Aukcioni online dating

The undershoot phase occurs because unlike voltage-gated sodium channels, voltage-gated potassium channels inactivate much more slowly.Nevertheless, as more voltage-gated K channels become inactivated, the membrane potential recovers to its normal resting steady state..The Hodgkin–Huxley model of an action potential in the squid giant axon has been the basis for much of the current understanding of the ionic bases of action potentials.Briefly, the model states that the generation of an action potential is determined by two ions: Na and K .

Although slower than ionotropic receptors that function as on-and-off switches, metabotropic receptors have the advantage of changing the cell's responsiveness to ions and other metabolites, examples being gamma amino-butyric acid (inhibitory transmitter), glutamic acid (excitatory transmitter), dopamine, norepinephrine, epinephrine, melanin, serotonin, melatonin, and substance P.When ionotropic receptors are activated, certain ion species such as Na to enter the postsynaptic neuron, which depolarizes the postsynaptic membrane.If more of the same type of postsynaptic receptors are activated, then more Na will enter the postsynaptic membrane and depolarize cell.As Na ions enter the cell, the membrane potential is further depolarized, and more voltage-gated sodium channels are activated.Such a process is also known as a positive feedback loop.

Leave a Reply