Quiz- Action Potential

a. the resting membrane potential has been reestablished

A second nerve impulse cannot be generated until____ a. the resting membrane potential has been reestablished b. all sodium gates a re closed c. all sodium is plumped out of the cell d. the Na ions have been pumped back into the cell

The influx of sodium causes adjacent areas to reach threshold

An action potential is regarded as an example of a positive feedback. Which of the following examples below best illustrate the positive feedback aspect of an action potential? a. The influx of sodium causes adjacent areas to reach threshold b. voltage gated potassium ion channels open slowly and remain open long enough to cause hyperpolarization c. The sodium potassium pump consistently moves ions as long as ATP is available and regardless of membrane potential changes. d. potassium permeability is about 25 times greater than sodium ions.

a. voltage-gated potassium channels

Immediately after an action potential has peaked, which of the following channels will open? a. voltage-gated potassium channels b. voltage-gated calcium channels c. voltage- gated sodium channels

a. True

The action potential is caused by permeability changes in the plasma membrane.

a. depolarization

opening of voltage-gated sodium channels in the membrane of a neuron results in a. depolarization b. increased negative charge inside the membrane c. hyperpolarization d. myelination

d. -70mV

The resting potential of a neuron is a. +10 mV b. -10mV c. 0mV d. -70mV

a. the voltage gated potassium ion channels remain open longer to hyperpolarize the axon membrane

During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due the fact that______. a. the voltage gated potassium ion channels remain open longer to hyperpolarize the axon membrane b. the sodium potassium pump will stop working during relative refractory. c. the membrane is now impermeable to all ions d. the inactivation gates on voltage gated sodium ion channels are closed.

d. hyperpolarization

The condition in which voltage gated channels are slow to cause and thus results in a more negative condition than the original resting state of the cell is called a. summation b. refraction c. depolarization d. hyperpolarization

a. voltage-gated channels

Which ion channels open in response to a change in membrane potential and participates in the generation and conduction of action potentials? a. voltage-gated channels b. mechanically- gated channels c. leakage channels

d. it can be inhibitory or excitatory.

Which of the following correctly describes a graded potential? a. it is initiated by voltage changes in the membrane b. it has a depolarization, repolarization, and hyperpolarization phase. c. it travels long distances d. it can be inhibitory or excitatory.