Fig. 141. — Diagram of the Afferent and Efferent Paths passivg to and 

 from the Brain by the Cord (Sherrington). 



V, Left ; r, right ; cbm, cerebrum ; cbm, cerebellum ; vio, medulla oblongata, containing the decussa- 

 tion of /, the pyramidal tract, and of /, the fillet ; the decussation of / should really be a little higher 

 J instead of a little lower than that of p ; no, nucleus gracilis (Goll's) ; or, optic thalamus ; pvc, the superior 

 vesicular column, or column of Clarke; sp g, spinal ganglion; cg, median superior column (Coil's) : 

 dc y direct cerebellar tract. 



The arrows show the direction of the impulses. An afferent impulse, say from the skin, passes along 

 the sensory nerve, through the spinal ganglion, and enters the dorsal columns of the cord ; it may pass 

 to the cerebrum direct via the medulla by cg, the median superior column, which crosses in the bulb, 

 and so gains the opposite side of the brain ; or the impulse may pass by dc, the cerebellar tract, to the 

 cerebellum, entering it on the same side, and from here crossing over to the opposite cerebral hemisphere. 

 An efferent impulse originates in the cerebral cortex, gains the pyramidal tract, passes through the bulb 

 to the opposite side of the cord, enters the cells in the inferior cornu of the grey matter, and passes out 

 in the inferior spinal nerves. The arrows denote the direction of the impulses. 



