EXSC 224 Lecture Notes - Lecture 3: Resting Potential, Axon Hillock, Axon Terminal
Document Summary
Name the cell types that create myelin and what part of the neuron are they associated: glial cells - oligodendrocytes and schwann cells on the axons. Graded potentials are essential for causing action potentials. Action potential is caused by permeability changes in the plasma membrane. Notice the unit of time - milliseconds! Takes about 4 milliseconds for an action potential to complete. You can have at least 250 action potentials in one second. 55mv is the threshold you must reach to trigger an action potential. If you don"t reach threshold, nothing happens. Resting state >> depolarization >> repolarization >> hyperpolarization >> resting states. When you hyperpolarize the potassium channel closes. Only leakage channels for na and k are open. All gated na and k channels are closed. Working to establish equilibrium & maintain membrane potential at-70mv. Threshold - opens up sodium gated channels. Na rushes into cytosol, making the cell very positive (+30mv at peak)
