BIOC21H3 Study Guide - Franz Nissl, Neuroglia, Axon
16 Sep 2012
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Document Summary
Cell body (soma or perikaryon), nucleus, axon, dendrites, abundant nissl substance (rer), myelin. Helps speed up transmission of impulse salutatory conduction. Composition: 70-80% lipid, and some protein made from a cellular membrane. Large, very pale nucleus (lots of euchromatin) with a dense nucleolus (owl"s eye nucleus) Cellular processes not normally visible (not all neurons look the same) One axon transmits action potential to other cells/neurons. Believed to originate in the bone marrow. Form a simple columnar covering the ventricles of the. In contact with astrocytes forms a barrier. Short, spiny processes processes appear to have small spikes cell can thus produce several internodes. Variable diameter along length it changes. Some have dendritic spines important for proper brain development; highly elongated in young people and shorten with age. Axon hillock is normally free of any ribosomes or rer = poor staining initial segment follows. Diameter affects speed of impulse transmission diameter more uniform throughout.
