Search results
Results from the WOW.Com Content Network
The action potential generated at the axon hillock propagates as a wave along the axon. [50] The currents flowing inwards at a point on the axon during an action potential spread out along the axon, and depolarize the adjacent sections of its membrane.
Once this initial action potential is initiated, principally at the axon hillock, it propagates down the length of the axon. Under normal conditions, the action potential would attenuate very quickly due to the porous nature of the cell membrane. To ensure faster and more efficient propagation of action potentials, the axon is myelinated ...
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.
Figure B. is a recording of an actual action potential N.B. Actual recordings of action potentials are often distorted compared to the schematic view because of variations in electrophysiological techniques used to make the recording. In neurophysiology, a dendritic spike refers to an action potential generated in the dendrite of a neuron ...
The action potential generated by the SA node passes down the electrical conduction system of the heart, and depolarizes the other potential pacemaker cells (AV node) to initiate action potentials before these other cells have had a chance to generate their own spontaneous action potential, thus they contract and propagate electrical impulses ...
The action potential travels from one location in the cell to another, but ion flow across the membrane occurs only at the nodes of Ranvier. As a result, the action potential signal jumps along the axon, from node to node, rather than propagating smoothly, as they do in axons that lack a myelin sheath.
As an example, the cardiac action potential illustrates how differently shaped action potentials can be generated on membranes with voltage-sensitive calcium channels and different types of sodium/potassium channels. The second type of mathematical model is a simplification of the first type; the goal is not to reproduce the experimental data ...
Within the same neuron, a receptor potential can cause local current to flow to a region capable of generating an action potential by opening voltage-gated ion channels. [4] A receptor potential can also cause the release of neurotransmitters from one cell that will act on another cell, generating an action potential in the second cell. [4]