82 LABORATORY OUTLINE OF NEUROLOGY 



99. Microscopic structure of the cerebellar cortex. — Examine 

 and draw the sections of cerebellar cortex provided, and with the 

 aid of your reference books build up a mental picture of the 

 connections of the different types of cortical neurons. See 

 Herrick ('15), Fig. 89 and the accompanying discussion, and 

 references cited at the end of Section 100. 



100. Structure, subdivision, and functions of the cerebellum. — 

 Compare the external form of the cerebellum in the fish, sheep, 

 and man, and note that variations in the size of the cerebellar 

 hemispheres are correlated with those of the pons. What are 

 the fiber connections of the pons, and with what remote part of 

 the brain is it in functional connection? Identify the vermis, 

 hemispheres, and flocculus of the cerebellum. Arbor vitw 

 is a name given to the appearance of the cerebellar gray and 

 white matter as seen in median section of the vermis. 



The cerebellum is a great proprioceptive center of coordina- 

 tion. We have already learned that it is connected by afferent 

 fiber tracts with the primary basal proprioceptive apparatus of 

 the spinal cord and brain stem. And it is also intimately related 

 with the cerebral cortex through the cortico-pontile fiber tracts 

 (Section 96, c). Nervous mechanisms' for the performance of 

 all simple reflex and voluntary acts are provided in other parts 

 of the central nervous system; but the participation of the 

 cerebellum is necessary for the performance of all complex 

 movements, especially for equilibration, motor coordination, 

 and the maintenance of muscular tone. 



The human cerebellum is subdivided anatomically into a very 

 large number of parts, the names of which are given in all of the 

 larger text-books of anatomy. Recent investigations of the 

 comparative anatomy, comparative embryology, experimental 

 physiology, and pathology of the cerebellum have revealed a 

 rather obscure type of functional localization within the cere- 

 bellum which bears no simple relation to the anatomical sub- 

 divisions as denned in the BNA tables. 



Broadly speaking, there are centers within the cerebellar 

 cortex for muscular coordination and tonic control of the more 

 cephalic parts of the body in the dorsal and rostral parts of the 

 cerebellum. Centers for the similar control of the more caudal 

 muscular complexes extend around the caudal margin of the 



