A LABORATORY OUTLINE OF NEURO-ANATOMY 365 



of the seventh nerve. Locate the spinal tract of the fifth nerve and its nucleus, the 

 trapezoid body, and superior olivary nucleus (Fig. 108; pp. 151-154). 



61. Section Through the Middle of the Pans Showing the Motor and Main Sensory 

 Nuclei of the Fifth Nerve. In addition to these nuclei note the beginning of the mesen- 

 cephalic root of the fifth nerve. The brachium conjunctivum makes its appearance 

 in the dorsal part of the section (Fig. 110; pp. 154-157). 



62. Section Through the Inferior Colliculus. Identify the basis pedunculi, substantia 

 nigra, medial and lateral lemnisci, cerebral aqueduct, central gray matter, mesence- 

 phalic root of the fifth nerve, fasciculus longitudinalis medialis, nucleus of the trochlear 

 nerve, and the decussation of the brachium conjunctivum (Figs. 113, 114; pp. 158, 165). 



63. Section Through the Superior Colliculus. Identify, in addition to the structures 

 continued upward from lower levels, the red nucleus, the nucleus of the third nerve, 

 and the root fibers of that nerve, the ventral and dorsal tegmental decussations, the 

 inferior quadrigeminal brachium, and the medial geniculate body (Fig. 116; pp. 160, 

 167). 



THE CEREBELLUM 



64. Compare the human cerebellum with that of the shark and the sheep. How 

 is its size related to the size of the pons and to the extent of the cerebral cortex? 



65. On both the human and sheep's cerebellum identify the vermis, hemispheres, 

 and divided peduncles (Figs. 138, 139, 143-145). In the medial sagittal section of 

 the sheep's brain identify the white medullary body of the cerebellum, the arbor 

 vitae, cerebellar cortex, folia, and sulci (Fig. 84; pp. 196-199). 



66. Study the morphology of the cerebellum in the sheep (Figs. 143-145). Lo- 

 cate these same fundamental subdivisions in the human cerebellum (Figs. 146, 147). 

 What functions have recently been assigned to each of these subdivisions? (See 

 pp. 199-203.) 



67. Divide the human cerebellum in the median plane. Cut the right half into 

 horizontal sections and the left into sagittal sections and study the medullary center 

 and nuclei of the cerebellum (Figs. 140, 141, 148; pp. 199, 203). 



68. Study the histologic sections of the cerebellar cortex and master the details 

 of its structure (Figs. 150, 151; pp. 206-210). 



FUNCTIONAL ANALYSIS OF THE BRAIN STEM 



69. Review the sections of the brain stem as directed in the following paragraphs, 

 paying special attention to the functional significance of the various nuclei and fiber 

 tracts as far as they can be followed in the series of sections. In general, the afferent 

 tracts and nuclei should be entered in color on the right side of the drawings already 

 made, and the efferent tracts and nuclei on the left side. But this order must be re- 

 versed in certain cases to allow for the decussation of the tracts. Label the various 

 tracts and nuclei. Use the following color scheme: 



Somatic afferent: 



Exteroceptive blue . 



Proprioceptive yellow. 

 Visceral afferent orange. 

 Visceral efferent purple. 



