BIOL 14108 Chapter Notes - Chapter 9: Foramen Magnum, White Matter, Pineal Gland
24 Jan 2016
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Neuroglia assemble in a special, protective way in the brain. Most capillaries are leafy allowing small molecules to enter/leave bloodstream, making cells in brain more connected. Pns neuroglia include: schwann cells produce myelin sheaths in pns. Neurons vary in size, but are similar in features. Include: cell body, dendrites and an axon: cell body. Cell body consists of granular cytoplasm, cell membrane, mitochondria, lysosome, golgi apparatus and neurofibrils. Scattered through the cytoplasm are chromatophillic substances (nissl bodies) with rough endoplasmic reticulum: dendrites. This is the neuron"s main receptive surface with which axons of other neurons communicate: axons. Axons rise as a single structure, but give off side branches. Larger axons enclosed by myelin sheaths produce schwann cells. Parts of schwann cells that contain the most cytoplasm and nuclei remain outside the myelin sheath and compose neurilemma (neurilemmal sheath). There are narrow graps between each schwann cell, these are called nodes of. Axons that are with myelin sheaths are called myelinated.
