Sensory Physiology 315- Describe the phantom limb phenomenon and give a possible
explanation for its occurrence. - Explain the relationship between smell and taste. How are
these senses similar? How do they differ? - Explain how the vestibular apparatus provides information
about changes in the position of our body in space. - In a step-by-step manner, explain how vibrations of the oval
window lead to the production of nerve impulses. - Using the ideas of the place theory of pitch and the tonotopic
organization of the auditory cortex, explain how we perceive
different pitches of sounds. - Describe the sequence of changes that occur during
accommodation. Why is it more of a strain on the eyes to
look at a small nearby object than at large objects far away? - Describe the effects of light on the photoreceptors and
explain how these effects influence the bipolar cells. - Explain why images that fall on the fovea centralis are seen
more clearly than images that fall on the periphery of the
retina. Why are the “corners of the eyes” more sensitive to
light than the fovea? - Explain why rods provide only black-and-white vision. Include
a discussion of different types of color blindness in your answer. - Explain why green objects can be seen better at night than
objects of other colors. What effect does red light in a
darkroom have on a dark-adapted eye? - Describe the receptive fields of ganglion cells and explain
how the nature of these fields helps to improve visual acuity. - How many genes code for the sense of color vision? How
many for taste? How many for smell? What does this
information say about the level of integration required by the
brain for the perception of these senses? - Discuss the different functions of the pigment epithelium of
the retina, and describe the visual cycle of retinal. - What makes the lens of the eye clear? What happens when
cataracts form?
Test Your Analytical Ability
- You are firing your laser cannon from your position on the
bridge of your starship. You see the hostile enemy starship
explode, but you hear no accompanying sound. Can you
explain this? How do receptors for sight and hearing differ? - People with conduction deafness often speak quietly. By
contrast, people with sensorineural deafness tend to speak
louder than normal. Explain these differences. - Opioid drugs reduce the sensation of dull, persistent pain
but have little effect on the initial sharp pain of a noxious
stimulus (e.g., a pinprick). What do these different effects
imply? What conclusion can be drawn from the fact that
aspirin (a drug that inhibits the formation of prostaglandins)
functions as a pain reliever?
38. Compare the role of G-proteins in the senses of taste and
sight. What is the advantage of having G-proteins mediate
the effect of a stimulus on a receptor cell?
39. Discuss the role that inertia plays in the physiology of the
vestibular apparatus. Why is there no sensation of movement
in an airplane once it has achieved cruising speed?
40. Explain why menthol feels cold on the tongue and chili sauce
feels hot. What does this reveal about our perceptions of reality?
41. In order to see a dim star at night, it is better not to look
directly at it. If you see it from the “corner of your eye”
and then turn to look at it, it may disappear. Explain how
this occurs. Also, you can stare directly at an object in
daylight and continue seeing it, despite the bleaching of
photoreceptors. Explain how this is possible.
42. The pigment epithelial cells may undergo apoptosis in
response to the oxidative stress of free radicals (chapters 3
and 19). Explain what functions could be disturbed by a
damaged pigment epithelium, and relate this to the disease
of macular degeneration.
Test Your Quantitative Ability
Refer to figure 10.26 and use the figure reproduced below from
figure 10.42 to answer the following questions.ONLINE STUDY TOOLS
S (blue) cone M (green) cone L (red) cone400 500 600 700
Wavelength (nanometers)100500Relative sensitivity (%)- At which wavelength of light are the blue and green cones
equally stimulated? What color is this light? - Which cones are most sensitive to light at 600 nm? Which
are the least sensitive? - Which wavelength of light stimulates two cone systems to
the greatest degree? What color is this light? - Which wavelength of light stimulates all three of the cone
systems to the greatest degree? What color is this light?