9 o 



THE NERVOUS SYSTEM 



definite groups. They are concerned with the reception and distribution of 

 the impulses entering along the fibers of the dorsal roots. 



Si 



S4- 



Fig. 65. Outline sketches of ventral horn of left side of cord at different levels, showing the 

 relative number and position of the chief cell-groups: C\, C\, T 6 , etc., indicate the segments e. g., 

 first cervical, fourth cervical, sixth thoracic; C (b), lower part of eighth cervical. The following 

 letters designate the cell-groups: v-m, Anteromedian; d-nt, posteromedian ; v-l, anterolateral ; 

 d-l, posterolateral ; p. d-l, retroposterolateral; v in LV, L*, ventral; c in L%, L 4 , S\, central; /. c. in 

 T 6 , Ti2, intermediolateral ; ace. in C\, C 4 , accessorius; phr. in C 4 , phrenic; Cl.c. in T 6 , Tu, nucleus 

 dorsalis. (Bruce, Quain's Anatomy.) 



The nucleus dorsalis, or column of Clarke, is a group of large cells in the 

 medial part of the base of the posterior column. It extends from the last cer- 



