5(3S 



THE SPIXAL NERVES. 



^-s. Fig. 351. 



"^: 



yf^'' 



<^t 



-vt^' 



/ X 



Fig. 351. — Diagrammatic OrTLiNE of the Roots 

 AND First Part of the Spinal Nerves, to- 

 gether WITH the Sympathetic Trunk of one 

 side. (A. T.) i 



The view is taken from Lefore. In tlie upper 

 part of the figure the i)ons Varolii and inediilla 

 oblongata are represented, and from V to IX, 

 the roots of the several cranial nerves from the 

 trifacial to the lij'poglossal are indicated. On 

 the left side C 1 is placed opposite the first cer- 

 vical or suboccijiital nerve ; and the numbers 2 to 

 8 following below indicate the corresponding cer- 

 vical nerves ; Br, indicates the brachial plexus ; 

 D 1, is placed opposite the intercostal part of the 

 first dorsal nerve, and the numbers 2 to 12 follow- 

 ing mark the corresponding dorsal nerves ; L 1, 

 the first lumbar nerve, and the numbers 2 to 5, 

 following the remaining lumbar nerves ; Cr, the 

 anterior crural, and o, the obturator nerve ; S 1, 

 the first sacral, and the following numbers 2 to 5, 

 the reniaining sacral nerves ; 6, the coccygeal 

 nerve ; Sc, the great sciatic nerve ; + , + , the 

 filum terminale of the cord. 



On tlie right side of the figure the following 

 letters indicate parts of the sympathetic nerves ; 

 viz., a, the superior cervical ganglion communi- 

 cating with the upper cervical spinal nerves and 

 continued below in the great sympathetic cord ; 

 b, the middle cervical ganglion ; c, d, the 

 lower cervical ganglion united with the first 

 dorsal ; d', the eleventh dorsal ganglion ; from 

 the fifth to the ninth dorsal ganglion the origins 

 of the great splanchnic nerve are shown ; I, the 

 lowest dorsal or upper lumbar ganglion ; ss, the 

 upper sacral ganglion. In the whole extent of the 

 sympathetic cord, the twigs of union with the 

 spinal nerves are shown. 



Summary. — The hypoglossal nerve 

 supplies, eitlier alone or in union with 

 branches of the spinal nerves, all the 

 muscles connected with the os hyoides, 

 including tliose of the tongue, with the 

 exception of the digastric, stylo-hyoid, 

 mylo-hyoid and the middle constrictor 

 of the pharyn.\-. It also supplies the 

 sterno- thyroid muscle. 



It is connected with the following 

 nerves, viz., pneumo-gastric, lingual, 

 three upper cervical nerves, and the 

 sympathetic. 



B. SPINAL NERVES. 



The spinal nerves are characterised 

 by their origin from the spinal cord, 

 and their direct transmission outwards 

 from the spinal canal in the intervals 

 between the vertebra. Taken together, 

 these nerves consist of thirty-one pairs ; 



sc 



