224 ANATOMY AND PHYSIOLOGY FOR NURSES 



glia. It is distributed to the vocal cords, lungs, pharynx, 

 esophagus, stomach, and heart. It gives off the following 

 branches: Meningeal, auricular, pharyngeal, superior 

 laryngeal, recurrent laryngeal, cervical cardiac, thoracic 

 cardiac, anterior pulmonary, posterior pulmonary, esoph- 

 ageal, gastric, and abdominal plexuses. (See Fig. 113.) 



The eleventh, or spinal accessory, is a motor nerve, 

 having its origin in the medulla oblongata, and making 

 its exit through the foramen magnum; it is distributed 

 to the muscles of the neck, pharynx, and palate, and is 

 said to be a constrictor nerve of the heart. 



The twelfth, or hypoglossal, is a motor nerve that sup- 

 plies the tongue. It arises from the floor of the fourth 

 ventricle, and makes its exit through the anterior condy- 

 loid foramen. It gives off the meningeal, muscular, and 

 vascular branches. It supplies the tongue and the in- 

 ternal muscles of the throat, and communicates with the 

 second and third cervical and sympathetic nerves. 



The Spinal nerves arise from the spinal cord. There 

 are 31 pairs of these nerves 8 cervical, 12 dorsal, 5 lum- 

 bar, 5 sacral, i coccygeal. The function of these nerves 

 has already been described. The following notes are 

 taken from the researches of Blandin. 1 He says, regarding 

 the relative size of the anterior and posterior roots of the 

 several regions of the spine: 



The posterior roots are to the anterior in the cervical region . . . . 2 : i 

 The posterior roots are to the anterior in the dorsal region . . . . i : i 

 The posterior roots are to the anterior in the lumbar and 



sacral regions I? : I 



This writer states further that this relation quite accords 

 with the great delicacy of the sense of touch in the upper 

 extremities. 



Each spinal nerve, as has been stated, arises by two 

 1 Anal, descript., 1838, t. ii., p. 648. 



