The Nervous System - Nervous, Sensory, and Motor Systems...

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Nervous, Sensory, and Motor Systems Nerves - nerve cell is called a neuron - each may communicate with 1000s of other nerve cells - cell body (has nucleus, mitochondria, organelles) - dendrites: incoming info - axon: outgoing info (towards next neuron) Nerve: bundles of axons - blood vessels, connective tissue – is an ORGAN How nerves work: The plasma membrane is not permeable to charged ions - positive ions are kept OUT; negative ions are kept IN - membrane (or “resting”) potential: tension between opposite charges (= potential energy) - Action Potential - transmission of signal occurs as a consequence of a voltage change across membrane - voltage change results in a permeability changes across membrane: - ion channels open; Na ions flood IN and K ions flood OUT - afterwards: other channels open to let positive ions back out - “back signals” (movement of nerve impulse in opposite direction) is not possible because there is no signal propagation where the positive ions are leaving The Synapse:
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This note was uploaded on 02/08/2011 for the course BIOLOGY 101 taught by Professor Weinstein during the Fall '07 term at University of Tennessee.

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The Nervous System - Nervous, Sensory, and Motor Systems...

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