LEMNISCUS MEDIALIS 



495 



oblongata the medial lemniscus consists of fibres which have 

 ascended from the lateral and the anterior funiculi of the 

 spinal medulla, where they form tracts called the lateral and 

 the anterior spino-thalamic fasciculi. In the upper part of 

 the medulla oblongata the spino-thalamic fasciculi are joined 



Median ra 

 Cerebral peduncle 

 Upper border 



Oculo-motor nerve 



| Cerebro-pontine fibres ending in pons 

 ; Others are seen passing; to pyramid of 

 s^^^^,'i medulla oblongata 



Trigeminal nerve 



Glossopharyngeal 

 nerve 



s- / Flocculus 

 4 



Vagus nerve / t 

 Accessory nerve / 

 Olive 



Accessory nerve / 



Lemniscus 

 Pyramidal fibres (cut) Pyramidal decuss 



FIG. 199. Dissection of Pons and Medulla Oblongata to show Pyramidal 

 Fibres and Lemniscus. 



by fibres derived from the nucleus gracilis and the nucleus 

 cuneatus of the opposite side. The nucleus gracilis and the 

 nucleus cuneatus lie in the upper ends of the fasciculi of 

 the same names, and the fibres which pass from them to the 

 lemniscus of the opposite side decussate with similar fibres 

 derived from the opposite gracile and cuneate nuclei, in the 



