Concept explainers
Sequence the following list of events of a neuronal action potential by placing 1 next to the first event, 2 next to the second event, and so on.
a. _______ The activation gates of voltage-gated
b. _______
c. ________ Local potentials depolarize the membrane to threshold.
d. ________ The inactivation gates of voltage-gated
e. ________ Repolarization continues and Na+ channels return to resting.
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Human Anatomy & Physiology
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- which one of the following statements is incorrect? a. temporal summation occurs when a single synaptic input is activated twice in succession, with the second postsynaptic potential occurring before the first postsynaptic potential is over. b. blocking voltage-gated k* channels in the presynaptic membrane of a typical chemical synapse is likely to reduce the amount of neurotransmitter released in response to a single action potential in the presynaptic axon. c. in the optic tectum of the hunting rattlesnake, spatial summation is used to combine inputs from visual and thermoreceptive layers in order to make a decision whether to strike at a mouse-like object. d. a single type of neurotransmitter can have different postsynaptic actions depending on the type of receptor to which it binds.arrow_forwardWhat type of synaptic potential (if any; be sure to indicate if any modification is occurring as well) would occur if: a.) An MAO inhibitor type of antidepressant is functioning at an active dopaminergic synapse that increases the rate of sodium flowing into the cell. b.) Prozac is present at an active serotonin synapse where receptor activation increases the flow of potassium out of the cell.arrow_forward+70 D A -70 Time in msec The diagram above shows the changes in membrane potential measured from a single point in a typical mammalian motor neuron that has been artificially stimulated to threshold. Membrane potential in mV Barrow_forward
- excitatory and 15 inhibitory postsynaptic potentials appear simultaneously on the plasmatic membrane of motoneuron. Answer the question A and fulfill the task B:A) Will this neuron generate the efferent nervous impulses if the amplitude of single EPSP and IPSP appeared on the axonal hillock`s membrane equals 1 mV? Why?B) Name the state of this neuron and name the type of summationarrow_forwardConsider the following three diagrams of a nerve cell membrane. They show resting potential, depolarization, and hyperpolarization. Figure out which one is which, then draw them in the order they occur in a cell that undergoes an action potential outside + Na* inside K* Na* Nat K Nat K Na potential: -80 mV outside + Na K* Na* inside Na+ K Nat Na* K+ potential: +30 mV outside Na Na Na Na* K+ inside K* Na* Kt potential: -70 mVarrow_forwardMark the following statements as true or false. If a statement if false, correct it to make a true statement. a. An excitatory postsynaptic potential is caused by K+ or Clchannels opening in the membrane of the postsynaptic neuron. b. Postsynaptic potentials may summate by spatial summation in which multiple neurons fire onto a single postsynaptic neuron. c. An inhibitory postsynaptic potential causes the membrane potential of the postsynaptic neuron to approach threshold. d. Spatial summation can combine two EPSPs, two IPSPs, or an EPSP and an IPSParrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning