The upper limit of a neuron's firing rate is estimated to be _____ impulses per second.
A) 20
B) 100
C) 800
D) 4400
As stimulus intensity is increased, recording from a single neuron shows that _____.
A) the amplitude of the action potential increases
B) the amplitude of the action potential decreases
C) the amplitude of the action potential may increase or decrease, depending on the stimulus
D) the rate of firing of the nerve fiber increases
Which of the following statements best defines the propagated response?
A) Once a response is triggered, the response travels the length of the axon without decreasing in amplitude.
B) Once a response is triggered, the response gradually increases in amplitude as it travels down the length of the axon.
C) The response increases the positive charge of the chlorine ions throughout the length of the axon.
D) The number of negative potassium ions increase the closer the impulse is to the dendrites.
The difference in charge between the inside and the outside of the nerve fiber when the nerve is at rest is _____ mV.
A) -70
B) -10
C) 0
D) +19
The three major parts of a neuron are _____.
A) dendrites, cell body, and axon
B) axon, nerve fiber, and receptor
C) receptor, transmitter, and median
D) receptor, dendrites, and conductor
There are ____ different cone receptors, each with different absorption spectra.
A) 2
B) 3
C) 4
D) 7
The Purkinje shift _____.
A) occurs when reds appear brighter than blues in well-lit conditions, but blues appear brighter than reds in dim conditions
B) occurs when blues appear brighter than reds in well-lit conditions, but blues appear brighter than reds in dim conditions
C) occurs when details that are easily seen in well-lit conditions become more difficult to see in low-light conditions
D) demonstrates the importance of eye movements in visual pigment regeneration
The peak in the spectral sensitivity curve is about _____ for the rods, and about _____ for the cones.
A) 700 nm; 400 nm
B) 450 nm; 800 nm
C) 500 nm; 560 nm
D) 600 nm; 450 nm
Cone spectral sensitivity is measured by having the observer _____.
A) look up and blink
B) look straight forward without blinking
C) look directly into a light
D) look to the side of a flashing light
Rushton demonstrated that the physiological mechanism behind dark adaptation is _____.
A) visual pigment regeneration
B) the enzyme cascade
C) modular organization
D) photon remission
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