Bodily Changes in Pain, Hunger, Fear and Rage

Other digestive glands than the salivary and the gastric may be checked ia emotional excite- ment. Eecently Oechsler^ has reported that in such psychic disturbances as were shown by Bickel and Sasaki to be accompanied by sup- pressed secretion of the gastric juice, the secre- tion of pancreatic juice may be stopped, and the | flow of bile definitely checked. All the means of bringing about chemical changes in the food may be thus temporarily abolished.

Emotions Favorable and Unfavorable to the Contractions OP THE Stomach and Intestines The secretions of' the digestive glands and the chemical changes wrought by them are of little worth unless the food is carried onward through the alimentary canal into fresh regions of diges- tion and is thoroughly exposed to the intestinal wall for absorption. In studying these mechani- cal aspects of digestion I was led to infer ^^ that (^just as there is a psychic secretion, so likei wise there is probably a "psychic tone" or "psy-l chic contraction" of the gastro-intestinal musclesl as a result of taking food. For if the vagus nerve supply to the stomach is cut immediately before an animal takes food, the usual contractions of y the gastric wall, as seen by the Eontgen rays, dc not occur; but if these nerves are cut after fooc has been eaten with relish, the contractions which

have started continue without cessation?^ The nerves in both conditions were severed under anesthesia, so that no element of pain entered into the experiments. In the absence of hunger, which in itself provides a contracted stomach,^^ the pleasurable taking of food may, therefore, be a primary condition for the appearance of natural contractions of the gastro-intestinal canal. Again just as the secretory activities of the stomach are unfavorably influenced by strong emotions, so also are the movements of the stom- ach; and, indeed, the movements of almost the entire alimentary canal are wholly stopped dur- ing great excitement. In my earliest observa- tions on the movements of the stomach ^^ I had difficulty because in some animals the waves of contraction were perfectly evident, while in others there was no sign of activity. Several weeks passed before I discovered that this difference was associated with a difference of sex. In order to be observed with Eontgen rays the animals were restrained in a holder. Although the holder was comfortable, the male cats, particularly the young males, were restive and excited on being fastened to it, and under these circumstances gastric peristaltic waves were absent; the female cats, especially if elderly, usually submitted with calmness to the restraint, and in them the waves had their normal occurrence. Once a female with

kittens turned from her state of quiet content- ment to one of apparent restless anxiety. The movements of the stomach immediately stopped, the gastric wall became wholly relaxed, and only after the animal had been petted and began to purr did the moving waves start again on their course, (^y covering the cat's mouth and nose\ with the fingers until a slight distress of breath- 1 ing is produced, the stomach contractions can be j stopped at willT^ In the cat, therefoje, anv sign[ilh of^ rage or fear, such as was seen in dogs by Le / Conte and by Bickel and Sasaki(was accompanied! J by a total abolition of the movements of the! stomach.y Even indications of slight anxiety may be attended by complete absence of the churning waves. In a vigorous young male cat I have watched the stomach for more than an hour by means of the Eontgen rays, and during that time not the .slightest beginning of peristaltic activity appeared; yet the only visible indication of ex- citement in the animal was a continued quick twitching of the tail to and fro. What is true of the cat I have found true also of the rabbit, dog and guinea-pig ^* — ^very mild emotional dis- turbances are attended by abolition of peristalsis. The observations on the rabbit have been con- firmed by Auer,^* who found that the handling of the animal incidental to fastening it gently to a holder stopped gastric peristalsis for a

variable length of time. And if the animal was startled for any reason, or struggled excitedly, peristalsis was again abolished. The observa- tions on the dog also have been confirmed; Lom- meP^ found that small dogs in strange sur- roundings might have no contractions of the stomach for two or three hours. And whenever the animals showed any indications of being un- comfortable or distressed, the contractions were inhibited and the discharge of contents from the stomach checked.

There is no doubt that just as the secretory activity of the stomach is affected in a similar fashion in man and in lower animals, so likewise gastric and intestinal peristaltic waves are stopped in man as they are stopped in lower ani- mals, by worry and anxiety and the stronger f affective states. (^ The conditions of mental discord \ may thus give rise to a sense of gastric inertia. For example, a patient described by Miiller ^^ testified that anxiety was always accompanied by a feeling of weight, as if the food remained in the stomach. Every addition of food caused an

increase of the trouble. Strong emotional states in this instance led almost always to gastric dis- tress, which persisted, according to the grade and the duration of the psychic disturbance, between a half-hour and several days. The patient was not hysterical or neurasthenic, but was a very sensitive woman deeply affected by moods. The feeling of heaviness in the stomach, men-| tioned in the foregoing case, is not uncommonlj complained of by nervous persons, and may be due to stagnation of the contents. That sue! stagnation occurs is shown by the following in- stance. A refined and sensitive woman, who had had digestive difficulties, came with her husband to Boston to be examined. They went to a hotel for the night. The next morning the woman ap- peared at the consultant's office an hour after having eaten a test meal. An examination of the gastric contents revealed no free acid, no diges- tion of the test breakfast, and the presence of a considerable amount of the supper of the pre- vious evening. The explanation of this stagna- tion of the food in the stomach came from the family doctor, who reported that the husband had made the visit to the city an occasion for be- coming uncontrollably drunk, and that he had by his escapades given his wife a night of turbu- lent anxiety. The second morning, after the woman had had a good rest, the gastric eon-

tents were again examined; the proper acidity was found, and the test breakfast had been nor- mally digested and discharged. These cases are merely illustrative and doubt- less can be many times duplicated in the experi- ence of any physician concerned largely with di- gestive disorders., -^Indeed, the opinion has been expressed that a great majority of the cases of gastric indigestion that come for treatment are functional in character and of nervous origin. It is the emotional element that seems most char- acteristic of these cases.^To so great an extent is this true that Rosenbach has suggested that as a term to characterize the cause of the distur- bances, Q"emotional" dyspepsia is better than "nervous" dyspepsia.^'^

The advocates of the theory of organic evolu- tion early pointed out the similarity between the bodily disturbances in pain and in the major emo- tions. The alterations of function of internal or- gans they could not know about. The general statement, however, that pain evokes the same changes that are evoked by emotion, is true also M these deep-lying structures. Wertheimer^^ proved many years since that stimulation of a I sensory nerve in an anesthetized animal — such Istimulation as in a conscious animal would in-

duce pain — quickly abolished the contractions of the stomach. And Netschaiev, working in Paw- low's ^® laboratory, showed that excitation of the sensory fibres in the sciatic nerve for two or three minutes resulted ia an inhibition of the secretion of gastric juice that lasted for several hours. Similar effects from painful experience have been not uncommonly noted in human be- ings. Mantegazzaj^"* in his account of the physi- ology of pain, has cited a number of such ex- amples, and from them he has concluded tha1(pain^ > interferes with digestion by lessening appetite and by producing various forms of dyspepsia, with arrest of gastric digestion, and with vomit- ing and diarrhea.^ The expression, "sickening, pain" is testimony to the power of strong sensory stimulation to upset the digestive processes pro- foundly. Vomiting is as likely to follow violent pain as it is to follow strong emotion. A "sick headache" may be, indeed, a sequence of events in which the pain from the headache is primary, and the nausea and other evidences of digestive disorder are secondary.

As the foregoing account has shown, emotional conditions or "feelings" may be accompanied by quite opposite effects in the alimentary canal, some highly favorable to good digestion, some highly disturbing. It is an interesting fact that the feelings having these antagonistic actions are typically expressed through nerve supplies which are correspondingly opposed in their influence on the digestive organs. The antagonism between these nerve supplies is of fundamental impor- tance in understanding not only the operation of conditions favorable or unfavorable to digestion but also in obtaining insight into the conflicts of emotional states. Since a consideration of the arrangement and mode of action of these nerves will establish a firm basis for later analysis and conclusions, they will next be considered.

^ Bidder and Schmidt : Die Verdauungssafte und der StofFwechsel, Leipzig, 1852, p. 35. * Bickel : Berliner klinische Wochensohrift, 1906, xliii, p. ° Oechsler : Internationelle Beitrage zur Pathologie und Therapie der Ernahrungstorungen, 1914, v, p. 1. The structures of the alimentary canal which are brought into activity during the satisfactions of appetite or are checked in their activity during pain and emotional excitement are either the se- creting digestive glands or the smooth muscle which surrounds the canal. Both the gland cells and the smooth-muscle cells differ from other tells which are subject to nervous influence — those of striated, or skeletal, muscle — in not being directly under voluntary control and in being slower in their response. The muscle connected with the skeleton responds to stimulation within two or three thousandths of a second; the delay with gland cells and with smooth muscle is more likely to be measured in seconds than in fractions of a second.

The Outlying Neurones The skeletal muscles receive their nerve supply direct from the central nervous system, i. e., the nerve fibres distributed to these muscles are parts of neurones whose cell bodies lie within the brain or spinal cord. The glands and smooth muscles! /^ of the viscera, on the contrary, are, so far as is ;: now known, never innervated directly from the central nervous system.* The neurones reaching! out from the brain or spinal cord never come into immediate relation with the gland or smooth- muscle cells ; there are always interposed between the cerebrospinal neurones and the viscera extra neurones whose bodies and processes lie wholly outside the central nervous system. They are represented in dotted lines in Fig. 1. I have sug- gested that possibly these outlying neurones act as "transformers," modifying the impulses re- ceived from the central source (impulses suited to call forth the quick responses of skeletal muscle), and adapting these impulses to the peculiar, more slowly-acting tissues, the secreting cells and vis- ceral muscle, to which they are distributed.^

The outlying neurones typically have their cell bodies grouped in ganglia (Gr's, Fig. 1) which, in the trunk region, lie along either side of the spinal cord and in the head region and in the pelvic part of the abdominal cavity are disposed near the organs which the neurones supply. In some instances these neurones lie wholly within the * The special case of the adrenal glands will be considered later. Figure 1. — Diagram of the more important distributions of the autonomic nervous system. The brain and spinal cord are repre- sented at the left. The nerves to skeletal muscles are not repre- sented. The preganglionic fibres of the autonomic system are in solid Unes, the postganglionic in dash-lines. The nerves of the cranial and sacral divisions are distinguished from those of the thoracioo-lumbar or "sympathetic," division by broader lines. A -|- mark indicates an augmenting effect on the activity of the organ; a — mark, a depressive or inhibitory effect. For further descrip- tion see text.

structure which they innervate (see e. g., the heart and the stomach, Fig. 1). In other instances the fibres passing out from the ganglia — the so-called "postganglionic fibres" — may traverse long dis- tances before reaching their destination. The in- nervation of blood vessels in the foot by neurones whose cell bodies are in the lower trunk region is an example of this extensive distribution of the fibres. As suggested above, the outlying neurones are connected with the brain and spinal cord by neurones. whose cell bodies lie within the central nervous organs. These connecting neurones, rep- resented in continuous lines in Fig. 1, do not pass out in a continuous series all along the cerebro- spinal axis. Where the nerves pass out from the spinal cord to the fore and hind limbs, fibres are not given off to the ganglia. Thus these connect- ing or "preganglionic" fibres are separated into three divisions. In front of the nerve roots for the fore limbs is the head or cranial division, be- tween the nerve roots for the fore limbs and those for the hind limbs is the trunk division (or thorad- ico-lumbar division, or, in the older terminology, the "sympathetic system"); and after the nerve roots for the hind limbs the sacral division.

ganglionic fibres innervating the viscera, and with preganglionic fibres reaching out to them from the cerebrospinal system, has been called by Langley, to whom we are indebted for most of our knowledge of its organization, the autonomic nervous system.^ This term indicates that the structures which the system supplies are not sub- ject to voluntary control, but operate to a large degree independently. As we have seen, a highly potent mode of influencing these structures is through conditions of pain and emotional excite- ment. The parts of the autonomic system — the cranial, the sympathetic, and the sacral— have a number of peculiarities which are of prime im- portance in accounting for the bodily manifesta- tions of such affective states.

The Extensive Distribution of Neurones of the "Sympa- thetic" Division and Their Arrangement for Diffuse Action /The fibres of the sympathetic divisioiJ^differ from those of the other two divisions inybeing /aistributed through the body very widely. They go to the eyes, ^causing dilation of the pupils. They go to the heart and, when stimulated, they cause it to beat rapidly. They carry impulses to arteries and arterioles of the skin, the abdominal viscera, and other parts, keeping the smooth mus- cles of the vessel walls in a state of slight con-

traction or tone, and thus serving to maintain an arterial pressure sufficiently higli to meet sud- den demands in any special region; or, in times of special discharge of impulses, to increase the tone and thus also the arterial pressure. They are distributed extensively to the smooth muscle attached to the hairs; and when they cause this muscle to contract, the hairs are erected. They go to sweat glands, causing the outpouring of sweat. These fibres pass also to the entire length of the gastro-intestinal canal. And the inhibi- ^ion of diges^ve activity which, ^ as . we have learned, occurs in pain and emotional states, i_s due to impulses which are conducted outward by the splanchnic nerves — the preganglionic fibres that reach to the great ganglia in the upper abdo- men (see Fig. 1) — and thence are spread by post- ganglionic fibres all along the gut.* They in- nervate likewise the genito-urinary tracts, causing contraction of the smooth muscle of the internal genital organs, and usually relaxation of the blad- der. Finally they affect the liver, releasing the storage of material there in a manner which may be of great service to the body in tiine of need. The extensiveness of the distribution of the fibres of the sympathetic division is one of its most prominent characteristics.

Another typical feature of the sympathetic di- vision is an arrangement of neurones for diffuse discharge of tlie nerve impulses. As shown dia- grammatically in Fig. 1, the preganglionic fibres from the central nervous system may extend through several of the sympathetic ganglia and give off in each of them connections to cell bodies of the outlying neurones. Although the neurones which transmit sensory impulses from the skin into spinal cord have similar relations to nerve cells lying at ditferent levels of the cord, the op- eration in the two cases is quite different. In the spinal cord the sensory impulse produces di- rected and closely limited effects, as, for example, when reflexes are being evoked in a "spinal" ani- mal (i. e., an animal with the spinal cord isolated from the rest of the central nervous system), the left hind limb is nicely lifted, in response to a harmful stimulus applied to the left foot, without widespread marked involvement of the rest of the body in the response.* In the action of the sympathetic division, on the contrary, the con- nection of single preganglionic fibres with nu- merous outlying neurones seems to be not at all arranged for specific effects in this or that par- ticular region. There are, to be sure, in different circumstances variations in the degree of ac- tivity of different parts; for example, it is prob- able that dilation of the pupil in the cat occurs more readily than erection of the hairs. It may be in this instance, however, that specially direct

pathways to the eye are present for common use in non-emotional states (in dim light, e. g.), and that only slight general disturbance in the central nervous system, therefore, would be necessary to send impulses by these well-worn courses. Thus for local reasons (dust, e. g.) tears might flow from excitation of the tear glands by sympathetic impulses, although other parts innervated by this same division might be but little disturbed. We have no means of voluntarily wearing these path- ways, however, and^both from anatomical and physiological evidence^ the neurone relations in the sympathetic division of the autonomic system seem devised for widespread diffusion of nervous impulses.

The Arrangement of Neurones of the Cranial and Sacral Divisions for Specific Action The cranial and sacral autonomic divisions differ from the sympathetic in having only re- stricted distribution (see Fig. 1). The third cran- ial nerves deliver impulses from the brain to ganglia in which lie the cell bodies of neurones innervating smooth muscle only in the front of the eyes. The vagus nerves are distributed to the lungs, heart, stomach, and small intestine. As shown diagrammatically in Fig. 1, the out- lying neurones in the last three of these organs lie within the organs themselves. By this ar- rangement, although the preganglionic fibres of

the vagi are extended in various directions to structures of quite diverse functions, singleness and separateness of connection of the peripheral organs with the central nervous system is as- sured. The same specific relation between effer- ent fibres and the viscera is seen in the sacral autonomic. In this division the preganglionic fibres pass out from the spinal cord to ganglia lying in close proximity to the distal colon, the bladder, and the external genitals. And the post- ganglionic fibres deliver the nerve impulses only to the nearby organs. Besides these innervations the cranial and sacral divisions supply individual arteries with "dilator nerves" — nerves causing relaxation of the particular vessels. Quite typi- cally, therefore, the efferent fibres of the two terminal divisions of the autonomic differ from those of the mid-division in having few of the distributed connections characteristic of the mid- division, and m. innervating distinctively the or- gans to which they are distributed. The cranial and sacral preganglionic fibres resemble thus the nerves to skeletal muscles, and their arrangement provides similar possibilities of specific and sepa- rate action in any part, without action in other parts.

system concerned in the psychic secretion of the gastric juice. Pawlow showed that when these nerves are severed psychic secretion is abolished. The cranial nerves to the salivary glands are sim- ilarly the agents for psychic secretion in these organs, and are known to cause also dilation of the arteries supplying the glands, so that during ac- tivity the glands receive a more abundant flow of blood. As previously stated (see p. 13), the evi- dence for a psychic tonus of the gastro-intestinal musculature rests on a failure of the normal con- tractions if the vagi are severed before food is taken, in contrast to the continuance of the con- tractions if the nerves are severed just after- wards. The vagi artificially excited are well- known as stimulators of increased tone in the smooth muscle of the alimentary canal. Aside from these positive effects on the muscles of the digestive tract and its accessory glands, cranial autonomic fibres cause contraction of the pupH of the eye, and slowing of the heart rate.

A glance at these various functions of the cra^ nial division reveals at once that they serve foi bodily conservation. By narrowing the pupil oi the eye they shield the retina from excessiv light. By slowing the heart rate, they give th cardiac muscle longer periods for rest and in'- vigoration. And by providing for the flow ol saliva and gastric juice and by supplying the mus I Sacral autonomic fibres cause contraction of the ' rectum and distal colon and also contraction of '' the bladder. In both instances the effects result reflexly from stretching of the tonically con- tracted viscera by their accumulating contents. No affective states precede this normal action of the sacral division and even those which accom- pany or follow are only mildly positive ; a feeling of relief rather than of elation usually attends the completion of the act of defecation or mic- turition— though there is testimony to the con- trary.

I The sacral autonomic fibres also include, how- lever, the nervi erigentes which bring about en- gorgement of erectile tissue in the external geni- Jtals. According to Langley and Anderson^ the sacral nerves have no effect on the internal gen- erative organs. The vasa deferentia and the seminal vesicles whose rhythmic contractions mark the acme of sexual excitement in the male, and the uterus whose contractions in the female are probably analogous, are supplied only by lumbar branches — part of the sympathetic divi- sion. These branches also act in opposition to the nervi erigentes and cause constriction of the blood vessels of the external- genitals. The sexual orgasm involves a high degree of emotional ex- citement; but it can be rightly considered as es- sentially a reflex mechanism; and, again in this instance, distention of tubules, vesicles, and blood vessels can be found at the beginning of the in- cident, and relief from this distension at the end. Although distention is the commonest occasion for bringing the sacral division into activity it is not the only occasion. Great emotion, such as is accompanied by nervous discharges via the sym- pathetic division, may also be accompanied by dis- charges via the sacral fibres. The involuntary voiding of the bladder and lower gut at times of violent mental stress is well-known. Veterans of wars testify that just before the beginning of a battle many of the men have to retire temporarily from the firing line. And the power of sights and smells and libidinous thouglits to disturb the regions controlled by the nervi erigentes proves that this part of the autonomic system also has its peculiar affective states. The fact that one part of the sacral division, e. g., the distribu-

tion to the bladder, may be in abeyance, while another part, e. g., the distribution to the rectum, is active, illustrates again the directive discharge of impulses which has been previously described as characteristic of the cranial and sacral portions of the autonomic system. Like the cranial division, the sacral is engaged in internal service to the body, in the performance of acts leading immediately to greater comfort. The Sympathetic DnasioN Antagonistic to Both the Cranial and the Sacral

As indicated in the foregoing description many of the viscera are innervated both by the cranial or sacral part of the autonomic and by the sym- pathetic. When the mid-part meets either end- part in any viscus their effects are antagonistic. Thus the cranial supply to the eye contracts the pupil, the sympathetic dilates it; the cranial slows the heart, the sympathetic accelerates it; the sacral contracts the lower part of the large intestine, the sympathetic relaxes it; the sacral relaxes the exit from the bladder, the sym- pathetic contracts it.N These opposed effects are indicated in Fig. i by 4- for contraction, ac- celeration or increased tone; and by - for inhibi- tion, relaxation, or decreased tone.*

* The vagus nerve, when artificially stimulated, has a pri- mary, brief inhibitory effect on the stomach and small intes- tine ; its main function, however, as already stated, is to pro- Sherrington lias demonstrated that the setting of skeletal muscles in opposed groups about a joint or system of joints — as in flexors and ex- tensors— is associated with an internal organiza- tion of the central nervous system that provides for relaxation of one group of the opposed mus- cles when the other group is made to contract. This "reciprocal innervation of antagonistic mus- cles," as Sherrington has called it,** is thus a device for orderly action in the body. As the above description has shown, there are peripheral oppositions in the viscera corresponding to the oppositions between flexor and extensor muscles. In all probability these opposed innervations of the viscera have counterparts in the organization of neurones in the central nervous system. Sher4 rington has noticed, and I can confirm the obser-i vation, that even though the sympathetic supplv to the eye is severed and is therefore incapable on causing dilation of the pupil, nevertheless the pupil dilates in a paroxysm of anger — due, no doubt (because the response is too rapid to be mediated by the blood stream), to central inhibi- tion of the cranial nerve supply to the constrictor muscles — i. e., an inhibition of the muscles which naturally oppose the dilator action of the sym- pathetic. Pain, the major emotions — fear and

duce increased tone and contraction in these organs. This double action of the vagus is marked thus, q: , in Fig. 1. I rage — and also intense excitement, are manifested ^ in the activities of the sympathetic division. When in these states impulses rush out over the neurones of this division they produce all the changes typical of sympathetic excitation, such las dilating the pupils, inhibitmg digestion, caus- I ing pallor, accelerating the heart, and various ' other well-known effects. The impulses of the sympathetic neurones, as indicated by their domi- nance over the digestive process, are capable of readily overwhelming the conditions established by neurones of the cranial division of the auto- nomic system.

Neurones of the Sympathetic Division and Adrenal Secretion Have the Same Action Lying anterior to each kidney is a small body — the adrenal gland. It is composed of an external portion or cortex, and a central portion or me- dulla. From the medulla can be extracted a sub- stance, called variously suprarenin, adrenin, epi- nephrin. or "adrenalin,"* which, in extraordinarily minute amounts, affects the structures innervated by the sympathetic division of the autonomic sys-