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Questions and Answers
What causes depolarization in a cell?
What is the main cause of hyperpolarization in a cell?
What are graded potentials primarily caused by?
What is the duration of graded potentials?
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What is the threshold for action potentials?
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Depolarization is due to the net flow of positive charges into the cell or negative charges to regions outside the cell. Hyperpolarization is due to the net flow of negative charges into the cell or positive charges outside the cell. Such changes in ion permeability are often termed changes in the ______
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There are two qualitatively different types of axon excitations: graded potentials and ______
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Graded potentials are minor perturbations in the membrane potential due to the binding of neurotransmitters, the stimulation of sensory reception, or spontaneous ion leakage through the cell ______
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There is no threshold needed to stimulate a graded potential. They last for 5 ms to several min. Graded potentials can be either membrane depolarizations or ______
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Action potentials are qualitatively different from graded potentials in every way. They initially have relatively large depolarizations by ~15– 20mV. The potential lasts for 1–5 ms, and they have a threshold of about ~ −55 mV. 3. Action potentials are propagated over long distances along the ______
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