94 PSYCHOBIOLOGY 



muscles of the pharynx and the base of the tongue, and to the parotid 

 gland (secretory). From the vagus (including the bulbar accessory) 

 efferent fibers are distributed to the muscles of the larynx ; the three con- 

 strictors of the pharynx; the levator palati; the heart (inhibitory) ; the 

 muscular walls of the esophagus, stomach, and small intestine ; the muscle 

 in the walls of the bronchi and bronchioles; and to the glands of the 

 stomach and possibly to the pancreas. 



The fibers of the spinal accessory nerve are distributed to the sterno- 

 mastoid and trapezius muscles. 



The afferent fibers of the ninth nerve are distributed peripherally to 

 the tongue, mouth, and pharynx. The afferent fibers of the tenth nerve 

 supply the meninges ; the pinna and external auditory meatus ; the mucous 

 membrane of the pharynx, larynx, and posterior part of the tongue; and 

 the mucous membrane of the trachea, bronchi, and pulmonary alveoli. 

 Possibly all tissues to which efferent fibers of the vagus extend are also 

 supplied with vagal afferent fibers, but this is not demonstrated, certainly 

 the principal afferent supply of the viscera is from the sympathetic. 



XII. The hypoglossal nerve (efferent only), arises from a nucleus 

 in the floor of the fourth ventricle, beginning at the level of the striae 

 acusticae and extending downward about the length of the olive. These 

 fibers are distributed to all the muscles of the tongue except the palato- 

 glossal and pharyngo-glossal, and to the extrinsic muscles of the larynx. 

 Fibers of the first three cervical spinal nerves also join the twelfth nerve 

 and are distributed through it to the thyro-hyoid and genio-hyoid muscles. 



REFERENCES ON GROSS RELATIONS OF NERVE, CORD, BRAIN, AND GANGLIA. 



Starling, Physiology, Ch. VII, §§ VI, X, XI, XV and XVIII. 



Cunningham, Anatomy, § The Nervous System. 



Villiger, The Brain and Spinal Cord (Piersol's Translation). 



Schafer, Quoin's Anatomy, Vol. Ill, Pt. I (General Neurology and the Central 



Nervous System). 

 Howell, Physiology, Chs. VIII-XI. 



Lewis and Stohr, Histology, § III, Sub-§ The Central Nervous System. 

 Luciani, Human Physiology, Vol. Ill, Chapters V-X. 

 Herrick, An Introduction to Neurology, Chapters VII-XV. 



