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  2. Threshold potential - Wikipedia

    en.wikipedia.org/wiki/Threshold_potential

    In electrophysiology, the threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential. In neuroscience , threshold potentials are necessary to regulate and propagate signaling in both the central nervous system (CNS) and the peripheral nervous system (PNS).

  3. Action potential - Wikipedia

    en.wikipedia.org/wiki/Action_potential

    Action potentials are triggered when enough depolarization accumulates to bring the membrane potential up to threshold. When an action potential is triggered, the membrane potential abruptly shoots upward and then equally abruptly shoots back downward, often ending below the resting level, where it remains for some period of time.

  4. Summation (neurophysiology) - Wikipedia

    en.wikipedia.org/wiki/Summation_(neurophysiology)

    Whether threshold is reached, and an action potential generated, depends upon the spatial (i.e. from multiple neurons) and temporal (from a single neuron) summation of all inputs at that moment. It is traditionally thought that the closer a synapse is to the neuron's cell body, the greater its influence on the final summation.

  5. Cardiac action potential - Wikipedia

    en.wikipedia.org/wiki/Cardiac_action_potential

    The slope of phase 0 on the action potential waveform (see figure 2) represents the maximum rate of voltage change of the cardiac action potential and is known as dV/dt max. In pacemaker cells (e.g. sinoatrial node cells ), however, the increase in membrane voltage is mainly due to activation of L-type calcium channels.

  6. Axon hillock - Wikipedia

    en.wikipedia.org/wiki/Axon_hillock

    The axon hillock and initial segment have a number of specialized properties that make them capable of action potential generation, including adjacency to the axon and a much higher density of voltage-gated ion channels than is found in the rest of the cell body. [5]

  7. All-or-none law - Wikipedia

    en.wikipedia.org/wiki/All-or-none_law

    The magnitude of the action potential set up in any single nerve fibre is independent of the strength of the exciting stimulus, provided the latter is adequate. An electrical stimulus below threshold strength fails to elicit a propagated spike potential. If it is of threshold strength or over, a spike (a nervous impulse) of maximum magnitude is ...

  8. Subthreshold membrane potential oscillations - Wikipedia

    en.wikipedia.org/wiki/Subthreshold_membrane...

    Neurons produce action potentials when their membrane potential increases past a critical threshold. In order for neurons to reach threshold for action potential to fire, enough sodium (Na+) ions must enter the cell through voltage gated sodium channels through membrane and depolarize the cell. [ 1 ]

  9. Myogenic mechanism - Wikipedia

    en.wikipedia.org/wiki/Myogenic_mechanism

    It is usually due to ion channels in the cell membrane that spontaneously open and close (e.g. If channels in cardiac pacemaker cells). When the membrane potential reaches depolarization threshold an action potential (AP) is fired, excitation-contraction coupling initiates and the myocyte contracts. [citation needed]