Certain points on the surface of the body are spoken of  as "Centers." This word has become a part of the osteopath's technical vocabulary.   It does not convey  to the mind of the osteopath the same meaning which attaches to it when used in physiological textbooks.

    A physiological functional center in the central nervous system is that point where the action of a certain viscus or other structure is governed.

    An osteopathic center is that point on the surface of the body which has been demonstrated to be in closest central connection with a physiological center, or over the course of a governing nerve bundle.

    In Chapter III, under the subheading segmentation, reference is made to the division of the central nervous system into sections which may, to a moderate degree, functionate independently.  No  portion of the nervous system ever functionates absolutely independently.  The action of every portion affects all other portions, but certain areas in the brain and spinal cord seem to be somewhat set apart to govern or coordinate the physiological activity of certain organs.  Physiology has demonstrated a large number of these centers.

    "Physiology shows how not only the individual ganglia which lie in the intestines function with relative independence, but how even structures like the spinal ganglia frequently reckoned in with the central nervous system still enjoy relative independence from it functionally."

    "What we know of the anatomical structure and of the functions of the central nervous system of vertebrates forces its more and more to tile conclusions (1) that even individual parts of the central system are themselves in a position to function to a certain extent independently, and (2) that even the brain and spinal cord of vertebrates are composed of a series of centers.  Whether the one or the other of these is more highly developed, whether they are in connection with deeper centers, whether they have connections among themselves and with higher centers, determine the measure of the higher or lower development of the central system.  We will find later, that in the course of the development of a class, individual centers connected with the  central system have reached a high development, while others have arrived at a certain stage (or reached a certain type) where they remain stationary, and throughout all subsequent posterity remain everywhere alike.

    "One can conceive that in its essentials every nervous system is composed of afferent tracts and efferent tracts, and of tracts which form the connection of the elements among themselves."

    Anatomy and Physiology demonstrate that from a certain segment of the spinal cord nerve fibers are distributed to skin, skeletal muscles, involuntary muscles and mucous membrane of viscera, and to the muscular coats of the arteries supplying all these structures.

    Physiology and Pathology demonstrate that impressions made upon sensory elements in skill, mucous membraine, muscle, or other structures, are carried to a center in the central nervous system.  These impressions are coordinated in this center, and affect the physiological action of all structures innervated from the same center.  When we speak of two or more structures being in close central connection, we mean that they are innervated from the same segment of the central nervous system.

    Diagnosis. - In diagnosis these segments serve the purpose of calling the osteopath's attention to the condition of several correlated structures.  For example: A hyperaesthesia at any point along the spinal column fixes the attention of the osteopath upon all the structures of the body which are innervated from the segment of the central nervous system which furnishes nerves for this oversensitive area.  Examination of all the structures thus supplied will probably discover the point chiefly affected.

    In order to give the student a clear insight into the principles underlying osteopathic diagnosis, we will examine the osteopathic centers serially, commencing at the atlas.

    First Four Cervical Nerves. - We will first divide the spinal column into sections according to the location of certain groups of nerves.  Remember that these divisions are made with reference to the points of exit of the spinal nerves from the spinal column.

    The first section contains the first four cervical nerves.  The first cervical nerve leaves the spinal canal between the occipital bone and the atlas.  A study of its distribution will inform us what structures are governed by it.  Its anterior division forms a part of the cervical plexus.  This division communicates with the sympathetic nerves on the vertebral artery, the pneumogastric, the hypoglossal, and superior cervical sympathetic ganglion.  It innervates the Rectus Lateralis and Anterior Recti.

    The posterior division of the first cervical nerve is called the suboccipital.  It supplies motor fibers to the posterior Recti muscles of the head, the Superior and Inferior Oblique, and the Complexus.  Sensory fibers from the scalp form part of this nerve.

    Example of Hilton's Law. - With this outline of distribution before us, we can note some of the results of stimulation of this nerve.  Since the anterior division supplies a few fibers to the occipito-atlantal articulation, we have an example of Hilton's law of distribution of a nerve trunk.  The synovial membrane of the occipito-atlantal articulation, the muscles which govern movements of the joint, and the skin over the joint are all innervated by this first cervical nerve.

    The muscles moving the occipito-atlantal articulation act according to impulses reaching the point of origin of the first cervical nerve over sensory fibers ending in the skin covering the back of the head and this articulation, also from those ending in the synovial membrane of the joint.  These impulses are coordinated in higher centers of the brain which govern equilibration.  The muscles of this joint act also according to our will.

    The Pneumogastric Nerve. - Furthermore, the anterior division of this nerve communicates with the pneumogastric, hypoglossal, and the superior sympathetic ganglion.  The pneumogastric has such a wide distribution that we cannot afford to follow all of its paths of influence at this time.  The student is referred to any extended work on anatomy for the details.  The muscles and mucous membranes of the larynx are innervated by the pneumogastric, hence any irritation of the larynx may reflex impulses to the center of origin of the first cervical nerve and cause undue contraction of the muscles innervated by it.  This muscular contraction can result in changing the relation of the bones forming the occipito-atlantal articulation until a condition exists which we call a subluxation of the atlas.  Having followed the impulses from the larynx to the center of coordination and out again to the muscles of the occipito-atlantal articulation with consequent subluxation, we may profitably note the fact that sudden temperature changes may affect the skin over these muscles, arousing impulses which are carried to the center of coordination, thence to the muscles, causing them to contract with resulting subluxation.  Some of the reflex impulses may find their way to the larynx and cause congestion of its mucosa.  The atlas may be subluxated by violence, then the sensory impulses originate in the synovial membrane of the joint and in the muscles moving the joint.  These impulses may be reflected in such manner as to affect the larynx, pharynx and other structures innervated by the pneumogastric.  The reflex influences existing between the first cervical nerves and the pneumogastric are chiefly confined to the larynx and the pharynx, because spinal nerves usually receive sympathetic reflexes from the segment of the body which they cover.  If we should follow all of the divisions of the pneumogastrics, we would find a  wonderful diversity of distribution.  We do not expect that reflexes from the heart, lungs, stomach, etc., are going to be subject to coordination in the area of origin of the first cervical nerve, just because there is communication between the pneumogastric and this nerve.  The pharynx and larynx are, in part, structures governed involuntarily, and hence they are in large part removed from the influence of nerves carrying voluntary impulses, i. e., spinal nerves.  The pneumogastric is essentially sympathetic in character.  The tissues of the larynx and pharynx are practically under the influence of the first cervical nerve.  Your attention is called to Hilton's law as he has stated it in relation to mucous and serous surfaces.  "This same principle of arrangement, anatomically, physiologically and pathologically considered, is to be observed, with an equal degree of accuracy in the serous and mucous membranes.  Thus considered, it presents a principle which, if it has any application in practice, must be one certainly of large extent."

    Since the spinal accessory forms part of the pneumogastric above the point of communication between that nerve and the first cervical, we can perceive the reason for the great influence which temperature changes, affecting the skin over the sterno-cleido-mastoid and trapezium muscles, have on the action of the muscles forming the suboccipital triangles.  The spinal accessory innervates the stemo-cleido-mastoid and trapezius.  These muscles will contract reflexly when the sensory nerves in the skin over them are affected by temperature changes.  The action of these muscles affects the position of the head chiefly by causing movement in the occipito-atlantal articulation whose accurate adjustment depends on the muscles innervated by the first cervical nerves.

    The point of origin of the first two cervical nerves is probably a bilateral center.  In order to secure coordinated movements, both sides of this bilateral center must act reciprocally, but if the impulses coming into the center from one side are much greater in number and intensity than those entering on the opposite side, this reciprocity of action may be interfered with and subluxation result.

    The Hypoglossal Nerve. - The hypoglossal nerve is the motor nerve to the muscles of the tongue, and to the muscles moving the larynx and hyoid bone.  It communicates with the first cervical nerve.  Movement in the occipito-atlantal articulation affects the relations of the points of origin and insertion of the muscles innervated by the hypoglossal; therefore, impulses passing over both nerves are coordinated at about the same area.

    Superior Cervical Ganglion. - Probably the greatest cause for disturbance along the course of the first cervical nerve is the communication with the superior cervical ganglion and the sympathetic plexus on the vertebral artery.  This communication subjects all the structures innervated by the first cervical to reflexes initiated in various areas of the head, neck and brain.

    The superior cervical sympathetic ganglion has a vasoconstrictor influence over the blood vessels of the head, neck and brain.  It is a well known clinical fact that ice applied to the surface of the neck over the occipito-atlantal articulation will cause constriction of the blood vessels of the brain.  This constriction is a reflex effect due to the communication of the first cervical nerve with the superior cervical sympathetic ganglion.

    Suboccipital Triangles. - When the first cervical nerve is sensitive to moderate pressure over the suboccipital triangles, we may be sure that it is evidence of disturbance of circulation in some part of the head, neck or face.  We look for this disturbance in the structures which are subjected to the greatest amount of work, i. e., the eye, pharynx or larynx.  The brain last, because it is not easily fatigued.  Sensitiveness is nearly always associated with a subluxated atlas, i. e., one is indicative of the other.

    Whether the subluxation is primary or secondary, it is a source of irritation and must be reduced; therefore, in practice, our treatment is applied primarily to this changed structure.  The results of practice prove this to be the best method.

    Patients rarely complain of sharp neuralgic pain in the area of the suboccipital triangles.  A dull ache or tension is the usual subjective symptom.

    We have described the characteristics of this center with considerable detail in order that the student may understand how thoroughly an accurate knowledge of anatomy and physiology enters into the work of the osteopath.  Every center must be understood in this same manner.  We do not deem it necessary to go into such detail in describing all of the remaining centers in order that the student can understand their significance.

    In order to make the characteristics of the first cervical nerve stand out prominently, we have described it as though it were individual in its action and reaction.  This is not strictly true.  Analysis compels us to note ill-defined separations in the nervous system.  In order to get a right conception, we must view the first cervical nerve as only one of a group of four cervical nerves which act in harmony.

    Cervical Plexus. - The first four cervical nerves are interwoven to form a plexus.  Each distributive branch from this plexus probably contains some communicating fibers from the four primary nerve trunks.  Viewing the plexus as a whole, we find that its branches are distributed according to Hilton's law.  They innervate the skill of the neck as low as the fifth cervical spine posteriorly, then obliquely forward as low as the sterno-clavicular articulation anteriorly, and the acromio-clavicular articulation laterally.  The skin of the posterior surface of the cranium and the ear receives sensory fibers from this plexus.  These are the gross points to be remembered concerning cutaneous sensory distribution from this plexus.  The muscles under this cutaneous area all receive motor fibers from the first four cervical nerves.

    Anatomists divide the cervical nerves into anterior and posterior then divisions, then describe these separately.  This is an artificial division which does not serve any useful purpose for us. It multiplies detail without giving an adequate conception of the real character of the whole nerve.  When you study the ultimate distribution of the anterior division of a nerve forming the cervical plexus, do not fail to remember that the ultimate distribution of the posterior division is a part of the same nerve.  If the anterior division communicates with a sympathetic ganglion, the posterior division receives impulses from and sends impulses to this ganglion.  If the anterior division communicates with the vagus and hypoglossal nerves, the posterior division is a party to this communication and in all ways benefits or suffers by it according to the number and intensity of the stimuli applied at any point along the course of either nerve.

    This upper portion of the neck is the most flexible part of the whole spinal column.  It is subjected to more changes of temperature and more strains or twists than other portions of the spine.  The constant effort to save the head from injury puts a severe tax upon the activity of the muscles moving this portion of the spinal column.  Subluxations of the atlas and third cervical are quite frequent.  Muscular lesions, contractions, are found here in connection with functional disorders of many kinds located in the brain, eyes, ears, nose, mouth or throat.  Almost invariably a relaxation of these contractions will be a necessary step in relieving disorders in the areas named.

    Intensity of Reflexes. - Individuals differ greatly in the intensity of their reflexes.  Anatomically considered, the connections between the sympathetic and cerebrospinal systems are alike in all individuals, but physiologically considered, there is a vast difference in the degree of independent functioning of these systems.  Patients will be found whose symptoms and lesions do not show any marked tendency toward reflexing impulses from one system to the other.  The sympathetic nerve cells may be so vigorous that severe lesions affecting cerebro-spinal nerves do not in the least disturb the rhythm of the sympathetic system.  Likewise, severe functional disturbances may exist in the area of the sympathetic control without causing very definite conscious sensations.

    The Spinal Accessory. - The sterno-cleido-mastoid and trapezium muscles are innervated by the spinal accessory.  This nerve arises from the spinal cord as low as the sixth cervical, therefore its impulses are coordinated with the cervical plexus in the area of its normal control.

    The Phrenic Nerve - Hiccough. - The phrenic nerve is the motor nerve from the cervical plexus.  It innervates the diaphragm.  It is formed by branches of the third, fourth and fifth cervical nerves.  The position of this nerve in its course along the anterior surface of the scalenus anticus, makes, it convenient to apply direct inhibitory pressure over the nerve trunk.  This pressure has a restraining influence over the impulses traveling to the diaphragm; therefore, we inhibit to stop hiccough.  We have treated cases in which inhibition was of no avail.  In such cases a strong movement of the head and first three cervical vertebrae, as a solid lever, to secure rotation and relaxation between the third and fourth cervical vertebrae may give good results.  Since hiccough is a reflex due to stimulation of sensory nerves, especially the pneumogastric, it should not be expected that inhibition of the motor nerve, phrenic, would entirely stop hiccoughs while the sensory stimulation is continued.  Clinically, we find that inhibition of the phrenic nerve is sufficient to stop the ordinary case of hiccoughs.  Therefore, we call the area over the course of the phrenic nerve, as it crosses the scalenus anticus muscle opposite the fifth cervical transverse process, the "center for hiccoughs." See Fig. 266.

    The Trapezius and Splenius Capitis et Colli Muscles. - The cervical plexus communicates with the brachial plexus; therefore we expect that those large muscles, such as the trapezium and splenius, which are innervated by nerves from segments of the spinal cord, at various levels, will transmit by their action the influence reflexed to them at the point of their serial innervation.  The spinal accessory innervates a large part of the cervical fibers of the trapezium.  The third and fourth cervical nerves send branches to this muscle.  Therefore any disturbance along the course of these nerves, or along the course of other nerves in, close central connection with them which may cause abnormal contraction of the trapezium, will influence, more or less, all the points of attachment of that muscle.  The trapezius is seldom abnormally contracted.  Any lessening in the normal range of its action is quickly noted by the patient.  The contractured condition is easily removed by a willed action.  We use the trapezium muscle as a means of transmitting power to various portions of the spinal column, i. e., in our efforts to move one or more vertebrae.

    Vasomotion, Head, Face and Neck. - The superior cervical ganglion communicates with the first four cervical nerves, therefore the area over the spines of the first four cervical vertebrae is called a vasomotor center for the head, face and neck.

    Affections of the Cervical Nerves. - These upper cervical nerves are seldom paralyzed.  Paralysis in this region would stop the action of the diaphragm.  Neuralgia may affect the nerves of this group.  Spasmodic contraction of the muscles innervated from this area is not uncommon.

    Brachial Plexus. - The four lower cervical nerves arise from the cervical enlargement of the cord and form the brachial plexus with their anterior divisions, while their posterior divisions supply motor fibers to muscles on the sides and back of the neck, and sensory fibers to the skin over these muscles.  The anterior division of the first dorsal nerve forms a part of the brachial plexus.  Fig. 33 illustrates the superficial area in which the reflexes from the skin and muscles of the arm are manifested.  Subluxations or muscular contractions, in this area may affect one or more branches of this plexus.

    Affections of the Brachial Nerves. - Neuralgia, paralysis or spasm may affect the area innervated by this group.  Cervico-brachial neuralgia is quite common.  A lesion will usually be found affecting the painful nerve at its point of exit from the spinal column.  Paralysis rarely affects this plexus independently, of the nerves leaving the cord at a lower level.  Spasm is represented by such a condition as writer's cramp.

    Lesions causing cramp or neuralgia may be located at the point of exit of the nerve from the spinal column, but the clot or other pressure causing paralysis is usually located in the brain.  Paralysis of the brachial plexus is a part of a hemiplegia; it does not occur independently of the more general condition.  Paralysis of certain groups of muscles of the arm, forearm or hand can usually be traced to the direct injury of individual nerve trunks in the arm.

    Hemiparesis Below Fifth Cervical Vertebra. - Figures 34, 35 and 36 illustrate the results of pressure upon the spinal cord at a point between the fourth and fifth cervical vertebrae.  The child was not very strong at the time of the injury.  A slight fall, while playing, subluxated the fifth cervical.  No notice was taken of this slight fall.  The next day, while bathing the child, the mother noted a peculiarity in the position of the shoulder.  The arm could not be raised above the head.  The author examined this case the day the mother discovered the change in the shoulder.  At first glance from the side, it appeared to be a sub-spinous dislocation of the humerus, but palpation disproved this.  Careful examination showed a hemi-paresis of the whole left side below the fourth cervical nerve.  None of the normal movements were lost, but it required the utmost effort of the patient to make them.  Now and then the left toe would strike the floor too soon and slightly trip her.  Palpation of the fifth cervical vertebra showed a lateral subluxation.  The slightest pressure at this point caused the patient to cry out with pain.

    After our examination (these photographs were taken at that time) the child was taken to a surgeon, who prescribed a surgical operation to stitch the latissimus dorsi to its proper position on the lower angle of the scapula.  He did not recognize the paretic condition of the whole left side.  After a short time, the child was brought to us for treatment.  Our sole effort was to reduce the subluxation of the fifth cervical vertebra.  The tenderness was so great that this was manifestly out of the range of possibilities with a delicate child.  After two weeks of relaxing around this articulation a direct movement was made to reduce the subluxation.  The alignment was perfected, but no immediate good results were noted.  A continued increase in nerve power has gradually, in large measure, overcome the deformity.

    Subluxation of the Scapula. - The deformity is the effect of uneven contraction of muscles.  The latissimus dorsi, rhomboids and serratus magnus are weakened while the levator anguli scapuli and cervical fibers of the trapezius are contracting with their customary power.  The muscles innervated by nerves from above the lesion are acting normally, but their action is not resisted.  This results in subluxation of the scapula.

    The Nerve of Wrisberg. - A division of the first dorsal nerve forms the first intercostal nerve.  The inner side and back of the arm receive cutaneous branches from the first dorsal nerve.  There is communication between the cutaneous nerves to this area and the second intercostal nerve by means of the nerve of Wrisberg, hence pain is frequently felt along the inner surface of the arm in cases of heart trouble, intercostal neuralgia in the second space, or pleurisy.

    The Interscapular Region. - The division of the spinal column between the first and seventh dorsal vertebrae is commonly called the interscapular region.  It  is an exceedingly important one.  It is sometimes called the pulmonary region, because it is the area from which the lungs derive many nerves.  Sensory impulses from the lungs are coordinated in this area.

    Figure 37 illustrates the anterior surface outline of the lungs, while Fig. 38 shows the outline on the posterior surface of the thorax.  These markings were made on the surface according to physical methods of diagnosis.  They represent the average position of the lungs in a healthy man.

    Lung Center. - Figure 39 illustrates the lung center within which sensory impulses from the lungs are coordinated.  A large proportion of cases of bronchitis, pulmonitis or pleuritis of either the simple or bacterial types, are accompanied by great sensitiveness in this area.  This sensitiveness is in the contracted muscles, or, when the shape of the thorax is greatly changed, at the angles of the ribs.   Subluxations of ribs or vertebrae in this area are sometimes found in connection with the inflammations above named.  Whether they are the cause or the effect of the inflammation can only be told by the history.  Because the two conditions, that is, inflammation in the thoracic viscera and osseous subluxation, exist at the same time is no reason for saying that the subluxation is necessarily the cause of the inflammation.  That is a mere dogmatic assertion which lacks scientific proof.  The condition might be just the opposite.  We do not desire to confuse our readers in the least, but it should be remembered that before making a dogmatic statement such as "disease is the result of anatomical abnormalities followed by physiological discord," we should be certain that our statement is not based oil a series of selected coincidences.  The old saw: "It's a poor rule that does not work both ways," is decidedly applicable to nerve reflexes.

    Cilio-Spinal Center. - Tenderness in this area is not necessarily indicative of physiological disturbance in any thoracic viscus.  Fig. 40 indicates two centers.  The one between the second and third dorsal is called the cilio-spinal center.  Detail concerning this center will be found in the chapter on the Sympathetic Nervous System.

    The fact that the vasoconstrictor fibers to the cervical sympathetic ganglia leave the spinal cord below the second dorsal vertebra shows that some reflexes from the head, face and neck may be coordinated in the interscapular region.

    Heart Center. - The point between the fourth and fifth dorsal spines is noted as a heart center.  We have not found any text-book authority for this statement.  Clinical experience leads the author to locate a heart center at this point.  What the absolute influence of this center is we do not know.  From observation of cases of angina pectoris it appears to be a sensory and vasomotor center for the heart.  Stimulation of this center by a quick percussion stroke of the fingers will bring on all immediate attack of pain in the heart, blueness of lips and finger tips.  Heavy digital pressure at this point relieves the pain.  Steady extension of the whole spinal column does not stimulate such cases, but as the pull is reduced and the vertebrae are drawn closer together, this point is frequently stimulated.  In order to avoid all attack after extension, it is necessary to lessen the force of the pull very gradually and evenly.

    Fig. 41 illustrates the surface markings of the heart.  This organ has three centers. (1) The Pneumogastric nerve exerts all inhibitory influence.  This nerve can be stimulated in the neck.  See Fig. 2,)7. (2) The accelerator center includes second, third and fourth dorsal.  See Chapter VI on the Sympathetic Nervous System. (3) Vasomotor and sensory center is found between fourth and fifth dorsal.

    Stomach Center. - The surface outline of the stomach is given in Fig. 42, while its reflex surface center on the back is indicated in Fig. 43.  This center lies wholly within the pulmonary area, therefore it will be readily noted that there is opportunity for much careful reasoning in order to determine whether a lesion between the first and seventh dorsal vertebrae is connected with disturbance of the lungs, pleura, heart, eyes or stomach.  Clinically, we distinguish somewhat as follows: A lesion covering a large part of this area is probably pulmonary.  A legion in the lower half and extending below the seventh spine is probably gastric in character.  When the lesion is at the third or fourth and decidedly limited, i. e., the tenderness is sharply circumscribed in this area, it is impossible to tell, except by further examination of the heart, bronchi and eyes, to which it belongs.  The experienced diagnostician can frequently estimate the probable relation of a lesion by his power of reading the signs of disease as evidenced by expression, posture and general indications.

    The splanchnic area is a large and important one.  It is indicated in Fig. 44.  We have noted in this photograph the upper connections of the splanchnic nerves in the pulmonary area.  This explains the high position occupied by some reflexes from the first part of the gastrointestinal tract.  Wonderful influences can be secured in this area, over circulation in the abdominal viscera.

    Liver and Spleen Center. - The liver and spleen receive their sensory and vaso-i-notor innervation from the eighth, ninth and tenth dorsal nerves.  The surface markings and center are indicated by Fig. 45.  The liver frequently reflexes its disturbed sensory influences to the right shoulder.  We have noted cases of gastric disorder or enlarged spleen which reflexed sensory impressions to the left shoulder.

    Large Intestine. - Fig. 46 pictures the surface markings of the liver and large intestine.  These average normal outlines should be thoroughly remembered and used when making a physical examination.  The spinal center of the large intestine is indicated by Fig. 47.

    Small Intestine. - The first portion of the small intestine, duodenum, is innervated from about the same area as the liver.  Fig. 45.  It must be borne in mind that the splanchnic area is a large one and comprehends these smaller centers.  Many of these points indicated as centers are the areas which clinical experience has noted in connection with visceral disturbance.  The repeated experience of many cases gives them value for diagnostic and therapeutic purposes.

    Center for Chills. - Within the area indicated by Fig. 48, there is a center usually described is the Eighth dorsal, which has received the name of "the center for chills." Our first observation of the action of this center was in connection with a case of malarial fever.  Heavy inhibition of this area lessened the severity of the chill.  We have observed the effects of inhibition of this center in many cases of chill due to nervousness, onset of La Grippe or other infectious diseases, and to abscess formation.  In all cases the treatment was distinctly helpful to the patient.

    The Language of Pain. - Homeopathic medical practice notes variations in the character of pain and uses these characteristics as indications for the administration of special drugs, as though a nerve fiber expressed a language of pain.  To the osteopathic physician. it is sufficient that a nerve express a disturbance at some point of its course.  This cry of the nerves calls for just one thing, remove the cause.  Search is made for this cause along its entire course, and the course of its connections.

    Osteopathic View of Pathology. - Another particular in which the osteopathic pathology differs from other schools of medicine is in the way we view varying conditions of a viscus.  To the medical practitioner, simple gastritis is a vastly different condition from gastric ulcer.  To the mind of the osteopath, these conditions differ in degree, not in kind.  The same organ, the same blood supply, the same nerves are involved in both conditions, therefore we treat these structures.  Our dietetic treatment takes account of the differing activity of the stomach, but our manipulative treatment does not.

    We apply this same method to all organs.  Our manipulative therapeutics are based on structure more than on function.

    Center for Gall Bladder. - The gall bladder lies under the anterior extremity of the tenth rib.  In cases of gall stone the area of the tenth dorsal spine has been found to be sensitive.  All of the structural and functional changes connected with gall stones have seemed to center at this area, and along the tenth rib.  Fig. 49 indicates the center for the gall bladder at the spine.

    Intestines. - The small intestines are governed from the lower part of the splanchnic area, ninth, tenth, eleventh and twelfth dorsal.  The large intestine is controlled by nerves from the lumbar region.  There is a segmental distribution of these nerves to the large and small intestines.  This segmental arrangement is exemplified in cases of diarrhoea.  If the large intestine is the part affected, our manipulation is devoted to the lumbar region.  Reflexes from the bowels may be found at any point between the ninth dorsal and the fourth sacral.

    In five consecutive cases of appendicitis, the reflex was located at the third and fourth lumbar spines.  Fig. 47 indicates the area concerned in reflexes from the large intestine.

    Uterus. - The position of the arrow in Fig. 47 indicates the point of apparently close connection between the hypogastric plexus and the cerebrospinal system.  This point is frequently the seat of great tenderness which is entirely reflex in character.  All of the pelvic viscera at times send reflexes here.  The uterus more than any other pelvic organ manifests its disturbed condition by tenderness at this point.

    The uterus is such a changeable organ that it is the chief disturber of sympathetic rhythm in a woman's body.  A change in its position causes a change in its blood supply, followed by congestion of its mucosa.  This congested condition sets up a series of impulses in the sympathetic system which may never reach the cerebrospinal system.  They spend their force on the various organs governed by the sympathetic nervous system, the heart, stomach, bowels, etc.  Fig. 55 illustrates the difference in the heart's rhythm in the same patient. The first sphygmogram was taken while the patient had considerable difficulty in moving about on account of the heart's  very irregular action.  The uterus is prolapsed.  Patient has worn a stem pessary for years.  When the patient takes the genu-pectoral position and inhales strongly, while pulling upward on the abdominal muscles there is great relief, but when the heart becomes as irregular as this sphygmogram indicates, she is afraid to take this position.  After twenty-four to seventy-two hours of irregular action, the heart regains its rhythm.  The position of the uterus becomes changed by the moving of the patient in bed.  The perineum is badly torn and the uterine ligaments are greatly lengthened, hence the organ cannot be kept in one position.  She has refused operation.

    Many different points are named as centers for the uterus, but they all rest on the fact that after the organ has initiated a large number of impulses in the sympathetic system, they may be passed to the cerebrospinal system at any point of union of the two systems.

    Ovary and Testes. - These organs receive their sympathetic innervation from the plexus which lies on their arteries.  The ovarian plexus is given off from the aortic plexus which receives fibers from as high as the eleventh and twelfth dorsal ganglia.  Therefore a lesion in the area of the eleventh and twelfth spinal nerves is frequently in connection with the ovaries or testes.
Fig. 50 indicates the height of the influence of the aortic plexus through its direct connection with the cerebrospinal system.

    Kidneys. - Fig. 51 indicates the surface marking of the kidneys and the junction of the last dorsal and first lumbar vertebrae.  Lesions of either the eleventh or twelfth dorsal may affect the kidneys.

    The reflexes of this organ may reach the cerebrospinal system over the renal splanchnic.  The articulation of the last dorsal and first lumbar allows considerable movement.  It is probably the weakest part of the back.  The area of the twelfth dorsal nerve is usually sensitive when the kidneys are affected.  This sensitiveness may extend a short way upward, as far as the tenth dorsal.

    In patients whose abdomen is moderately thin, it is possible to affect the renal sympathetic plexus by deep manipulation above the umbilicus.  The kidneys lie above the level of the umbilicus.  Have the patient lie in the dorsal position with flexed thighs so as to relax the abdominal muscles.  The balls of the fingers of both hands should be pressed deeply into the abdomen about two inches above the umbilicus, then move the fingers laterally toward the kidneys.  Pressure is thus brought to bear upon the renal artery.  The mechanical stimulation of the renal plexus usually results in vaso-constriction of renal arteries.

    Second Lumbar. - The lumbar enlargement of the spinal cord is the physiological center for several functions performed in the pelvis.  Defecation, micturition, and parturition, are all reflexly controlled at this point, second. lumbar.  The spinal cord ends at the lower border of the first lumbar vertebra.  The second lumbar vertebra is indicated in osteopathic literature as a center for the three functions named above.  We understand by this that an injury at this point may involve the functional activity of the rectum, bladder, or uterus.  Disturbances in these viscera are not necessarily manifested to the osteopath by tenderness around the second lumbar vertebra.  Any point along the spinal column below the second lumbar may be sensitive as a result of disturbance in the pelvic viscera.  Fig. 52.

    During parturition there is conscious aching along the whole lumbar area, thus demonstrating that the sensory nerves of the uterus call reflex their irritation to all the lumbar nerves.  Injury of the spinal column at the junction of the dorsal and lumbar portions may affect motion, sensation and nutrition of all the structures innervated by the cauda equina.  An injury below the second lumbar vertebra will not have as far-reaching effect as an injury of the same character above that point.

    Paraplegia. - When the back is broken at the dorso-lumbar articulation, paraplegia results.  It is not necessary to actually break the back in order to cause paraplegia.  A severe strain caused by a fall may induce such an exudate around this articulation that pressure is exerted on the lumbar enlargement of the cord.  Many of the so-called broken backs, which are spoken of as causative of paraplegia, are not broken at all, but the ligaments are badly sprained.  The same condition exists here as in other sprained joints.  There may be marked kyphosis, but this does not necessarily indicate dislocation.  The paraplegic condition may be perpetuated by the pressure of connective tissue formed in the repair of the injury.  This is especially liable to follow if some form of manipulative treatment is not persisted in for from one to three years.  The author has fortunately been able to observe the slow regeneration of nerve tissue following complete paraplegia as a result of injury of the dorso-lumbar articulation.  This case has been observed by us during nearly four years.  During all of this time, she has received osteopathic treatment.  This method of treatment was not begun until ten months after the accident, therefore, synovial adhesions had formed to such all extent in the joints of the limbs that much painful manipulation of these joints has been necessary.

    Following the accident, there was motor and sensory paralysis of the extremities, bladder and rectum.  Control of the bladder and rectum returned after two months of osteopathic treatment.  Sensation and motion have returned to the extremities.  There is deformity as a result of the adhesions formed during the ten months previous to the first osteopathic manipulation.  The patient had been massaged during the ten months mentioned.

    Lumbar and Sacral Plexuses. - From the nerves of the cauda equina are formed two large plexuses, the lumbar and sacral, indicated in Fig. 53.  The branches of these plexuses innervate the muscles of the lower extremities.  The spinal area from which these plexuses receive their fibers should be carefully examined whenever any difficulty of movement or sensation in, the lower extremities is presented.

    The student should learn the sensory and motor distribution of each branch of these plexuses, so that peripheral disturbance call be immediately associated with the point of emergence from the spinal column of the affected nerve or nerves.

    The Bladder. - Fig. 54 indicates the superficial area in which reflexes from the bladder are most frequently found.  The sensory fibers to the bladder are found in the first, second, third and fourth sacral nerves.  The first to third give the strongest evidence of sensory disturbance.  When the mucous lining of the bladder is congested, these sensory nerves are stimulated.  Motor fibers to the bladder are found in the second and third sacral nerves, The stimulation of the sensory nerves results in reflex stimulation of the motor nerves, which cause contraction of the muscular tissue of the bladder.

    Inflammation of the bladder is accompanied by almost continuous desire to micturate.

    The sacral spinal nerves take a more direct and uninterrupted course to the pelvic viscera than do nerves from other portions of the spinal column to their respective areas of distribution.

    Inhibitory pressure over the sacral foramina has a very marked effect on the sensory nerves of the bladder.  This pressure does not directly affect the anterior divisions of the sacral nerves, nevertheless the effect is the same as though the anterior divisions were subjected to the inhibitory pressure.  This is evidence of the close harmony between the two divisions of a spinal nerve.  The inhibitory pressure not only lessens conscious pain in the bladder, but also changes the vasomotor conditions. In this respect it much resembles the action of heat applied to the surface.

    Sphincter Vaginae. - The sphincters of the vagina and rectum are controlled from the area of the third and fourth sacral nerves.  When the vulva, vagina or rectum are highly sensitive, we usually find a hyper aesthetic area at the third and fourth sacral spines.  When this area is sensitive, the point where the pudic nerve crosses the ischiatic spine is also decidedly sensitive to pressure.  Fig. 56 indicates the superficial relation of the pudic nerve.  This nerve is sensory and motor to the skin and muscles of the perineum.  This point will be found sensitive when the prostate is enlarged; in fact, almost any disorder of the male sexual organism is accompanied by this sensitive condition.

    Inhibitory movements over the back of the sacrum and ischiatic spine will result in relaxation of the perineal muscles.  It affects spasmodic stricture of the urethra in a wonderful manner.  The local anaesthetic effect of inhibition is not so easily demonstrated in any other portion of the body as in this sacral area.

    When the uterus is turned either backward or forward or prolapsed, there are impulses aroused in sensory nerve fibers in the rectum or bladder.  These impulses are reflexed to the sacral area, while those aroused in the uterus pass to higher points in the spinal column.  Inhibition of this sacral area will have a temporary effect.  The only treatment worth while is the correcting of the position of the uterus.

    Conclusions. - There are many more so-called "centers" mentioned by osteopathic writers.  We have not attempted to even recapitulate those other centers which seem to us to be quite too fanciful for practical use.  The centers mentioned in this chapter are those which can be demonstrated in daily practice, and hence are used continually, both as guides for diagnosis and as indications for the application of manipulative therapeutics.  No sympathetic spinal centers for "sensation," "motion" or nutrition" can be demonstrated.  These are characteristics of nerve fibers in general, and it is entirely misleading to limit these characteristics to any one portion of the spinal column.  Every osteopathic center should be capable of demonstration anatomically, physiologically and clinically.  Only those which can pass this test satisfactorily are worthy of our consideration.