122 Neurological Technique 



ib) Cerebrum. 



1. Mesencephalon. 



Corpora quadrigemina. 

 Pedunculi cerebri. 



2. Prosencephalon. 



Diencephalon (Thalamencephalon, etc.). 

 Telencephalon. 



For further detail as to the subdivisions see neurological 

 nomenclature, and figs. 3 and 4, pp. 143 and 144. Identify the 

 structures composing the so-called Rhinencephalon. 



in. STUDY OF THE DIVISIONS OF THE ENCEPHALON. 



[a) Rhombencephalon and mesencephalon. — Lift the posterior 

 overhanging portion of the cerebellum and observe that it over- 

 lies the ventriculus quartus. Divide the cerebellum along the 

 vermis superior, taking care that the knife, in passing through 

 the vermis inferior, does not injure the floor of the ventriculus 

 quartus, but does divide the velum medullare anterius (valve of 

 Vieussens) up to the colliculi inferiores of the mesencephalon. 

 Then remove the cerebellar hemisphere by severing the cere- 

 bellar peduncles, viz., brachium conjunctivum (superior), bra- 

 chium pontis (middle), and corpus restiforme (inferior peduncle). 

 These come together as one and can be distinguished only by 

 careful examination after the incision. 



(3) Make a drawing of the parts of the rhombencephalon 

 now exposed, illustrating the appearance, position, and relations 

 of the following structures : 



1. The dorsal and lateral surface of the medulla oblongata 

 showing the funiculus cuneatus and tuberculum cuneatum, funi- 

 culus gracilis and clava, and the fissura mediana posterior ; the 

 ventriculus quartus with its calamus scriptorius, taenia ventriculi 

 quarti, sulcus longitudinalis, fossae rhomboideae, striae medul- 

 lares (striae acusticae), colliculi faciales, and foveae superior 

 and inferior ; the corpus restiforme and tuberculum acusticum. 



2. The Pons, with brachium pontis and brachium conjunc- 

 tivum. 



3. The Cerebellum, showing the vermis superior with its 



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