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