Neuro - Quiz 3

Which of the following is a potential reason why different people perceive the same odorant differently? a) different people likely have different numbers of olfactory receptor neurons b) different people likely express different odorant receptor molecules c) people have different sensitivities across the carbon chain axis of the olfactory system

b) different people likely express different odorant receptor molecules

What is the main function of the three little bones of the middle ear? a) to efficiently code the frequency of incoming sound waves b) to efficiently transfer sound pressure waves from air to liquid c) to efficiently transfer sound pressure waves from liquid to air d) to support the weight of the cochlea in the inner ear

b) to efficiently transfer sound pressure waves from air to liquid

True or false? Cone photoreceptors are more densely packed in the fovea than rod photoreceptors in the surrounding retina.

true

What most directly causes the hyperpolarization of a photoreceptor in response to light? a) activation of phosphodiesterase by transducin, which reduces cGMP levels b) rhodopsin activation of a photoreceptor K+ channel c) activation of guanylyl cyclase by transducin, which increases cGMP levels d) increased GABA neurotransmission from off center bipolar cells

a) activation of phosphodiesterase by transducin, which reduces cGMP levels

In which of the following ways are sound frequencies coded within the cochlea? a) hair cells at the base of the cochlea respond to high frequencies whereas cells near the apex respond to low frequencies b) different frequencies result in the release of different neurotransmitters c) outer hair cells respond to low frequencies whereas inner hair cells respond to high frequencies d) hair cells at the base of the cochlea respond to low frequencies whereas cells near the apex respond to high frequencies

a) hair cells at the base of the cochlea respond to high frequencies whereas cells near the apex respond to low frequencies

In which region(s) does neurogenesis occur within the adult nervous system, in mammals? a) hippocampus b) olfactory bulb c) amygdala d) entorhinal cortex e) olfactory epithelium f) hypothalamas

a) hippocampus b) olfactory bulb e) olfactory epithelium

Which choice best describes the cyclic GMP gated ion channels in the visual system? a) in the dark, there is a high concentration of cGMP, Na+ flows in and the cell depolarizes b) in the dark, there is a low concentration of cGMP, Na+ flows in and the cell depolarizes c) in the light, there is a low concentration of cGMP, Na+ flows in and the cell depolarizes d) in the light, there is a high concentration of cGMP, Na+ flows in and the cell depolarizes

a) in the dark, there is a high concentration of cGMP, Na+ flows in and the cell depolarizes

Which axon is likely to maintain connection with a postsynaptic cell during synaptic development? a) the one that is the most active, therefore signaling functional connectivity b) the one that is the least active, therefore preserving the most energy in the form of ATP c) the one that most recently reaches the target after cell maturity (latest contact supersedes previous contacts) d) the one that reaches the target first (first contact supersedes later contacts)

a) the one that is the most active, therefore signaling functional connectivity

Which of the following is a key difference between transduction in taste receptors detecting bitter, and olfactory receptor neurons detecting floral scents? a) bitter taste receptors use g-protein linked receptor molecules while olfactory neurons use ionotropic receptor molecules b) bitter taste receptors depolarize while olfactory neurons hyperpolarize in response to chemicals c) bitter taste receptors use phospholipase C while olfactory neurons use adenylyl cyclase d) bitter taste receptors hyperpolarize while olfactory neurons depolarize in response to chemicals

c) bitter taste receptors use phospholipase C while olfactory neurons use adenylyl cyclase

Electrophysiological recordings of auditory cells reveal a much higher sensitivity to specific sound frequencies than has been expected from simple models of the cochlea. This enhanced sensitivity is most likely due to... a) a much higher elasticity of the basilar membrane than what is usually modeled b) all of the answers are correct c) the presence of active amplification within the cochlea d) the activity of the tectorial as well as the basilar membrane

c) the presence of active amplification within the cochlea

Which of the following statements about the center-surround receptive field of an off-center retinal ganglion cell is true? a) the strongest stimulus for it is light in its center and darkness in its surround b) it is excited by light in the center and also excited by light in its surround c) the strongest stimulus for it is darkness in its center and light in its surround d) it is inhibited by light in the center and also inhibited by light in the surround

c) the strongest stimulus for it is darkness in its center and light in its surround

What is one hypothesized reason for why olfaction is more closely linked to emotion than other senses? a) olfaction is more likely to sense danger in the environment than other sense b) it is an especially acute sense in humans c) unlike most other senses, olfaction has a more direct connection to the cortex, amygdala, hippocampus, and hypothalamus d) the olfactory bulb has an unusually dense connection to the hypothalamus

c) unlike most other senses, olfaction has a more direct connection to the cortex, amygdala, hippocampus, and hypothalamus

Which of the following best describes the glomerular code for odor detection and discrimination? a) a specific olfactory receptor molecule binds a wide variety of odorants and activates glomeruli b) a specific odorant activates a small or large proportion of glomeruli in the olfactory bulb, in relation to the importance of that scent to the animal c) a specific odorant activates most of the glomeruli in the olfactory bulb to a specific extent, causing an action potential firing rate in relation to the importance of that scent to the animal d) a specific odorant activates only a small set of glomeruli

d) a specific odorant activates only a small set of glomeruli

Which sensory system responds with a hyperpolarization as part of its sensory transduction mechanism? a) pheromone system b) auditory system c) vestibular system d) visual system

d) visual system

True or false? If humans have pheromone perception, it would likely be through the vomeronasal organ, as it is in most other animals.

false