Deck 6: Sensors I: Remote Sensing

Question 1

The process of converting an external signal to a neural signal is called _______________________.

Answer 1

sensory transduction

Question 2

The blind spot is

A) the area of the retina with the most photoreceptors
B) responsible for mostly color vision
C) responsible for mostly black and white vision
D) the region of the retina where axons leave the retina and enter the optic nerve

Answer 2

D

Question 3

Consider the anatomy of the eye. Place the following structures in order based on the sequence light would pass through them.
____ Retina
____ Lens
____ Cornea
____ Sclera
____ Choroid

Answer 3

3 , 2, 1 , 5, 4

Question 4

A degenerative disease that affects the retina might lead directly to which of the following problems?

A) Near-sightedness because of an inability to properly focus light entering the eye.
B) Far-sightedness because of an inability to properly focus light entering the eye.
C) Problems with light detection because of decreased photoreceptor function.
D) Impaired retinal circulation because of damage to the overlying blood vessels in the macula.

Question 5

Consider figure 6.3 In the text and perform the exercise. Why does the tip of the pencil seem to disappear?

A) Light reflected from the pencil tip is coming into contact only with photoreceptors in the fovea.
B) Light reflected from the pencil tip is coming into contact with blood vessels rather than photoreceptors.
C) No light is being reflected from the pencil tip.
D) Both eyes must be open to properly focus on an object at this distance.

Question 6

Which of the following is true of photoreceptors in the retina?

A) They contain opsin proteins that participate in visual signal transduction.
B) They respond to a light stimulus by depolarizing rather than hyperpolarizing.
C) They fire action potentials.
D) All of the above are true.

Question 7

Place the following events in the order they occur in the phototransduction cascade.
____ Light interacts with a molecule of retinal causing isomerization
____ Transducin is activated
____ An opsin molecule is activated
____ Phosphodiesterases are activated
____ cGMP is degraded
____ the photoreceptor hyperpolarizes
____ cyclic nucleotide-gated channels close
____ the amount of neurotransmitter released decreases

Question 8

What processes allow an eye to properly adjust to a dim environment?

A) the pupils dilate, allowing more light into the eye
B) photobleached retinal (the ligand for opsin proteins) is replaced with non-photobleached cis-retinal
C) high calcium concentrations inhibit the synthesis of cGMP
D) all of the above

Question 9

The visual system is sometimes described as having a very large "dynamic range" - that is, it is capable of responding to sensory stimuli over a large degree of stimulus (light) intensities. Why is this important? Decide whether this description is accurate, justify your response, and describe specific mechanisms that allow detection of light over such a broad range of intensities.

Question 10

Contrast the photoreceptor response with the "typical" response that a neuron might produce in response to stimulation as described in chapter 2. Which of the following is a difference?

A) In response to a stimulus, photoreceptors hyperpolarize.
B) Depolarization occurs because of ion channels that permit an influx of cations.
C) Intracellular calcium rises lead to the release of neurotransmitters in vesicles.
D) all of the above

Question 11

Construct a diagram of a rod photoreceptor synapsing with a rod bipolar cell that accounts for how a light stimulus ultimately results in the release of neurotransmitter in bipolar cells, despite the fact that photoreceptors are hyperpolarized by light.

Question 12

Consider the phototransduction cascade. Viagra (sildenafil) is a drug that inhibits phosphodiesterases. What might you expect would be a side effect of Viagra related to visual function?

A) Impaired ability of rhodopsin to detect photons
B) Impaired ability to degrade cGMP, thus limiting the cell's ability to hyperpolarize in response to light
C) Impaired ability for transducing to exchange GDP for GTP and thus activate second messengers
D) all of the above

Question 13

Analyze figure 6.6. In the text Which is true of this figure?

A) The yellow lines indicate the time points when light was shown on a salamander retina.
B) In the dark, the cell has a resting potential of -40mV.
C) An inward current flow exists when no light is present.
D) all of the above

Question 14

Analyze figure 6.7. In the text Which is true of this figure?

A) There are many more cones than rods in this section of retina.
B) Rod and cone morphology is quite similar; thus it is impossible to distinguish rods and cones using these staining techniques.
C) This figure shows that rods are hyperpolarized in response to a light stimulus.
D) None of the above are true.

Question 15

Which of the following is true about vision in dim light situations?

A) S-, M-, and L-cone opsins are not sensitive enough to detect dim light
B) Only photoreceptors containing rhodopsin are activated in very dim light
C) The peripheral retina is more sensitive to dim light than the fovea.
D) all of the above

Question 16

You are watching the stars at night, and you never seem to be looking at the right spot to catch the brightest meteors. Which of the following might explain this?

A) Your fovea contains mostly cones; thus you see dim light especially well when looking right at it.
B) Your peripheral retina contains more rods, which are more sensitive to dim light than cones; thus objects in your peripheral vision appear brighter in dim light situations.
C) Detection of light depends mostly on its color rather than intensity; thus cones play a larger role in detection of light in dim light situations.
D) all of the above

Question 17

Analyze figure 6.8. In the text This figure illustrates the fact that

A) there are more rods than cones in the retina
B) the blind spot contains no rods and no cones
C) mostly cones, and few rods, are found in the fovea
D) all of the above are true

Question 18

Which of the following is an accurate statement regarding color vision?

A) The ability to distinguish three distinct colors appears to have arisen multiple times over evolutionary history.
B) Color blindness results from missing or mutated cone opsin genes
C) In humans and some other primates, color vision may have been selected for because it more readily permits the identification of ripe fruit.
D) all of the above are true

Question 19

Analyze figure 6.9. In the text Which of the following is a true statement regarding this figure?

A) Only cones can detect light in the visible spectrum.
B) Only L-cones detect light of wavelength 600 nm.
C) Both S-cones and rods detect light that falls in the blue visible spectrum.
D) all of the above are true

Question 20

Which of the following is true regarding color vision in humans?

A) Normal vision requires functional copies of 3 different opsin genes.
B) Color-blindness is more common among males than females.
C) The M- and L-opsin genes are located on the X chromosome
D) all of the above are true

Question 21

Which of the following is a true statement regarding connections between cells in the retina?

A) Rods form synapses directly with Off Bipolar cells.
B) Cone bipolar cells synapse directly with retinal ganglion cells.
C) Rod bipolar cells synapse directly with retinal ganglion cells.
D) all of the above are true

Question 22

Construct a table, with "color vision/cones" on one side and "monochromatic vision/rods" on the other. Write down anatomical or functional features of the visual system associated with each heading.

Question 23

The visual system is able to detect very low levels of light. Outline at least 3 properties of photoreceptors and retinal connectivity that permit detection of very small amounts of light.

Question 24

Many rods synapse with biopolar cells, which in turn synapse with amacrine cells. These cells form connections with cone bipolar cells, which in turn synapse with retinal ganglion cells that form the optic nerve. This example illustrates the general principle known as

A) Convergence
B) Divergence
C) Trichromatic vision
D) None of the above

Question 25

Analyze figure 6.11 and the text dealing with retinoid recycling and the light path through the retina. What arguments does the author present that might argue against the idea that the retina is suboptimal in its design because of its "backward" arraignment?

A) The outer segments of photoreceptors require blood flow, and red blood cells would prevent light from reaching the retina if capillaries were in the light path.
B) Cones are more dense at the periphery of the fovea, which allows scattered light to be detected.
C) Specialized glial cells channel light toward the photoreceptors
D) All of the above

Question 26

Which of the following statements are correct regarding phototransduction and olfactory transduction?

A) Odorant molecules and light are both detected by G-protein coupled receptors.
B) Second messenger systems are used in both systems.
C) Cyclic nucleotide-gated ion channels are used in both systems to control cell membrane voltage
D) all of the above

Question 27

The phototransduction and olfactory transduction cascades both involve several intermediate steps between signal detection and the cellular response of photoreceptors or olfactory neurons. Propose an explanation for why you think these second messenger systems might be advantageous for the function of these sensory systems.

Question 28

Olfaction, the sense of smell, is used by an organism for which of the following purposes?

A) Detection of predators
B) Identification of food sources
C) Mate identification
D) all of the above

Question 29

Analyze the anatomic diagrams in figure 6.13. In the text Which of the following is a true statement?

A) The olfactory epithelium is superior to the bony (cribiform) plate adjacent to the olfactory bulb
B) Olfactory neurons synapse with cells in the glomeruli within the olfactory bulb
C) Odorant molecules are detected mitral cells in the olfactory bulb
D) All of the above are true statements.

Question 30

Which of the following is NOT associated with mucus in the olfactory epithelium?

A) Odorant molecules diffuse through it and contact cilia of olfactory neurons
B) It contains antibodies, antioxidants, and anti-inflammatory compounds
C) It contains odorant-binding proteins that facilitate diffusion of odorants
D) Olfactory neurons, like cortical neurons, are not generally replaced in adults

Question 31

What factors facilitate a dog's enhanced sense of smell (as compared with humans)?

A) Dogs have more olfactory receptor molecules than humans
B) Dogs have more olfactory neurons than humans
C) Dogs have specialized anatomy and behaviors that facilitate olfaction
D) All of the above are true

Question 32

Which of the following is true of olfactory receptor molecules?

A) They are G-protein coupled receptors
B) Humans have about as many opsin genes as olfactory receptor genes
C) Each olfactory receptor molecule only binds to a specific odorant molecule
D) All of the above are true

Question 33

Analyze figure b6.1. In the text What does this figure illustrate?

A) Females are able to better detect the smell of androstenone than males
B) The ability to smell androstenone is normally distributed in the population
C) There is no difference in sensitivity to androstenone between males and females
D) All of the above are true

Question 34

Place the following events in the order they occur in the olfactory cascade.
____ Odorant molecules interact with an olfactory receptor molecule
____ Adenylate cyclase is activated
____ G(olf) is activated
____ cAMP levels increase
____ the olfactory neuron depolarizes
____ cyclic nucleotide-gated channels open
____ the amount of neurotransmitter released increases

Question 35

Analyze figure 6.17. In the text What does this figure illustrate?

A) Olfactory neurons tend to project widely to many glomeruli in the olfactory bulb, as indicated by the blue stain.
B) All olfactory neurons express P2, as indicated by the blue stain.
C) Olfactory neurons that express P2 converge on just a few glomeruli, as indicated by the blue stain.
D) Olfactory neurons recognize only odorants that have P2 epitopes, as indicated by the blue stain.

Question 36

Do all humans perceive the world in the same way? What does this say about the physical world and our ability to perceive it? Justify your response with evidence from the sensory systems discussed in this chapter.

Question 37

Analyze figure 6.18. In the text What does this figure illustrate?

A) Each glomerulus responds to only one chemical compounds
B) Glomeruli only respond to compounds that contain carbon
C) Structurally similar compounds activate similar regions in the olfactory bulb
D) Decanal activates a more dorsal region of the olfactory bulb than pentanal.

Question 38

What is the role of mitral and granule cells in the olfactory bulb?

A) Each mitral cell receives input from only one glomerulus.
B) Granule cells release GABA onto mitral cells at inhibitory synapses.
C) Granule cells and mitral cells permit lateral inhibition among mitral cells.
D) All of the above.

Question 39

The loss of part or all of your sense of smell is known as ________________ .

Question 40

Which of the following is NOT true regarding the anatomy of the ear?

A) The pinna and ear canal direct sound to the tympanic membrane.
B) The bones of the middle ear transmit sound to the cochlea.
C) The stapes transmits sound by pressing on the tympanic membrane of the cochlea.
D) The ear drum will rupture when exposed to sounds greater than 140 dB.

Question 41

What is the primary function of the round window of the cochlea?

A) To transmit sound from the middle bones of the ear to the fluid filled cochlea.
B) To transmit sound from the outer ear to the bones of the middle ear.
C) To allow for displacement of the ear drum by relieving pressure in the middle ear.
D) To allow for displacement of the oval window by relieving pressure in the cochlea.

Question 42

Hair cell depolarization in the inner ear is normally the result of

A) deflection by "sound waves" (variations in air pressure)
B) deflection by fluid movement in the cochlea
C) action potentials arriving from the auditory nerve
D) none of the above are true

Question 43

Which of the following is NOT true regarding human audition?

A) movement of the tectorial membrane relative to the basilar membrane deflects stereocilia
B) the frequency of a sound influences how much a given region of the cochlea's basilar membrane will vibrate
C) hair cells are depolarized by GPCR receptors that are similar in structure to opsins odorant receptor molecules
D) all of the above are true

Question 44

After going to a concert, your hearing is muffled. What process may have been involved?

A) a protective increase in tension on muscles that allow movements of the ossicles (bones of the middle ear)
B) a protective increasing in the sensitivity of the cochlea to vibration
C) a protective closing of the tympanic membrane
D) a protective decrease in the potassium concentration of the endolymph
E) All of the above are true

Question 45

Some antibiotics interfere with the proper production and maintenance of the endolymph. These are said to be ototoxic. What would you suspect would be the result?

A) A decrease in the ability of ion channels in stereocilia to open and close
B) A decrease in hair cell function due to changes in the Nernst potentials of ionic species
C) A decrease in tip link length
D) A decrease in the ability of the ossicles to transmit sound from the tympanic membrane to the oval window

Question 46

Analyze figure 6.24. In the text Outline the evidence that there are mechanically-gated ion channels in stereocilia that are responsible for sensory transduction in the cochlea.

Question 47

Compared to you, a grandparent would be more likely to

A) not be able to detect loud sounds
B) not be able to detect high frequency sounds
C) not be able to detect low frequency sounds
D) not be able to detect sounds in the frequency range of the human voice

Question 48

You are studying a cell, and find that an action potential crosses the cells body and continues along the axon. This cell is most likely a

A) hair cell
B) spiral ganglion cell
C) photoreceptor
D) all of the above

Question 49

Consider the auditory system. Place the following structures in order based on the sequence that they are involved in auditory transduction.
____ cochlea
____ oval window
____ stapes
____ malleus
____ pinna
____ tympanic membrane

Question 50

Analyze figure 6.25. In the text What if NBQX had NOT caused the disappearance of EPSCs?

A) If no EPSCs were present, then glutamate is likely the neurotransmitter at this synapse
B) If no EPSCs were present, then neurotransmitters are not used at this synapse
C) If no EPSCs were present, then glutamate is likely not the neurotransmitter at this synpase
D) If no EPSCs were present, then this is not a ribbon synapse

Question 51

Contrast sensory transduction in hair cells with sensory transduction in olfaction. Which of the following is a true statement?

A) The ion responsible for depolarization in both systems is sodium.
B) In both systems, the cell is repolarized as cations are actively pumped out of the cell.
C) In both systems, potassium flows down its concentration gradient first into, and then out of, the cell.
D) None of the above are true statements.

Question 52

Adjacent regions of the cochlea detect similar frequencies. This is an example of a ________________ map in the nervous system.

Question 53

You have learned about somatotopic, tonotopic, and chemotopic mapping in the brain. Compose a short description of these ideas, and tell how these organizational schemes are similar and different from each other.

Question 54

Analyze figure b6.2.In the text If one electrode in a cochlear implant malfunctions and continuously stimulates the cochlea at varying intensities, what will be the result?

A) the wearer would repeatedly hear a tone that varies in volume
B) the wearer would repeatedly hear a tone of the same volume but with variable frequency
C) the wearer would hear repeated words or phrases
D) none of the above

Question 55

Adaptation to sensory stimuli is a feature of many sensory systems, and is evident in the way that the eyes adapt to dark rooms or how the ears adapt to loud sounds. Why is it beneficial for an organism to be able to adapt to extremes of stimuli intensity?

Question 56

Adaptation to sensory stimuli is a feature of many sensory systems, and is evident in the way that the eyes adapt to dark rooms or how the ears adapt to loud sounds. Why is it beneficial for an organism to be able to adapt to extremes of stimuli intensity?

Question 57

Imagine you are a scientist studying creatures that live in caves. Propose what types of sensory modalities that would be advantageous for animals that live in caves or similar environments and justify your answer. What types of senses would not be needed?

Question 58

Give 5 examples of sensory modalities that other organisms possess that humans do not.
_________________
_________________
_________________
_________________
_________________

Question 59

The text describes experiments where blind individuals receive sensory stimuli on their tongue that reflects their visual environment. Can you think of other types of sensory modalities that might be advantageous to represent as somatosensory stimuli? What types of abilities might you be able to confer on humans that were previously not possible?

Question 60

The text discusses "labeled lines" as an organizational scheme within the nervous system. Re-write the definition of a labeled line in your own words.