NEUROLOGY. 131 



*'*'*, posterior nasal nerves; ', palatine nerves; '', lingual nerve and chorda 

 tympani ; *, submaxillary nerve ; ", superficial temporal nerve ; '°, inner 

 pterygoid ; ", ganglion oticum ; ''\ threads from it to the tympanum, and to the 

 mucous membrane of the nose ; ", connecting branch to the focial nerves ; ", 

 threads to the tensor t3nnpani ; ", threads to the plexus, along the internal, 

 maxillary artery ; ", facial nerve ; ", chorda tympani. 



PI. 188, fig. 11, nerves of the larynx: ', superior, °, inferior laryngeal 

 nerves; ', union of the two. Fig. 12 ', laryngeal; '', thyroid gland; ', tra- 

 chea ; ", arteria innominata ; '', right lung ; ", stomach ; \ great coeliac 

 plexus; °' \ glosso-pharyngeal nerve; '", lingual branch of the fifth pair ; 

 ", hypoglossus ; '^, accessory nerve ; ", division into the muscular branch 

 and into the branch to the tenth pair ; ", vagus ; '", its pharyngeal branch 

 uniting with threads of the glosso-pharyngeus and sympatheticus to form 

 the pharj^ngeal plexus ; ", superior laryngeal nerve and its division into an 

 outer and an inner branch ; "'"»"^ nerves of the heart ; ", oflf-shoot of the 

 recurrens; ", inferior cervical plexus of the sympatheticus; ^°, tracheal 

 branch ; °', pulmonic plexus ; ", pharyngeal nerves ; ", entrance of the right 

 vagus into the coeliac plexus ; ", left trunk, and its distribution on the 

 stomach ; ^^, coeliac plexus. 



B. Spinal Nerves. 



There are thirtj^-one pairs of spinal nerves, each arising by two roots, an 

 anterior or motor root, and a posterior or sensitive root. 



The anterior roots proceed from a narrow white line, anterior lateral 

 sulcus, on the antero-lateral column of the spinal cord, and gradual!}" 

 approach towards the anterior longitudinal fissure as they ascend. The 

 posterior roots proceed from the posterior lateral sulcus, a narrow grey 

 stria, formed by the internal grey substance of the cord. 



After the formation of a ganglion the two roots unite and constitute a 

 spinal nerve. The spinal nerves are divided into cervical, dorsal, lumbar, 

 and sacral. The cervical nerves pass off transversely from the spinal 

 cord ; the dorsal are oblique in their direction, and the lumbar and sacral 

 vertical ; the latter form the large assemblage of nerves at the termination 

 of the cord called cauda equina. 



1. The Cervical Nerves are eight in number, increasing in size as they 

 descend; the first passes out above the atlas, and is named the sub- 

 occipital ; the eighth passes out above the first dorsal vertebra. All of 

 these, except the first and second, immediately outside the intervertebral 

 foramina, divide into a posterior and an anterior branch ; the posterior of 

 each is generally the smaller. The anterior branches of the first four form 

 the cervical plexus, and those of the last four with the first dorsal, the 

 brachial plexus. 



2. The Cervical Plexus is formed by the loops and conmiunications 

 between the anterior branches of the four superior cervical nerves, which 

 join each other in arches, from the convexities of which branches arise that 

 again join in a similar manner : lymphatic glands and a quantity of cellular 

 tissue are entangled in the areolaa between these. This plexus commu--, 



837 



