Slices

Coronal Slice

Here is a big thick slice. This a coronal slice (think parallel with the front of the body , down through the middle) which illustrates beautifully the grey-white-grey organization of the cortex, tracts, and basal ganglia (gray stuff beneath the surface). The grey areas contain more cell bodies, the white areas are jam packed with myelinated axons (which function sort of like insulated wires) connecting cells to other cells

Slice is the cool-kid word for cross-section of brain. If you’re preparing a slice for the microscope, it’s gonna be thin, really thin, so that the light can shine up through it and you can see cells. Think about the time you spent working at the deli, how some people wanted their cold cuts really thin, and others wanted them weirdly thick. Microscope bound slices of brain are ideally only a few cells thick. Slices bound for gross anatomical identification, to sit out on a table and have undergraduates poke at them, are going to be thicker.

Learning the brain, brain stem and spinal column through slices seems to me to be a little bit like learning to drive. Before I got a learner’s permit, I never paid much attention to where things were in relation to other things. But when I began driving, a series of ephinaies “Ah hah! Making a right at the end of Beekman Ln brings me to the Middle School!” taught me how everything was connected. Rather embarrassingly, in my grandfather’s town, I knew the bagel store, (named, in some stroke of genius, Two if Buy Bagel) and I knew the supermarket, but I did not realize until I had a drivers license that they were actually on the same road, only about a mile or two apart.

This may speak more to a certain kind of detached and spacey childhood than anything else.  But to learn the brain and brain stem in slices is a process of viewing independent, floating segments of a big and interconnected mess (one that really would never naturally be seen in isolated pieces) and trying to reconstruct the roads in and out of the place from you memory of the thing as a whole.

Ah hah, this tract veers laterally because these other tracts appear.  Codes and latin names.

My favortie mnemonic, for structures lining the fourth ventricle at the level of the Rostral Medulla; Has Death Stopped Vice In Central Park? Hypoglossal nucleus, DMX, Solitary nuclues, Vestibulochchlear complex, Inferior Cerebellar Peduncle.

Now, how to pull it together for the next exam.  I always make the stupidest mistakes.

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