AMP Exam 2

At the normal resting membrane potential of a typical neuron, it's sodium-potassium exchange pump transports

3 intercellular sodium ions for 2 extra cellular potassium ions

The all-or-nothing principle states

All stimuli great enough to bring the membrane to threshold will produce identical action potentials

To ion that triggers the release of acetylcholine, a neurotransmitter, into the synaptic cleft is

Calcium

IPSPs (inhibitory postsynaptic potentials) A) are local depolarizations. B) are local hyperpolarizations. C) increase membrane permeability to sodium ions. D) block the efflux of potassium ions. E) block the efflux of calcium ions.

E

How would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactivate?

It would last indefinitely.

If the chemically gated sodium channels in the postsynaptic membrane were completely blocked

Synaptic transmission would fail

If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur except

The intercellular concentration of potassium ions will increase

Which of the following types of nerve fiber processes the fastest speed of impulse propagation

Type A

In which of the following would the rate of impulse conduction be the greatest

a myelinated fiber of 10-µm diameter

Open or close in response to binding specific molecules

chemically gated channels

A postsynaptic neuron will have an excitatory postsynaptic potential (EPSP) when

chemically regulated sodium channels are open and sodium is diffusing into the cell.

Opening of sodium channels in the axon membrane causes

depolarization

A threshold stimulus is the

depolarization necessary to cause an action potential

A neuron that receives neurotransmitter from another neuron is called

postsynaptic neuron

Rapid impulse conduction from "node" to "node" is called

saltatory propagation

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated

spatial summation

When potassium channels open and the ions diffuse through the membrane,

the inside of the membrane will become more negative