THE SPINAL MEDULLA 



} ffi- [(y-Vzr Internal capsule, motor fibres 



O ij ^-*^_ ] 



Nucleus of 3rd nerve 

 -Motor fibres in mid-brain 



\- Nucleus of yth nerve 

 .?~^? Motor fibres in pons 



Nucleus ot i2th nerve 

 'Decussation of fillet 



Motor fibres in medulla oblongata 



1 Decussation of pyramids 

 Fibres of muscle and joint sense 

 .ascending in posterior column 



j_\_Lateral cerebro-spinal tract 

 (crossed pyramidal) 



^Anterior cerebro-spinal tract 



"(direct pyramidal) 



Afferent fibres conveying muscle 

 -and joint sense 



-Spinal ganglion 



Fibres containing painful th 

 ind tactile stimuli 



ermal 



and tactile st 



FIG. 163. Diagrammatic Representation of the Chief Motor and Sensory 

 Tracts in the Central Nervous System. (After Purves Stewart.) The 

 black lines indicate the paths of the sensory fibres and the dotted lines 

 indicate the paths of the motor fibres. 



