You generate action potentials in a neuron bathed in solution in a petri dish by applying a threshold-level depolarizing stimulus near its axon hillock. If the solution surrounding the neuron contained 5mM K+, 150 mM Na+, and 0 mM Ca2+ which of the following would you expect? The neuron would not be able to propagate action potentials down the entire length of the axon O The neuron would not release neurotransmitter from the axon terminal O The neurons action potentials would have an unusually long duration O The neuron would have a resting membrane potential of zero

You generate action potentials in a neuron bathed in solution in a petri dish by applying a threshold-level depolarizing stimulus near its axon hillock. If the solution surrounding the neuron contained 5mM K+, 150 mM Na+, and 0 mM Ca2+ which of the following would you expect? The neuron would not be able to propagate action potentials down the entire length of the axon O The neuron would not release neurotransmitter from the axon terminal O The neurons action potentials would have an unusually long duration O The neuron would have a resting membrane potential of zero

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter4: Principles Of Neural And Hormonal Communication

Section: Chapter Questions

Problem 3TAHL

See similar textbooks

Similar questions

Assume presynaptic excitatory neuron A terminates on a postsynaptic cell near the axon hillock and presynaptic excitatory neuron B terminates on the same postsynaptic cell on a dendrite located on the side of the cell body opposite the axon hillock. Explain why rapid firing of presynaptic neuron A could bring the postsynaptic neuron to threshold through temporal summation, thus initiating an action potential, whereas firing of presynaptic neuron B at the same frequency and the same magnitude of EPSPs may not bring the postsynaptic neuron to threshold.
Figure 35.11 Potassium channel blockers, such as amiodarone and procainamide, which are used to treat abnormal electrical activity in the heart, called cardiac dysrhythmia, impede the movement of K+ through voltage-gated K+ channels. Which part of the action potential would you expect potassium channels to affect?
In an experiment, the extracellular [Na+] surrounding a nerve cell was reduced from 145 to 45 mM. Which of the following is the most likely effect of this on action potentials? No action potentials would occur because the concentration of extracellular Na+ is too low. The membrane potential would become more negative so the threshold for action potential generation could not be reached. The nerve cell would still produce an action potential but its amplitude would be reduced and the depolarisation phase would be slower. The nerve cell would still produce an action potential but its amplitude would be reduced and the depolarization phase would be more rapid.
For a nerve fibre axoplasmic and extracellular ion concentrations were found to be respectively: Na+, 15 and 115 mM; K+, 90 and 3 mM; Cl-, 10 and 120 mM. Resting potential was -78 mV. Halving the external [Na+] caused a very slight hyperpolarization; doubling external [K+] caused considerable depolarization; halving the external [Cl-] had no effect. In each case the ions were replaced by impermeable salts. What can you deduce (with reasons) about the resting membrane conductances?
You are recording the resting membrane potential from a neuron placed in a petri dish. The following oscilloscope tracing shows the voltage measured when a microelectrode tip is placed just inside the axon. The solid line on the oscilloscope is obtained when the neuron is placed in a control solution containing 5mM K+ and 150 mM Na+. The solution is then changed and a second recording is made, shown by the dashed line on the tracing. You can reasonably conclude this new solution: a) has increased concentration of K+ b) has increased concentration of Na+ c) has decreased concentration of K+ d) has decreased concentration of Na+
A graded potential that achieves threshold leads to the generation of an action potential. Which one of the following statement/s regarding graded and action potentials is/are true? O graded potentials result from the opening of chemically gated sodium channels O action potentials result from the opening of voltage gated sodium channels O graded potentials result from the opening of calcium gated channels and action potentials result from the opening of sodium gated channels a and b Next
You are recording the resting membrane potential from a neuron placed in a petri dish. The following oscilloscope tracing shows the voltage measured when a microelectrode tip is placed just inside the axon. The solid line on the oscilloscope is obtained when the neuron is placed in a control solution containing 5mM K+ and 150 mM Na+. The solution is then changed and a second recording is made, shown by the dashed line on the tracing. You can reasonably conclude this new solution: Membrane Potential (mV) 989 20 -80 HORRETAN 0 1 2 3 4 5 6 7 8 9 10 Time (sec) has decreased concentration of K+ Ohas decreased concentration of Na+ has increased concentration of K+ 1. has increased concentration of Na+
If action potential propagation from one neuron to another neuron requires ACh release, what event at the synaptic cleft explains the need for action potentials to arrive at a high rate before the post-synaptic membrane achieves threshold? the lack of sodium voltage gated channels on the post-synaptic membrane O the rapid breakdown of ACh by ACHE at the synaptic cleft the slow release of ACh by the synaptic vessicles the slow movement of sodium through chemical gates Previous Next MacBook Air
Which of the following statements is TRUE about the depolarization phase of action potential? Group of answer choices: Na-K pump initiates depolarization. Potassium ion channels quickly opens to allow efflux of ions. Depolarization is characterized by the movement of calcium ions out of the cell. Depolarization is primarily triggered by opening of sodium ion channels asap pls
Assume the membrane is only permeable to Na+ and K+, the electrical model of axon membrane is the following: Outside A INa gna ENa Ex D Inside The membrane potential at rest and at peak is -70mV and 45mV respectively; the potential of Sodium ion is 60mV and the potential of Potassium ion is -80mV. Find the ratio 9Na at rest and at peak. gK
1) A 100-um diameter nerve axon has the following properties: rm = 2.5 x 104 ohm x cm, ri = 1 x 105 ohm/cm, r0 = 0, cm = 3 x 10-8 F/cm. The permeability to Cl- is very high and Cl- ions are at resting potential Vm. A steady inward current is injected into the axon resulting in a Vm of -110 mV at the site of current injection. If the Vm 3 mm from the site of injection is -94.5 mV, what is the resting Vm?
You are recording the electrical activity of a cell body with a resting membrane potential of -70 mV. Three different stimuli are detected by 3 different dendrites at the same time, each changes the voltage of the dendrite to -65 mV. However, the voltage change detected in the cell body of that neuron, is -55 mV. What happened? O temporal summation of IPSPS O spatial summation of IPSPS O temporal summation of EPSPS O spatial summation of EPSPS