70 

 THE CENTRAL NERVOUS SYSTEM. 



LABORATORY WORK FOR THE WEEK. 



References : 



Points for Quiz : 



Laboratory Report : 



Due : 



Go to the delivery desk for (a) paraffin section i6o, (5) prepar- 

 ations already stained i6i, 162, 164-168, (c) section 163 will be 

 given you some time during the first period. 



MYEL (SPINAI, cord). 



160. Cervical myel. Transection, vom Rath's 



fluid ; paraffin ; sections /t. Stain with hematoxylin 2-3 



hours, picric alcohol 30 seconds or longer. 



Gross anatomy : Examine the preparations of myel, noting the 

 three regions — cervical, thoracic and lumbar ; the end of the seg- 

 ment of myel, observing the halves separated by the dorsal septum 

 and the ventral fissure, the central gi;ay matter, cinerea, and the 

 superficial, ectal alba (white matter) ; the spinal nerves formed by 

 the union of a dorsal and a ventral root, the former with an enlarge- 

 ment — the ganglion. 



In the section recognize («) the lateral halves, (b) the ventral 

 fissure, (c) the dorsal septum, {d) the central cavity — myelocoele 

 with its lining epithelium — endyma. In the cinerea note {i) the 

 rough division into lateral masses connected by a commissure 

 surrounding the myelocoele, (2) the dorsal and ventral cornua. In 

 studying the structure of the cinerea note (a) the general 

 structural appearance of the substantia spongiosa and substantia 

 gelatinosa, {b) the size and character of the nerve cells in the ven- 

 tral cornua, in the dorsal cornua, and intermediate region. Con- 

 sider the significance of the large cells of the ventral cornu. In the 

 alba, distinguish the dorsal columns and the roughly defined lateral 



