BIOL 339 Chapter Notes - Chapter 5: Positive Feedback, Neurotransmitter, Saltatory Conduction
23 Sep 2016
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Integration zone cell body (soma), receives additional signals: conduction zone axon transmission of electrical impulses a. Impulses are away from cell body: myelinated sheath, nodes of ranvier, output zone axon terminals, communication with other cells. Dendrites: responsible for sensing incoming signals, converting signals to electrical signals: electrical signals are in a form of change in membrane potential, transition of signals to cell body. Axon hillock: signal integration regulator: conduction of signals from dendrites and cell body. T temperature (kelvin) z valence of ion. Tells us about reduction potential of a half cell/ total voltage. Sum of equilibrium potentials for all relevant ions: weighting factor takes into account the relative permeabilities of the ions, pion. Triggered by membrane potential at axon hillock reaching threshold. , membrane potential ~+30 mv: repolarization phase: Membrane potential rapidly returns to resting membrane potential. Becomes more negative than resting membrane potential: may approach k+ equilibrium potential, hyperpolarization phase: Size and duration varies greatly among neurons.
