CARDIALGIA, BOULIMIA, POLYDIPSIA.

503

shoot down the arm or into the neck. The paroxysms produce the most rapid exhaustion, and are not usually long continued. The various pathological conditions found to exist in this affection include an ossified state of the coronary vessels (thus interfering with the nutrition of the heart walls); cardiac hypertrophy (which is usually of that form called compensatory, since the cavities of the heart are generally dilated); fatty degeneration of the heart; valvular lesions (with their secondary changes in the size of the cavities); and aneurism within the pericardial sac.

The gastric branches of the vagus are associated with the conditions of gastrodynia (cardialgia), boulimia, polydipsia, nervous vomiting, and disorders of the secretory follicles of the organ, as well as its power of absorption. Gastrodynia is a paroxysmal attack of neuralgia of the sensory fibers of the stomach. It produces pain of the most intense character, which often compels the strongest subjects to writhe in agony, and to become bathed in a profuse perspiration, irrespective of the temperature of the atmosphere. The face becomes bloodless, the limbs cold, the abdomen retracted, and the pulse small and irregular. The attacks are usually of short duration, and are most frequently terminated by eructations and vomiting. This disease is met with in hysterical and anæmic subjects, in the course of diseases of the uterus and ovaries, in spinal and cerebral affections, and in certain dyscrasiæ.

An abnormal condition of hunger, which is appeased by small quantities of food, but which returns at frequent interIvals with an uncontrollable desire, often interrupting the hours of sleep, is produced by some disordered condition of the vagus, and is called "boulimia." This affection is met with in hysterical patients, after prolonged fevers, in severe forms of nervous debility, in syphilis, insanity, and diabetes.

By "polydipsia" we mean an intolerable thirst, dependent upon an hyperæsthesia of the nerve fibers of the mucous membrane of the stomach, pharynx, and mouth, and prob

ably due to some abnormal state of the pneumogastric nerve. It is often an associate symptom with boulimia, and is produced by the same general causes.

The state of "polyphagia" signifies a desire for excessive quantities of food. It is supposed to exist when the nerve fibers of the vagus distributed to the stomach are in a state of anæsthesia, in contrast to the condition producing the two previous diseases. It has been found to accompany softening of the medulla oblongata, compression of the roots of the vagus by an aneurismal tumor of the vertebral artery, atrophy of the vagi, neuromata of the vagi, and the morbid states of epilepsy, insanity, and hysteria.

The nervous vomiting which is clinically observed in connection with pregnancy, chlorosis, hysteria, digestive disturbances, and gastrodynia, is not to be confounded with that of local diseases of the stomach or of the alimentary canal, since the symptom depends, purely and exclusively, upon some abnormal condition of the nerves, rather than upon pathological changes in the stomach or intestine.

True paralysis of the gastric branches of the vagus must, of necessity, arrest the peristaltic movement of that organ, and thus tend to favor the retention of food within its cavity. This may be the explanation of the enormous enlargement of the stomach found after chronic inflammatory processes of that organ, and also as a sequel to cholera, typhoid fever, and some other blood poisons. The stomach becomes enlarged in these conditions mainly by the weight of the retained food and the pressure of the gases formed by its decomposition.

The intestinal and hepatic branches of the vagus are not well understood in their clinical phenomena, but the effects of section of the pneumogastric seem to point to some controlling influence of these fibers over the glycogenic function of the liver and the secretion of the intestinal juices. The effect of diseases of the peritonæum, or of the abdominal viscera, upon the heart and respiration, is to be explained either as the direct result of irritation of these fibers, or as a

THE SPINAL ACCESSORY NERVE.

505

reflex act through the sympathetic nerve upon the cardiac and respiratory centers, thus in turn affecting the heart and lungs through the vagus.

THE SPINAL ACCESSORY, OR ELEVENTH CRANIAL NERVE.

This nerve has a very extensive origin, since it derives its fibers not only from the medulla oblongata, but also from the cervical portion of the spinal cord. The fibers which arise from the medulla compose what is called the "bulbar portion," in contrast to those which arise from the cervical region of the spinal cord, to which the name of "spinal portion" is sometimes given. Such a distinction has an importance, distinct from merely indicating the point of origin of the fibers composing the two portions of the nerve, as the functions of the two are different.

If we trace the filaments of origin of the bulbar portion of the nerve, we can perceive that the fibers arise from the lateral columns of the medulla oblongata (its motor tract) and escape from its lower portion, beneath the fibers of the pneumogastric nerve. The spinal portion of the nerve can be traced between the anterior and the posterior roots of the first five cervical nerves, arising from between the roots of each nerve by a pair of filaments, with the exception of the last two, where the filament going to form the spinal accessory nerve is usually a single one. These several fibers unite ast the nerve passes upward toward the cranium, thus causing the spinal portion of the nerve to gradually increase in size. In the cranium, the two parts join to form one nerve, which then escapes from the jugular foramen, in company with the pneumogastric and glosso-pharyngeal nerves and the jugular vein. The inferior meningeal artery enters the cavity of the cranium through this foramen, and therefore bears a relation to the nerves and vein.

The spinal accessory nerve receives filaments of communication with other nerves, even before it escapes from the cavity of the cranium, since the spinal portion, on its way

upward to unite with the bulbar portion, is joined by filaments derived from the two upper cervical nerves while in the spinal canal.

After the nerve has emerged from the jugular foramen, it gives off a large branch to the pneumogastric nerve, and occasionally receives a filament from the pneumogastric in return;

FIG. 143.-Spinal accessory nerve. (Hirschfeld.)

1, trunk of the facial nerve; 2, 2, glosso-pharyngeal nerve; 3, 3, pneumogastric; 4, 4, 4, trunk of the spinal accessory; 5, sublingual nerve; 6, superior cervical ganglion; 7, 7, anastomosis of the first two cervical nerves; 8, carotid branch of the sympathetic; 9, 10, 11, 12, 13, branches of the glosso-pharyngeal; 14, 15, branches of the facial; 16, otic ganglion; 17, auricular branch of the pneumogastric; 18, anastomosing branch from the spinal accessory to the pneumogastric; 19, anastomosis of the first pair of cervical nerves with the sublingual; 20, anastomosis of the spinal acccEsory with the second pair of cervical nerves; 21, pharyngeal plexus; 22, superior laryngeal nerve; 23, external laryngeal nerve; 24, middle cervical ganglion.

while, in its course down the neck, it receives filaments of communication from the second, third, and fourth cervical nerves, in case these nerves do not communicate with the spinal portion within the spinal canal.

After the nerve has sent its upper filament to the pneumo

DISTRIBUTION OF SPINAL ACCESSORY.

507

gastric, at the jugular foramen, it may usually be perceived to divide into two branches-an internal and an external; the former of which anastomoses directly with the trunk of the pneumogastric nerve, while the latter, called the "muscular branch," pierces the back part of the upper third of the sternomastoid muscle, and terminates on the anterior surface of the trapezius. The first, sometimes called the "anastomotic

FIG. 144.-Posterior view of the muscles of FIG. 145.-Lateral view of the muscles of the larynx. (Sappey.)

the larynx. (Sappey.)

FIG. 144.-1, posterior crico-arytenoid muscle; 2, 3, 4, different fasciculi of the arytenoid muscle; 5, aryteno-epiglottidean muscle.

FIG. 145.-1, body of the hyoid bone; 2, vertical section of the thyroid cartilage; 3, horizontal section of the thyroid cartilage turned downward to show the deep attachment of the crico-thyroid muscle; 4, facet of articulation of the small cornu of the thyroid cartilage with the cricoid cartilage; 5, facet on the cricoid cartilage; 6, superior attachment of the crico-thyroid muscle; 7, posterior crico-arytenoid muscle; 8, 10, arytenoid muscle; 9, thyro-arytenoid muscle; 11, aryteno-epiglottide an muscle; 12, middle thyro-hyoid ligament; 13, lateral thyro-hyoid ligament.

branch," is now known to be the nerve which supplies the muscles of the larynx, with the exception of the crico-thyroid muscle,' since physiological experiment confirms this distribution.

1 The arytenoid muscle of the larynx is supplied by both the superior and recurrent laryngeal nerves, the latter of which carry most of the spinal accessory fibers, as is shown in Fig. 140 of this volume. It is also important to remember that the investiga