ANP 1105 Chapter Notes -Axon Hillock, Nissl Body, Myelin

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: Joanne Savory

Document Summary

Structural units of ns: conducts electrical impulses from one body part to another. Special features: extreme longevity: adequately nourished (100 years, amitotic: does not undergo cell division, high metabolic rate: brain consumes 20% of body"s energy. Large, complex cells: all have a cell body + one or more processes. Three functional regions of neuron: receptive region, conducting region, secretory region. Action potential is initiated at the axon hillock (initial conductive region) and travels down the dendrites via salutatory conduction over the myelin sheath. Large, spherical nucleus + granular cytoplasm = biosynthetic cenre. Extensive rer + ribosome clusters (nissl bodies); also elaborate golgi & lots of mitochondria. Nucleus is collection of neurons with a common function in the cns (double-check) Ganglion is a collection of neurons with a common function in the pns. Dendrites (receptive region: short, tapering, branched extensions; usually hundreds/cell body, enormous sa for reception from other neurons, conducts impulses toward cell body, short distance, graded potentials.