hepatic, splenic, etc. To the naked eye the plexus looks as though the nerve was lost, but by the microscope each fiber can be traced distinctly through the plexus.HBH 94.2

    235. What can you say of the order and development of these organic nerves, and their presiding centers?HBH 95.1

    As the alimentary canal and the other organs associated with it in the general function of nutrition are developed before any other part of the body, their special centers and nerves are the first produced. At an early stage in the development of the body numerous fibers rise on each side of the general mass, which form a pair of large cords, called the trisplanchnic nerves, which give rise to an uninterrupted series of small brains, which gradually separate in a longitudinal direction, and draw farther and farther apart, keeping up their connection with each other by intermediate branches, till they form a connected range of about fifteen little brains, on each side of the spinal column, from the diaphragm to the top of the neck. The trisplanchnic nerves are divided in their upper portions into from three to seven or more branches, which terminate in as many of the little brains in the two ranges. Eight or nine more of these little brains are arranged in a similar manner from the diaphragm downward. So, in the completely-developed body, there is a continued series of these brains, or special centers, on each side of the backbone, from the base of the cranium to the inferior extremity of the spinal column. Each of these little brains sends out numerous branches, which serve to unite the little centers to each other; others plunge into the muscles; and others form connections with the nerves and muscles of animal life. Other branches go to interlace and form numerous plexuses with branches of others from the same, and of the opposite side, and from those more deeply seated among the viscera, and from the great central mass itself. From these plexuses, again, numerous branches are given off to the different organs, entering intimately into their texture. And all the branches and twigs of this system of nerves, as they proceed along their course to their destination, cross, and unite, and divide, and interlace, so as to form of the whole system one extended net, the meshes of which become smaller and smaller, as the nerves approach their inconceivable-minute termination in the organs. These two series of little brains, with their connecting cords, etc., bring all the organs with which they are connected into a very close union, and establish between them a most powerful bond of sympathy. By the aid of the numerous branches which pass from the several plexuses to different organs, the whole assemblage of organs concerned in the functions of organic life, is, as it were, woven into one grand web of nervous tissue.HBH 95.2

    236. What further can you say of this system of nerves?HBH 96.1

    They preside over all the vital functions in the development and sustenance of the body, while the other special centers are more immediately concerned in the development of the organs employed in the general function of nutrition. It is probably the truth in the matter that the two series of brains or special centers which extend the whole length of the spinal column, are more immediately concerned in the development of the spinal nerves, and of the cerebro-spinal system generally, and of the other parts pertaining to the trunk and extremities.HBH 96.2

    237. How many orders of ganglia of organic life are there?HBH 96.3

    There are two: called the central, and the peripheral or limiting ganglia. The central are those connected with the internal organs, and are supposed to preside, generally and specially, over the functions concerned in nourishing and sustaining the body. The limiting are those which form the two ranges on the sides of the spinal column, and have been supposed to be more particularly appropriated to the general sympathies of the internal system, and are accordingly called the sympathetic nerves. This general system of nerves is called the ganglionic system. They are most commonly called THE NERVES OF ORGANIC LIFE, in contra-distinction to the brain and spinal marrow, with their branches, etc., which are called THE NERVES OF ANIMAL LIFE.HBH 97.1

    238. What is the effect produced by suspending the action of the organic nerves?HBH 97.2

    A single moment’s entire suspension of the functions of the nerves of organic life, would be a death from which there would be no resuscitation. The functions of the nerves of the cerebro-spinal system may be suspended for a considerable time, and still the common vitality of the body be preserved. Andrew Wallace, a revolutionary veteran who lived to the age of 105 years, was struck down by lightning while tending a cannon on the fourth of July, soon after the close of the American Revolution, and lay seventeen days in a state of suspended consciousness. He revived after it, and was remarkably vigorous and active.HBH 97.3

    239. How many orders are there to the nerves of organic life?HBH 97.4

    Three: the first, those nerves that enter into the texture of blood-vessels, and go with them to their most minute terminations in the different tissues, and preside over all their functions of absorption, circulation, secretion, structure, etc.; the second, those nerves that go to the contractile tissue, or muscles of involuntary motion in the texture of the organs, and convey to them the stimulus of motion; the third, those which convey to the special centers, and, if necessary, to the common centers, the impressions made upon organs. The cords which serve to connect the special centers to the common center, and to each other, are probably composed of filaments of all these three orders.HBH 97.5

    240. What is observable in the distribution of the nerves of organic life?HBH 98.1

    The heart seems to require and possess but few of these nerves. This is likewise true of the large blood-vessels. But in the capillary system, or minute extremities of the vessels, where all the important changes take place, the nerves much more largely abound. Of all the organs of the body, the stomach is the most remarkable for its nervous endowment, and sympathetic relations. Lying near the great ganglionic center, it receives a large supply of nerves directly from that source, and is thereby brought into the closest sympathetic union with the common center of organic life, and through it, with all the organs and parts in its domain. By the arrangement and distribution of plexuses, also, the stomach is brought into very direct relations with the heart, liver, lungs, and all the other organs.HBH 98.2

    241. From whence do the organic nerves derive their nourishment and support?HBH 98.3

    They evidently derive their support, as well as the elements by which they operate to control and regulate the organic functions, in a great measure directly from the arteries, for which purpose also, some of their structural parts penetrate the arterial coats?HBH 98.4

    242. Is the mind conscious of the operations of the organic nerves?HBH 99.1

    In a healthy condition of the bodily organs these nerves have no sensibility of which the brain takes cognizance. For instance, the brain does not feel food in the stomach, nor blood in the heart, nor air in the lungs, nor bile in the liver, yet their pressure is recognized or felt by the organic nerves. When, therefore, we are conscious that we have a stomach or a liver, from any feeling in those organs, we may be certain that something is wrong. These nerves are endowed with an exquisite organic sensibility, which qualifies them most perfectly for the performance of their constitutional functions in the living system; and the complete integrity of those functions essentially depends on the healthy properties of the nerves. But the organic sensibility of these nerves may, by continued or repeated irritation, become exceedingly diseased, and a diseased sympathy may be induced and permanently established. In this state of things, all the functions of organic life are necessarily impaired. The food is less perfectly digested in the stomach, the chyle is less perfectly elaborated, the blood necessarily becomes deteriorated, and the whole system, in every part and tissue consequently suffers. By continued irritation, inflammation may be induced, and the most painful sensibility developed in these organs. This state of things is not only distressing, but is always injurious, and often hazardous to life.HBH 99.2

    PICTURE

    Figure XIII
    PICTURE
    GANGLIONIC SYSTEM

    243. What is Fig. XIII designed to illustrate?HBH 101.1

    The ganglionic or organic nervous system. As may be seen by the little lines running in every direction, and to every organ of the body, it forms a complete system of telegraphic communication with every part of the body. A A A, is the semilunar ganglion and solar plexus, the great presiding center or brain of the organic nervous system. Various sensations usually referred to the heart, have, no doubt, their source in this ganglion. B, and C, C, greater and lesser trisplanchnic nerves. These nerves connect with the nerves of the base of the cranium, with the ganglia of the vertebral column before described, with the solar plexus, and with the renal plexus, which extends from the solar plexus to the kidneys. D D D, are the thoracic ganglia, which consist of twelve ganglia on each side, resting upon the head of the ribs. E, their internal branches which follow the pulmonary artery, to the plexus of the throat, heart, and splanchnic nerve. Several nervous cords from the lower ganglia, as will be seen in the figure, unite to form the splanchnic nerve. F, internal branches of the thoracic ganglia, which extend to the roots of the spinal nerves. G, right coronary plexus, which is placed around the right coronary artery of the heart. H, left coronary plexus, around the left coronary artery of the heart. These are both connected by branches with the principal nerves of the ganglionic system. I, J, K, L, M, N, O, P, Q, R, S, T, superior, middle, and inferior, cervical glands, with their branches. They extend from the base of the skull to the third cervical vertebra, and send branches to the organs of the throat, upper part of the chest, especially to the heart.HBH 101.2

    U, submaxillary ganglia, which are connected with the glands of the lower jaw and several of the facial nerves. W, naso-palatine branch of the vidian nerve, extending to the nose and palate. X, spheno-palatine branches of the vidian nerve. These are four or five nerves, extending to the mucous membrane, spongy bones of the nose, and to the pharynx. Z, auditory nerve, extending to the ear. 1, renal plexus, extending from the solar plexus to the kidneys. 2, 3, 4, lumbar ganglia with its branches, which consist of four ganglia on the front part of the lumbar vertebra, which are distributed to all the viscera of the lower organs of the body. 5, the aortic plexus, which is a combination of the lumbar ganglia around the aortic artery in the abdomen.HBH 102.1

    244. In a close view of the nerves of organic life, as illustrated in the above figure, which organ seems to be placed in a position to have the most sympathetic influence on the others?HBH 102.2

    The degree of sympathetic influence which each organ has on the others, is always proportionate to the functional importance of the organ in the system, and the nearness of its nervous relation to the great center of organic life. The stomach holds an immensely-important station in the assemblage of vital organs. It is supplied largely with nerves from the great center of organic life, and associated by plexuses with all the surrounding organs, and hence it sympathizes more directly and powerfully with every other internal organ, and with every part of the living body, than any other organ; and, in turn, every other internal organ, and every part of the living body, sympathizes more directly and powerfully with the stomach than with any other organ. If proper and healthful food be placed in the stomach, it is healthfully excited, and all the other organs rejoice with it and take hold with alacrity to perform their labor; but if an improper substance irritates the stomach, all the other organs mourn with it, and their functions are disturbed by it. By carefully considering this bond of sympathy in the entire domain of organic life, we shall certainly realize the force of St. Paul’s expression, when, using the human body as an illustration, he says: “And whether one member suffer, all the members suffer with it, or one member be honored, all the members rejoice with it.” 11 Corinthians 12:26.HBH 102.3

    245. If there is no sensibility of which the mind takes cognizance in the action of the organs of the vital domain, how do we know when we are diseased, or when we want food or drink?HBH 103.1

    It was the healthy action of which we said the mind had no knowledge. We have just stated that unhealthy and irritating action produces the most distressing agony. This the mind is cognizant of, not because of the nerves of organic life, but because of another class of nerves which are established for the express purpose of imparting to the mind a knowledge of the wants and ills of the human system. This system of nerves, with the intimate connection between the two systems, and their effect upon one another for good or ill, will now occupy our attention. This second system of nerves, as we have already told you, is calledHBH 103.2

    THE CEREBRO-SPINAL NERVOUS SYSTEM.HBH 103.3

    246. What is the grand center of the cerebro-spinal nervous system?HBH 103.4

    The brain.HBH 104.1

    247. Where is the brain situated?HBH 104.2

    The brain is in the head, occupying the whole inner part or cavity of the skull, but separated from it by a thin membrane.HBH 104.3

    248. Of what is the brain composed?HBH 104.4

    Of the same substance as the nerves. It resembles marrow, and is filled with blood-vessels, the whole brain having a grayish color.HBH 104.5

    249. How large is the brain in a grown person?HBH 104.6

    It is about six inches long, five inches wide, and four inches thick. It weighs from three to four pounds, and will fill the two hands of a man. The brain of man is larger than that of any of the lower animals except the elephant and whale. The elephant’s brain weighs about eight pounds, the whale’s brain about five pounds.HBH 104.7

    250. Has a person more than one brain?HBH 104.8

    Yes; there are two brains. The larger one is called the cerebrum, and another, about one-half as large, below and behind it, is called the cerebellum. These two brains are equally divided into two parts by a deep cut or separation, reaching nearly through them from front to back. These halves of each brain are precisely alike in shape, and together form a pair of brains, just as we have a pair of eyes and ears. We see the wisdom of the Creator in thus arranging the brain organs in pairs. One side of the brain may be injured, and the other will perform the functions of those organs. Or one side may be paralyzed, and yet the life of the person is not destroyed, but still the brain and nerves act.HBH 104.9

    PICTURE AND TEXT
    Figure XIV
    PICTURE

    251. What does Fig. XIV represent?HBH 105.1

    It represents the brain exposed, showing the external surface of the cerebrum, or large brain. a, a, is the scalp turned down; b, b, b, the cut edges of the skull bones; c represents the dura mater, or membrane enclosing the brain, lifted up by a hook, exposing the brain; d represents the left hemisphere of the brain; f represents the deep cut or fissure between the right and left sides of the brain, which divides the organs of the brain into pairs, as above stated.HBH 105.2

    252. Does all the substance called the brain lie in the head?HBH 105.3

    No; the animal nerves are only small strings of the same substance, running from the top of the head to the very extremities of the body.HBH 105.4

    253. Which is the largest nerve in the body?HBH 106.1

    The spinal marrow, which is situated in the center of the spine or back bone; extending from the middle of the brain, down between the arms, through the neck and spinal column.HBH 106.2

    254. Does this large nerve send out smaller ones through the body?HBH 106.3

    Yes, in great numbers; some of these nerves also extend from these great nerves to the ears, eyes, nose, tongue, etc. The nerves give us feeling; without nerves we should be without feeling. If we had no nerves connecting the eye with the brain we could not see. We could not smell or taste if there were no nerves connecting the nose and tongue with the brain. If a nerve is cut or destroyed the organ to which it is attached loses its function entirely. If the nerves connecting the hands with the head were destroyed, our hands might be burned in the fire and we would have no consciousness of pain or suffering.HBH 106.4

    255. How many coverings are there to the brain?HBH 106.5

    There are three. The first or outer covering is the dura mater of the brain; see a, Fig. XIV. It is a strong, whitish, fibrous membrane, which adheres to the internal surface of the cranium, or skull. From the internal surface of the dura mater, portions extend inward to support and protect different parts of the brain, and externally, other processes extend outward for sheaths for the nerves passing out of the skull and spinal column. The second membrane is the middle covering; it is very thin and transparent. It surrounds the nerves until their exit from the brain. The third is the pia mater, and is the internal covering, consisting of numerous blood-vessels held together by thin layers of tissue. It invests the whole of the brain and each of the windings, by extending through all the fissures between them. The pia mater is the nutritive membrane of the brain. It is through its blood-vessels that arterial blood is distributed, which is received from the arteries entering the front and back parts of the skull.HBH 106.6

    256. What part of the brain is called the cerebrum?HBH 107.1

    That portion which is seen in Fig. XIV. It is divided into the right and left hemispheres by the line f. Each of these hemispheres is divided on its under surface into front, middle, and back lobes. The surface of the cerebrum, as you may see, presents a number of slightly-convex elevations.HBH 107.2

    257. What is the cerebellum?HBH 107.3

    The cerebellum contains about one-sixth or one-seventh part of the brain. It is pear-shaped, and is attached to the cerebrum by a band of thick fibers. It lies directly beneath the cerebrum in the back of the head.HBH 107.4

    258. What seems to be the order of development of the cerebro-spinal nerves?HBH 107.5

    1. The spinal nerves, commonly described as those arising from the spinal marrow, but which probably preside over the formation of that nerve. 2. The spinal marrow itself. 3. Those ganglia of the brain which are essential to the functions of taste, smell, hearing, and sight, together with the special nerves by which these functions are performed. 4. The ganglia which constitute the mental and moral faculties. 5. The cerebral hemispheres themselves.HBH 107.6

    259. What is the spinal marrow?HBH 108.1

    The spinal marrow is that soft substance which lies in the hollow of the back bone, and is composed of the white and gray substances. It is naturally divided longitudinally, into a right and left half; each of which consists of a front and back column, so that the whole marrow is composed of four columns, or rather of two corresponding pairs; as the two front portions correspond with each other in form and character, and the two back ones correspond also with each other. They constitute a double spinal marrow, and give to each half of the body an independent existence so far as the spinal marrow and its nerves are concerned. And for this reason it is, that one whole side of the body may be paralyzed, while the other remains in full possession of its powers. The spinal marrow is enveloped in three different membranes, corresponding to the three enclosing membranes of the brain. Connected with the spinal marrow, through small intervertebral openings formed for the purpose, on each side of the spinal canal, are thirty pairs of nerves, which are called the spinal nerves. A portion of the filaments which compose each spinal nerve rise in the back portion, which are the nerves of animal sensation, some of these go to the muscles of voluntary motion and convey to the mind information concerning the motion of those muscles, and thus enable the mind to regulate their motion. The rest run to the outer skin of the body, and are the nerves of sensibility or feeling on its surface. Branches of these nerves run to the fingers’ ends, where they are highly sensitive to the touch. The filaments of nerves that arise from the front portion of theHBH 108.2

    PICTURE AND TEXT

    spinal marrow are nerves of motion. These convey the stimulus of motion, in obedience to the will, to the voluntary muscles, causing them to contract. Although these filaments start from opposite sides of the spinal marrow, they unite into one cord, almost immediately on leaving it, and go in one cord to their muscles, yet these filaments may be traced distinctly by the anatomist on dissecting the cord. The spinal marrow seems to be a connecting link between the brain and the various nerves of the body, or, as it were, a protected thoroughfare through which the mandates of the will may be carried to the body, and information carried back to the mind.HBH 109.1

    Figure XV
    PICTURE
    CRANIAL NERVES

    260. What is the medulla oblongata?HBH 110.1

    The spinal marrow, d, Fig. XV, passes upward through an opening in the base of the skull, extending about an inch into the cranium. The head of the spinal marrow is divided into six parts, or three pairs of bodies. Two on the front called the pyramidal bodies. Two behind, called the restiform bodies. Two at the sides called the olivary bodies. Besides these, a strip of medullary matter, which is the origin of the several nerves particularly associated in the function of respiration. These pairs of bodies are united in a single bulb, about one inch in length, and about two-thirds of an inch in diameter, and is commonly called the medulla oblongata. From the sides of this bulb, rise, as may be seen in the above figure, several pairs of nerves, and from its top arise all the other parts within the cranium.HBH 110.2

    261. What is the arbor vitae?HBH 110.3

    When either lobe of the cerebellum is cut, it presents a tree-shaped arrangement of marrow-like matter, called arbor vitae. It is seen in Fig. XV, just back of the medulla oblongata. A gray mass in the trunk of this tree, with saw-like edges, is called the corpus dentatum.HBH 110.4

    262. What is the arrangement of the ganglia of the brain?HBH 110.5

    By looking at the brain from below, we begin with the medulla oblongata (see Fig. XV), to the back part of which are added the cerebelli, from the right to the left of which, around the upper part of the oblongata, extends the pons, above which other ganglia are placed. Some of the fibers from the cord nerves extend into them all, and into the cerebelli, while the remainder extend upward and forward into the great ganglia.HBH 110.6

    The cerebri are, so to speak, folded back, over, upon, and by the side of, the other parts, slightly overhanging the cerebelli, but quite covering in the central ganglia. Where the surfaces of the cerebri come in contact with the central ganglia, they do not adhere to them, but both surfaces are free, and moistened with the same fluid, as if they had not been thus placed. These places where they thus come in contact are called ventricles. There are several of these ventricles in the brain. A dissection of the brains of inebriates frequently discovers these ventricles filled with alcohol. In dropsy of the brain there is a collection of watery fluid in these ventricles. Sometimes, however, the water is outside the brain, in which case the skull may be tapped by a skillful surgeon. The most dangerous cases are when the water is in the ventricles.HBH 111.1

    263. How many pairs of nerves are embraced in what are called the cranial nerves?HBH 111.2

    There are nine pairs of them, all of which, in Fig. XV, are marked numerically, as they are named. 1 is the olfactory nerve, the nerve of smelling. Nerves pass off from this which are distributed upon the mucous membrane of the nose. 2, optic nerve, the nerve of seeing. It comprises two large cords, extending from the medulla oblongata. At its front end it extends into the nervous membrane called the retina. This nerve is always present where the faculty of vision exists. 3, 4, are nerves of motion connected with the eye. These go to the muscles which serve to roll the eye, and direct the pupil toward the object of vision. 4, is used to give a pathetic expression to the eye, and hence is called the pathetic nerve.HBH 111.3

    5, with its branches, is called the trifacial nerve, and is distributed to every part of the face, forehead, eyelids, lips, nose, jaws, and ears. It unites freely with the facial, and several other nerves of the head, and with a great many twigs of the nerves of organic life. It communicates with the organs of all the five senses, and brings all the parts with which it is connected into a direct and powerful relation with the stomach and the whole domain of organic life. This nerve is connected with all the nerves of the teeth; this explains why decaying teeth may give rise to head-ache, ear-ache, etc. This nerve being connected with the pneumogastric nerve of the stomach, both are affected in that distressing malady sick head-ache. This, you will see, is the largest nerve of the cranial group. 6. These are also nerves of motion connected with the eye. These nerves when paralyzed, cause squinting. 7. The seventh pair are facial and auditory nerves, and are connected with the chin, lips, angles of the mouth, cheeks, nostrils, eyelids, eyebrows, forehead, ears, neck, etc. It is on these nerves that the expressions of the face depend. 8. The eighth pair of nerves consists, as may be seen, of three classes of nerves; glosso-pharyngeal, pneumogastric, and spinal accessory. The glosso-pharyngeal, or tongue-and-pharynx nerve, is distributed to the mucous membrane at the base of the tongue, to the tonsils and mucous glands of the mouth, and to the throat. When this nerve is paralyzed the voice is destroyed, and the act of swallowing hindered. The pneumogastric, or lungs-and-stomach nerve, forms connections and plexuses with almost every nerve in the region of the throat, neck, and thoracic cavity, to such an extent that it has been called the middle sympathetic nerve. It sends branches to the pharynx, or top of the meat-pipe; to the larynx, or organs of voice at the top of the wind-pipe; to the wind-pipe in all its branches and whole extent. It sends branches to the plexus of the heart, to the plexus of the lungs, some twigs to the solar plexus, and to the plexuses of the liver and spleen. But the main body of this nerve descends to the stomach, and is distributed over that organ, uniting extensively with the nerves which come from the solar plexus. The spinal accessory seems to be connected with the muscles essential to the production of voice, and is also connected with many branches of the spinal nerves. The ninth pair of nerves regulate and control the muscles of the larynx, or organs of voice. It is a nerve of motion to the tongue, controlling in a measure its use in speech. It is connected with the eighth pair, and many other nerves of the upper portion of the body.HBH 112.1

    264. What are the spinal nerves, and how many pairs are there?HBH 113.1

    The spinal nerves are so called because they take their origin from the spinal cord. There are thirty-one pairs of them; they furnish the principal nerves to the trunk, back, and extremities. The spinal nerves are divided into cervical, dorsal, lumbar, and sacral. The cervical consists of eight pairs, connecting with the upper extremities. The dorsal has twelve pairs, which are connected with the back, chest and abdomen. The lumbar nerves are five pairs, and the sacral nerves six pairs. These are connected with the lower portions of the body, the thighs and legs. There are also what are called sacral nerves, which are connected with the leg, and foot. These are in their divisions nerves of sensation and motion to the legs and feet. These spinal nerves convey impressions made at the surface of the body, including the extremities, to the brain, and transmit impulses to the muscles from the brain.HBH 113.2

    265. What is the great function of the brain?HBH 114.1

    It is the organ or instrument of the mind, and that by which the mind performs all its operations. It is the seat of all the intellectual and reasoning faculties of man, such as memory, hope, love, hatred, ambition. The brain is the seat of all sensation and knowledge, and the mind obtains its knowledge of all outward objects by impressions concerning them being conveyed to the brain through the medium of the nerves of sight, hearing, smelling, tasting, and feeling.HBH 114.2

    266. What is the effect of injuring the brain?HBH 114.3

    An injury of the brain will immediately affect the whole system. If the skull is fractured and depressed upon the brain, the person is immediately unconscious, having no thought or sense of objects around him. Instances are on record, where the brain has been injured, the person being insensible for several days, and when they were restored again to consciousness, they would speak the remainder of the very sentence they were speaking when they received their injury. If the brain is very seriously injured death will at once ensue.HBH 114.4

    267. Is the brain active during a state of profound sleep?HBH 114.5

    It is not. A person may be touched while in a state of sound sleep and not perceive it, or be conscious of it. When persons dream, they are not in a profound sleep. Dreams are many times in two parts. First, an earnest effort is made to get to some place or to gain some object; then comes a state in which you have no knowledge. Afterward your dream goes on again, with this difference, however: you find yourself at the place, or in possession of the object you were seeking, but hardly know how the feat was accomplished. This break in your dream is the unconscious state of your sleep, or that time when you have no dreams. That sleep is generally the most refreshing to the body, in which we dream the least.HBH 114.6

    268. What persons can get along with the least amount of sleep?HBH 115.1

    Those whose diet is of fruits, grains, and vegetables, and whose habits of life place them most of the day where they exercise in the open air. Persons of studious habits, or who follow in-door labor, require more sleep than those above mentioned. Those who eat but two meals a day, their other habits being right, enjoy their sleep the best, and can get along with a less amount of sleep than those who eat meat, or who eat their three meals a day. John Wesley, with an active nervous temperament, and a vegetable diet, performed extraordinary labors, with only from four to five hours sleep out of the twenty-four, while Daniel Webster, with a more powerful, but less active organization, and with the ordinary mixed diet, slept eight or nine hours.HBH 115.2

    269. What is the proper amount of sleep and the best time to secure it?HBH 115.3

    The great majority of those who have attained to long life were those who slept at least eight hours. The best period of sleep is to retire not long after dark, and to be up with the first rays of morning light. In the cold season, when nights are long, more sleep is required. All persons should make it their rule to retire if possible as early as half-past eight in the evening, and sleep as long as the slumber is quiet, if it be nine hours. Dreamy, restless dozing in the morning is generally more debilitating than refreshing. Those persons who indulge in the use of animal food, or eat gluttonously of any food, or who use spirituous liquors, or tobacco, are in danger of oversleeping, even to producing stupidity of mind, and indolence of body. Sleeping after a meal is always pernicious.HBH 115.4

    270. What should be the condition of the room, beds, and bedding, to secure refreshing sleep?HBH 116.1

    Sleeping apartments should be large, high, and well ventilated. The windows and doors should be so arranged as to allow a free circulation of air, even night air. If the sleeping room is dark or damp, it should be occasionally dried with a fire in the room, but the fire, except in the case of very feeble persons, should be entirely extinguished and the room well aired before retiring in it for sleep. If practicable the sun should be allowed to shine in sleeping rooms some portions of the day. Ventilation of sleeping apartments should not be carried to an extreme. The air should not be allowed to blow directly on the sleeper, but there should be an opening somewhere by which fresh air from out-of-doors can be admitted into the sleeping apartment. In the most-severely-cold weather, say a crack in the window of a couple of inches, and in the warmest weather a door of the room open, and a third or half of the window open. The beds should be of straw, corn husks, or hair.HBH 116.2

    In case of those who are tender, they can use over this bed, a light, thin, cotton mattress. No bed should be soft enough for the body to sink into it. Cotton or hair is much better for pillows than feathers. The bed clothing should be as light as possible, consistent with comfort. Linen or cotton sheets are better than flannel. For outside bedding, thin quilts are best in summer, and flannel blankets in addition for winter. The position of the body in sleep should be perfectly flat and horizontal, with the head a little raised; one common-sized hair pillow is generally sufficient. Healthy persons of correct dietetic habits may sleep at pleasure on the back, or gently reclining to one side. All however should carefully avoid reclining nearly on the face, or crossing their arms over the chest, as that brings the shoulders forward, contracts the chest, and materially affects the breathing. Placing the arms over the head in sleep is a pernicious practice.HBH 117.1

    271. Does a proper use of the mind strengthen the brain?HBH 117.2

    It does. The more the brain is exercised, if not overtaxed, the more firm and vigorous will be the operations of the mind; but if the brain is permitted to remain inactive, it will lose its healthy state, and all the operations of the mind must in consequence be dull and sluggish.HBH 117.3

    272. What protects the mass of brain from jars?HBH 117.4

    In early life the elasticity of the frame renders other protection against jars of the brain unnecessary, but as life advances, in addition to the increasing quantity of marrow in the bones, the arachnoid membrane beneath the brain increases in strength by an addition to it of sinewy fibers, which grow between the arachnoid and pia mater of the brain. These are filled with a fluid, and the brain rests upon it as easily as a person lies on a water bed. This cushion has become in old age, in some instances, an inch thick.HBH 117.5

    273. How is the surface of the brain arranged?HBH 118.1

    It is arranged in various winding elevations, which constitute the phrenological organs of the prevailing system of mental philosophy of the present day. As the brain is divided into right and left hemispheres, so all the organs of the brain are double. All phrenologists regard the cerebral portion of the brain as the seat of all the mental and moral powers, and the cerebellum as the seat of the sexual impulse. The cerebellum is also regarded as the generator of nervous influence to the muscles of locomotion. The whole brain, though the seat of sensibility, is itself wholly insensible. Any part of it may be cut, pricked, torn, or removed, without producing pain.HBH 118.2

    274. What is the mind of man?HBH 118.3

    It is the aggregate of all the functions of the brain. These are mental powers. The mental powers may be distinguished as faculties and propensities. The faculties together constitute the intellect. They are the powers concerned in thought and the formation of ideas, the thinking and knowing part of the mind. The faculties are divided into perceptive and reflective. The perceptive take cognizance of individual things and their mechanical properties, and are the functions of observation. The reflectives arrange, compare, and analyze subjects, and trace out their relations of cause and effect. These are the reasoning organs. The propensities are the feeling organs. They are the impulses, emotions, or passions, which impel us to action. The intellectual faculties devise means, seek out objects, and study methods to gratify these feelings or propensities. When the faculties have discerned the object, or ascertained the manner of satisfying the impulse or propensity, the will determines its instrumentalities-the bodily structures-to act in relation to its possession or enjoyment. Mind then, consists of faculties and feelings, or affections and thoughts.HBH 118.4

    275. Are the phrenological organs alone, a true index of moral character?HBH 119.1

    No. The cerebral portion of the brain, called the organs of the propensities, hold a more immediate relation to the physical condition of the nerves of organic life than do the intellectual faculties; so whatever increases the direct influence of the domain of organic life on the cerebral organs, proportionately increases the influence of the propensities over the intellectual and moral faculties. As the organs of destructiveness, combativeness, acquisitiveness, and amativeness, hold more near and special functional relations to the organic system of nerves, they are more readily excited by the excitement and irritation of the nerves of organic life. This being the case, it is more difficult for the intellectual faculties to weigh correctly evidence presented to it, and to arrive at conclusions of truth, and for the moral faculties to preserve their functional integrity in an excited condition of the organic nervous system, than when they perform only their healthful functions. So to form a correct knowledge of character from the organs of the brain, the state of the organic nervous system must be inquired into, as well as the general habits of the individual, as these all tend to modify greatly the character of the person. Cases are on record of persons whose phrenological developments alone would indicate them as among the best members of society, but whose intemperate habits so excited their destructive animal organs that they were mere beasts, seeking to destroy their best friends. All excess in stimulation will thus injure the mind, in proportion to the extent of organic nervous irritation.HBH 119.2

    276. What is true happiness?HBH 120.1

    All true happiness is that condition of mind which is the result of right feeling. The healthful exercise of all the mental powers is the condition to secure right feeling. Health of body and health of mind is happiness. A healthy condition of body is essential to health and strength of mind, while a healthy condition of the mind is happiness. This condition is one in which all the organs and propensities are in subjection to the man, and he governed in his course by right principles. The person then recognizes the hand of his Creator, and is led by the healthy action of his moral faculties to render to God due homage. Many, failing to see the connection between mind and body, attribute all their mental depression to the power of the Devil, or their own sins; yet these conscientious souls cannot tell really what these great crimes are. If they viewed matters in their true light, they might save themselves from despair. While realizing the goodness of God, and his tender mercies over all his works, and while trying to do every duty made known to us, and realizing our own feeble condition of body, we should learn to attribute a larger measure of our disconsolate feelings to the depressing power of disease, and less of it to the special frown of God upon us.HBH 120.2

    277. How and why are mind and body each affected by the condition of the other?HBH 121.1

    Because of that close sympathetic connection between the brain and all other parts of the system, or between the nerves of animal and organic life. Although, as before said, in health, the animal nerves have no direct control over the functions of those nerves that preside over the building up of the system, yet, there is such a sympathetic connection between them, that any violation of the healthy action of either affects the other. Excitement of the mind, or violent passion, affects the whole domain of organic life, and in some instances death is instantly induced. Such excitements and irritations frequently repeated lead to change of structure in the organs, and hence to disease. While the nerves of organic life are preserved in a healthy state, the mind is serene and cheerful, as in healthy childhood; but when these nerves are deranged, we are unhappy, we know not why. We long for relief, we know not from what. We would go, but we know not where. We would cease to be what we are, yet we know not what we would be. We look around for the cause of our grief, but in vain; we cannot find it, and conclude it must be God’s displeasure for our crimes. This feeling is indulged until despondency like the pall of death enshrouds us, and envelopes us in its myriad folds. The brain and spinal marrow, and in fact all the nerves of the body, are nourished by blood-vessels over whose functions the nerves of organic life preside, so it is evident there is a close connection between the two systems.HBH 121.2

    278. What seems to be the connecting link between these two systems of nerves?HBH 122.1

    As before stated, the center of the system of animal nerves is the brain, and as we see by Fig. XV, the top of the medulla oblongata is the grand point from which these nerves all proceed, and the seat of the sensorial power in the system. The solar plexus is the center of the system of organic nerves. The pneumogastric or lung-and-stomach nerve, which passes directly from one of these centers to the other, and forms plexuses, and connections with so many of the organs of the vital domain, seems to occupy a middle ground between the nerves of organic and animal life. This is the nerve which establishes a most powerful sympathy between the brain and stomach. This nerve is probably the greatest connecting link between the two systems.HBH 122.2

    279. What organ of the body is most readily affected by the mind and by derangement in the organic nervous system?HBH 122.3

    The stomach, from its connection with the organic life center, and with almost all parts of the body by the pneumogastric nerve, sympathizes more directly and powerfully with every other organ than any other part of the body. So, for the same reason, every other part sympathizes powerfully with the stomach. Chronic indigestion impairs the functional power of the external skin. Excessive heat or cold on the surface, on the other hand, impair digestion. The most powerful sympathy exists between the brain and stomach. Intense and protracted, or excited and impassioned exercise of the mind, affects all the functions of the organic domain. It causes a sensation to be felt in the epigastric center. This sensation is usually referred to the heart, but the stomach more than any other organ is the seat of it. It is in a great measure through the stomach that other organs are affected by mental influences. Derangement of the stomach affects the liver, intestinal tube, and other internal organs.HBH 122.4

    280. What most readily affects the condition and powers of the mind?HBH 123.1

    The condition of the stomach and alimentary organs. The worst cases of insanity result from a deranged state of the organic nervous system, especially the stomach and intestines. This deranged state of the nerves of organic life constantly calls up in the mind improper thoughts and conceptions. The brain all the while may be in a perfectly healthy condition. That the real seat of insanity is in the nervous system instead of the brain may be seen in the fact that many instances are on record of insanity when the brain itself was not diseased except sympathetically. So also instances are cited where large portions of the brain were diseased and no derangement ensued. Again, cases where persons with debilitated stomachs were thrown into a state of derangement by eating a meal of pickled cucumbers. One of the greatest causes of insanity is loss of sleep.HBH 123.2

    281. What is the comparative consistency of nerves in different periods of life?HBH 123.3

    In early life the nerves are soft and pulpy. The brain itself is not in a condition to be applied to mental labors till about seven years of age. At the age of forty the nerves become smaller and dryer.HBH 123.4

    282. When is the best time for study?HBH 123.5

    In the morning, for then the brain is rested. The morning is also the best time for physical exercise.. We should attend to the physical exercise first, and devote the remainder of morning hours to study. Physical health must be attended to, for if health fails all mental exercise to any extent is at an end. Exercising in the morning before commencing study will tend to preserve and invigorate health.HBH 123.6

    283. Is the nervous system easily diseased?HBH 124.1

    The main thing necessary for the general welfare of the nervous system is to attend to the general health of the body. If a person has nothing on which to exercise his nervous energy he is liable to disease. Employment of some kind is indispensable to the health of the nervous system. Long-continued trains of thought, however, are to the brain, what working one set of muscles incessantly all day, is to them: complete exhaustion. He that would last the longest, must occasionally turn his thoughts from his ordinary avocation completely, and give the brain rest. Every one, whether business man, student, farmer, or mechanic, needs a vacation once or twice a year, when, for a few days or weeks, he may break up the ordinary routine of life. To have a healthy condition of the nervous system, it is proper that the mind should have a variety of objects on which to dwell. Its efforts, however, should not be made spasmodically. There should be system; not working the brain to its utmost tension for a time, and then letting it lie idle, but working regularly and steadily.HBH 124.2

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