MEDULLA OBLONGATA 



5 2 3 



antero-median furrow below the decussation, and on one side 

 push in lateral direction the anterior funiculus of the medulla 

 spinalis. The pyramid will then be seen to divide into two 

 portions, viz., a small strand termed the fasciculus cerebro- 

 spinalis anterior (O.T. direct pyramidal tract\ which proceeds 

 downwards into the anterior funiculus of the spinal medulla 



N. H. Nucleus hypoglossi. 

 N. V. Vago-glosso-pharyngeal 



nucleus. 



F.S. Tractus solitarius. 

 N.A. Nucleus ambiguus. 



PYR.TR. 

 DIR.PYR.TR. 



FIG. 220. Diagram of the Decussation of the Pyramids. 

 (Modified from Van Gehuchten. ) 



close to the antero - median furrow, and a much larger 

 strand called the fasciculus cerebrospinalis later alis (O.T. 

 crossed pyramidal tract\ which, at this level, is broken up into 

 three or more coarse bundles which sink posteriorly and, at 

 the same time, cross the median plane to take up a position 

 in the opposite lateral funiculus of the spinal medulla, close 

 to the posterior column of grey matter. It is the inter- 

 crossing of the corresponding bundles of the fasciculi cerebro- 



