During precortical processing of sensory input, some features of stimuli are accentuated and others are suppressed through ____.
a. precortical filtering
b. desensitization
c. cortical damping
d. medial inhibition
e. lateral inhibition
(
Question 2) If neuron X is repeatedly stimulating neuron Z with an excitatory neurotransmitter, then
a. several simultaneous action potentials might be initiated on neuron Z
b. the membrane potential on neuron Z would increase
c. spatial summation would be occurring on neuron Z
d. the postsynaptic neuron in this situation would have to reach threshold voltage
e. none of the above would have to occur
(
Question 3) What kind of nerves carries subconscious input information?
a. sensory afferent
b. sensory efferent
c. visceral afferent
d. visceral efferent
e. peripheral motor
(
Question 4) The trigger zone of a neuron
a. is located at the axon hillock
b. is located in the axon terminal
c. contains only chemically gated channels
d. conducts graded potentials to the axon
e. causes action potentials to move toward the cell body and dendrites
(
Question 5) How many tactile mechanoreceptors are estimated to be in a typical fingertip?
a. 17,000
b. 5,000
c. 1,700
d. 500
e. 170
(
Question 6) The relative refractory period occurs after the action potential is complete because of
a. the lingering inactivation of the voltage-gated Na+ channels
b. the slowness of the voltage-gated K+ channels
c. the action of the sodium-potassium pumps
d. both a and b
e. both b and c
(
Question 7) What kind of tactile receptor is stimulated by light, sustained touch?
a. Pacinian corpuscles
b. Merkel's discs
c. Ruffini endings
d. Meissner's corpuscles
e. dermatomes
(
Question 8) The period following an action potential during which a membrane cannot experience another action potential
a. is the absolute refractory period
b. occurs during the time after the Na+ gates have opened until they are restored to their closed but capable of opening state
c. prevents the action potential from spreading back over the part of the membrane where the impulse has just passed
d. includes the time when Na+ gates are in a closed and not capable of opening state
e. includes all of the above
(
Question 9) What are rapidly adapting receptors called?
a. phasic
b. tonic
c. clonic
d. depolarizing
e. responsive
(
Question 10) Which statement is true about the absolute refractory period?
a. It ensures that action potentials move in only one direction along a nerve fiber.
b. It is the period when the membrane can undergo another action potential, but only if the stimulus is strong enough.
c. It is the time during an action potential when voltage-gated Na+ channels are in their closed but capable of opening conformation.
d. places a lower limit on the frequency with which a neuron can conduct action potentials.
e. All of the above statements are true.
Quick Reply
