February 25 - -55 o Ex In potassium channel potassium would...

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February 25 Acetylcholine: transmitter of nerve impulses, excitatory in skeletal muscle, inhibitory at SA Node There are different receptors in different parts of the body allowing acetylcholine to have different effects Ligand gated channel: Na/K ATPase Voltage-Gated Na Channels Voltage-Gated K Channels Voltage-Gated Calcium Channels The threshold is -55 mV When pre-synaptic neuron goes back to normal you don’t want neurotransmitter o In synaptic cleft: enzymes that breaks down transmitters, inactivate them o Reuptake of the transmitter into pre-synaptic cell and recycles it Excitatory neurotransmitter attaches to ligand gated channel, change in conformation and sodium goes in to depolarize membrane, increasing the likelihood of firing an action potential , goes from -70 to -80 Inhibitory neurotransmitter attached to gated channel and Cl goes in but membrane stays polarized (hyperpolarized), decreasing the likelihood of firing an action potential, stays at
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Unformatted text preview: -55 o Ex. In potassium channel: potassium would leave o Or Chloride channels open and chloride in • If both are applied then they cancel each other out • Sodium-potassium ATPase: working overtime in neurons, when potassium leaves goes back to resting potential, on upstream side sodium is • Potassium helps bring neuron to resting potential by leaking across membrane • Myelination: layers of fat that go around axon, it stops the charge from leaking out of the membrane as it spreads down the axon • Na+/K+ ATPase: creates the electochemical gradient favoring the outflow of K= when the cell is at rest positive feedback because once sodium channels open and begin to depolarize the membrane they become more likely to open • Sodium moves into and out of the cell via ion channels, its not sodium-potassium pump because it only moves sodium out • Shwann cells form myelin sheath...
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  • Winter '11
  • Pytel
  • myelin sheath, voltage-gated Na channels, voltage-gated calcium channels, Excitatory neurotransmitter attaches, fi ring

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February 25 - -55 o Ex In potassium channel potassium would...

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