What information would best help you distinguish what type of sensation a sensory neuron transmits?

Question

A.  the rate of action potential firing
B.  the proteins it expresses most abundantly
C.  the part of the brain it transmits signals to
D.  the amplitude of action potentials
E.  the diameter of the axon

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

Gather Content
What do you already know about sensory neurons? What other information is related to the question?

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

C.  the part of the brain it transmits signals to

Clarify Question
What is the key concept addressed by the question?
        · How to determine sensory modality.
What type of thinking is required?
            o This question is asking you to weight and judge, or evaluate, traits that might vary by sensory modality.

Gather Content
What do you already know about sensory neurons? What other information is related to the question?
        · You already know that sensory neurons either detect stimuli or are connected to sensory receptors that do. Axons from sensory neurons then enter the dorsal roots of the spinal cord before sending their signals on to the brain. The area of the brain that the signals get sent to depends upon which sensory system is involved. Visual information gets sent to the visual cortex in the occipital lobe. Somatosensory information gets processed in the parietal cortex. Hearing is processed in the temporal lobe. Commonalities of all sensory neurons are that they all fire action potentials and the frequency of action potentials codes for intensity of sensory stimulation.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Let us evaluate each answer individually. First, rate of action potential firing encodes the strength of sensory stimulation in all sensory modalities, so it would not be a good means of distinguishing between different types of sensation. Second, the proteins that are expressed most abundantly.It is true that different sensory systems utilize different neurotransmitters and thus may express proteins for different receptors, but there is also an overlap between neurotransmitters utilized, and proteins expressed, in different sensory systems so you could not distinguish between sensory modalities using this alone. The part of the brain that a sensory neuron sends signals to is unique for each sensory system, so this is the correct answer. The amplitude of action potentials do not vary by sensory system. It is true that some sensory systems have sensory neurons that differ in morphology. For example, some pain fibers are thin and unmyelinated while other somatosensory neurons are myelinated and have a thicker diameter. Thus, it would be hard to determine if a sensory neuron belonged to the somatosensory system by the diameter of the axon alone.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o Answering this question correctly depended on your ability to weigh and  judge, or evaluate, which different characteristics of sensory neurons. If you got an incorrect answer, did you remember that different regions of the brain process different sensory information, or that all sensory systems use frequency coding? Did you have trouble weighing the merits of differential protein expression relative to unique parts of the brain for different sensory systems to determine the correct answer?