Introduction to Laboratory 7:
The Prosection

Finally ... Test yourself on the Brainstem Slides of the Week for Week 7.

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A special dissection (prosection) will be demonstrated by instructors to each of the laboratory groups. The internal structures of the cerebral hemispheres, particularly those related to the "C" shaped lateral ventricles, will be revealed by 3 cuts: 1. To remove the top portion of the hemisphere to the roof of the ventricles, and 2. A connecting vertical cut through the parietal lobe, followed by, 3. A cut running the length of the middle temporal gyrus to the depth of the ventricle and to the temporal pole.

The dissection described above, plus a little more, allows the corpus callosum and the back of the brain and the ventral part of the temporal lobe to be removed as a unit. The "C" shaped fornix, which sets a medial limit to the lateral ventricle, will be the most intriguing structure in the dissection. Additional features of the brain stem and ventricles are also well revealed by these dissections. Select the button below to begin.

Study Questions

1. What relationship do each of the cerebellar peduncles have to the IVth ventricle?
   
   
2. Where is the reticular formation of the brainstem located?
   
   
3. Internal arcuate fibers of the medulla arise from dorsal column nuclei and project to which thalamic nucleus?
   
   
4. At what cross sectional level of brainstem is the red nucleus found?
   
   
5. Find the nuclei for cranial nerves 6, 8, 10 and 12 in the floor of the fourth ventricle.
   
   
6. What cranial nerve approaches brain stem dorsal to the inferior Cerebellar Peduncle?
   
   
7. Review the blood supply to the brainstem, cerebellum and internal capsule. (atlas, 6th pg. 110, 124, 136, and 158. 7th pgs 113, 127, 139, and 161)
   
   
8. What two motor cranial nerves exit from the medulla near the pyramid?
   
   
9. What cranial nerves contain axons from the cells in the nucleus ambiguous?
   
   
10. What cranial nerve nucleus lies deep to the genu of the VII cranial nerve?
    
    
11. What cranial nerve nucleus sends axons into the interpeduncular fossa?
    
    
12. Locate the cell bodies of the cranial nerve which exits from the dorsum of the brainstem (look at the inferior colliculus level).