230
Chapter 7
Chapter 7 Test Questions
(Answers appear in Appendix A.)
1. Choose the TRUE statement:
a. The modality of energy a given sensory receptor responds to
in normal functioning is known as the “adequate stimulus”
for that receptor.
b. Receptor potentials are “all-or-none”; that is, they have the
same magnitude regardless of the strength of the stimulus.
c. When the frequency of action potentials along sensory
neurons is constant as long as a stimulus continues, it is
called “adaptation.”
d. When sensory units have large receptive fi elds, the acuity of
perception is greater.
e. The “modality” refers to the intensity of a given stimulus.
2. Using a single intracellular recording electrode, in what part
of a sensory neuron could you simultaneously record both
receptor potentials and action potentials?
a. in the cell body
b. at the node of Ranvier nearest the peripheral end
c. at the receptor membrane where the stimulus occurs
d. at the central axon terminals within the CNS
e. there is no single point where both can be measured
3. Which best describes “lateral inhibition” in sensory processing?
a. Presynaptic axo-axonal synapses reduce neurotransmitter
release at excitatory synapses.
b. When a stimulus is maintained for a long time, action
potentials from sensory receptors decrease in frequency with
time.
c. Descending inputs from the brainstem inhibit afferent pain
pathways in the spinal cord.
d. Inhibitory interneurons decrease action potentials from
receptors at the periphery of a stimulated region.
e. Receptor potentials increase in magnitude with the strength
of a stimulus.
4. What region of the brain contains the primary visual cortex?
a. the occipital lobe
b. the frontal lobe
c. the temporal lobe
d. the somatosensory cortex
e. the parietal lobe association area
5. Which type of receptor does NOT encode a somatic sensation?
a. muscle spindle stretch receptor
b. nociceptor
c. Pacinian corpuscle
d. thermoreceptor
e. cochlear hair cell
6. Which best describes the vision of a person with uncorrected
nearsightedness?
a. The eyeball is too long; far objects focus on the retina when
the ciliary muscle contracts.
b. The eyeball is too long; near objects focus on the retina
when the ciliary muscle is relaxed.
c. The eyeball is too long; near objects cannot be focused on
the retina.
d. The eyeball is too short; far objects cannot be focused on
the retina.
e. The eyeball is too short; near objects focus on the retina
when the ciliary muscle is relaxed.
7. If a patient suffers a stroke that destroys the optic tract on the
right side of the brain, which of the following visual defects will
result?
a. Complete blindness will result.
b. There will be no vision in the left eye, but vision will be
normal in the right eye.
c. The patient will not perceive images of objects striking the
left half of the retina in the left eye.
d. The patient will not perceive images of objects striking the
right half of the retina in the right eye.
e. Neither eye will perceive objects in the right side of the
patient’s fi eld of view.
8. Which correctly describes a step in auditory signal
transduction?
a. Displacement of the basilar membrane with respect to the
tectorial membrane stimulates stereocilia on the hair cells.
b. Pressure waves on the oval window cause vibrations of the
malleus, which are transferred via the stapes to the round
window.
c. Movement of the stapes causes oscillations in the tympanic
membrane, which is in contact with the endolymph.
d. Oscillations of the stapes against the oval window set up
pressure waves in the semicircular canals.
e. The malleus, incus, and stapes are found in the inner ear,
within the cochlea.
9. A standing subject looking over her left shoulder suddenly
rotates her head to look over her right shoulder. How does the
vestibular system detect this motion?
a. The utricle goes from a vertical to a horizontal position, and
otoliths stimulate stereocilia.
b. Stretch receptors in neck muscles send action potentials to
the vestibular apparatus, which relays them to the brain.
c. Fluid within the semicircular canals remains stationary,
bending the cupula and stereocilia as the head rotates.
d. The movement causes endolymph in the cochlea to rotate
from right to left, stimulating inner hair cells.
e. Counter-rotation of the aqueous humor activates a
nystagmus response.
10. Which category of taste receptor cells does MSG (monosodium
glutamate) most strongly stimulate?
a. salty
b. bitter
c. sweet
d. umami
e. sour
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