Which of the following statements regarding graded potentials is FALSE? Graded potentials: diminish in strength over distance. can add up (summate) to produce greater depolarizations. can vary in strength and can even hyperpolarize a membrane. are generated in the dendrites and cell body of a neuronal cell. are always of equal magnitude and travel over long distances along axons.

Which of the following statements regarding graded potentials is FALSE? Graded potentials: diminish in strength over distance. can add up (summate) to produce greater depolarizations. can vary in strength and can even hyperpolarize a membrane. are generated in the dendrites and cell body of a neuronal cell. are always of equal magnitude and travel over long distances along axons.

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 4TAHL: Assume presynaptic excitatory neuron A terminates on a postsynaptic cell near the axon hillock and...

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.
A neuron responds to adequate stimulation with _______, a type of self-propagating signal.
Draw and label an action potential, indicating the ion movements responsible for the rising phase and the falling phase.
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.
Which of the statements below describe a situation in which the change in membrane potential above could cause the firing of an action potential? Select all that apply. ___If the potential is counteracted by an IPSP. ___If the potential is strong enough to bring the axon hillock to threshold. ___If the neuron is in the relative refractory period. ___If the potential is supplemented by a simultaneous (or near-simultaneous) EPSP.
Which of the following describes a threshold potential? A brief reversal of the charge difference across a neuron's plasma membrane The membrane potential at which voltage-gated sodium channels in a neuron axon open, causing an action potential The membrane potential of a neuron at rest
When a neurotransmitter binds with receptors at the membrane, it may cause sodium channels to open. An inflow of sodium causes the membrane to partially depolarize and become less negatively charged. For example, the voltage might change from -70 mV to -65 mV. This partial depolarization of the dendrites and cell body acts as: an EPSP, exciting the cell and increasing the likelihood of action potentials. an IPSP, inhibiting the cell and reducing the likelihood of action potentials. none of these options; depolarization has no excitatory or inhibitory effect on a neuron. both an EPSP and and IPSP.
Which of the following is NOT true regarding the changes that occur during an action potential. Check All That Apply When stimulus is sufficient to cause the threshold potential to be reached, the area stimulated opens its voltage-gated sodium channels.When stimulus is sufficient to cause the threshold potential to be reached, the area stimulated opens its voltage-gated sodium channels. After threshold is reached, the sodium ions move into the cell via the Na+/K+ pump, the inside of the cell becomes momentarily positive.After threshold is reached, the sodium ions move into the cell via the Na+/K+ pump, the inside of the cell becomes momentarily positive. At almost the same time as Na+ channels are closing, voltage-gated potassium channels open, allowing an increased movement of potassium ions out of the cellAt almost the same time as Na+ channels are closing, voltage-gated potassium channels open, allowing an increased movement of potassium ions out of the cell The…
Which of the following combinations of spatial summation of postsynaptic potentials (PSP) would result in an action potential in a typical neuron? The voltage given for each PSP is measured as it reaches the axon hillock. Axon A EPSP 25 mV & axon B IPSP 10 mV Axon A IPSP 25 mV & axon B EPSP 10 mV Axon A IPSP 5 mV & axon B IPSP 5 mV Axon A EPSP 5 mV & axon B EPSP 5 mV
The membrane potential caused by differences in ions across the plasma membrane of an electrically excitable cell (when not stimulated) is called: action potential resting membrane potential graded potential local potential
The changes in membrane potential when a neuron is transmitting information is called ..... threshold action potential chemical potential resting potential
Which of the following can increase the likelihood of a neuron generating an action potential? tetrodotoxin (TTX) reducing the external concentration of K+ decreased diffusion of K+ through leak channels out of the neuron All of the above