From Wikipedia, the free encyclopedia
Jump to: navigation, search ...
(Date:3/29/2011)... interventional radiology treatment for the noncancerous yet very ... of the uterusimproves a number of women,s lower ... those fibroids, confirm researchers at the Society of ... Ill.
An electrical state in an excitable cell whereby the inside of the cell is made less negative relative to the outside than at the resting membrane potential.
Certain external stimuli reduce the charge across the plasma membrane.
Change in the potential that normally exists across the plasma membrane of a cell at rest, resulting in a less negative membrane potential.
of the T-tubule membrane causes a release of calcium ions from the sarcoplasmic reticulum, triggering muscle contraction.
depolarization The loss of an electrical charge on the surface of a membrane.
depolarized The reduction in the difference in charge (potential) between the outside and inside of a membrane.
- a shift in the membrane potential to a less negative value; triggered by an action potential
epithelial tissues (epithelium) - cells tightly bound together into sheets ...
In most neurons, depolarizations are graded only up to a certain membrane voltage, called the threshold.
The of the pre-synaptic membrane results in the opening of voltage gated calcium channels.
The depolarization travels in one direction down the axon of the neuron to the opposite end of the cell. At the "far" end, the neuron has small vesicles containing a neurotransmitter which is released when the membrane depolarization occurs there.
The resulting activation of voltage-gated Na+ channels boosts the graded produced by TRPM5 to the high voltage threshold required for gating the gap-junction hemi-channels. Romanov et al.
This change in the membrane potential, called depolarization, will cause the voltage-gated sodium channels to open. Sodium ions will rush in, resulting in a rapid change in the charge.
An increase in the threshold for an action potential that occurs in some neurons during a slowly developing or prolonged .
The beat is actually much more complex and involves other ions. But the end result of this depolarization-repolarization is that the contractile filaments in the cell engage, and the cell contracts.
Search the Web
Custom Search ...
There is an area, however, which does conduct in the septum, and the waves can pass from here through the ventricles. This specialised area is called the atrioventricular node (AVN) and will pass on the waves of after about 0.1s.
See also: Membrane, Action, Cell, Trans, Cells