7.1 - 7.2

Question 1

If sensory information reaches consciousness, it can be called a ___.

Answer 1

sensation

Question 2

The chemical or energy that results in the activation of a sensory receptor is known as a(n) ___.

Answer 2

stimulus

Question 3

Overall, the process by which a stimulus is transformed into an electrical response is known as ___ ___.

Answer 3

sensory transduction

Question 4

A graded change in membrane voltage occurring in sensory cells in response to a stimulus is called a ___.

Answer 4

receptor potential

Question 5

What is demonstrated by the figure of the stimulation of an afferent neuron with a receptor ending (figure 7.2)?

Answer 5

• Receptor potentials are graded with stimulus size.
• Action potential frequency increases with stimulus size.

Question 6

T/F: All sensory signals are consciously perceived.

Answer 6

F

Question 7

Besides modality, what other types of information are encoded by sensory receptors?

Answer 7

Location and intensity

Question 8

In sensory physiology, the term “adequate stimulus” means ___.

Answer 8

the type of stimulus (modality) to which a particular receptor is most suited to respond

Question 9

In general, receptors of a given sensory unit ___.

Answer 9

all respond to the same modality

Question 10

___ is the process that converts energy from a physical stimulation into nerve impulses, which are then transmitted to the appropriate parts of the brain.

Answer 10

Sensory transduction

Question 11

Receptor potentials that occur in sensory neurons are examples of ___ potentials.

Answer 11

graded

Question 12

Variations in stimulus intensity can be due to which of the following factors?

Answer 12

• Frequency of sensory nerve fiber firing
• Magnitude of receptor potentials
• Recruitment of different numbers of afferent neurons

Question 13

In myelinated sensory neurons, the site of action potential generation in response to excitatory stimulation is usually at the first ___ of ___.

Answer 13

node of Ranvier

Question 14

The location of a stimulus is encoded mainly by ___.

Answer 14

which neurons deliver action potentials to the brain

Question 15

What three main characteristics of a stimulus are encoded by sensory receptors?

Answer 15

stimulus…
- modality
- intensity
- location

Question 16

Sensory acuity is the ___.

Answer 16

precision with which we can locate and discern one stimulus from an adjacent one

Question 17

The type of stimulus, such as whether it is heat, cold, sound or pressure, is known as the stimulus ___.

Answer 17

modality

Question 18

To test sensory acuity of an area of the body, one can apply two sharp objects to see if discrimination of the points is possible. Areas of the body with the highest numbers of sensory receptors, and the smallest receptive fields, will have the ___ sensory acuity.

Answer 18

highest

Question 19

The conversion of stimulus energies such as pressure, light, or chemical concentration into electrical signals is referred to as sensory ___.

Answer 19

transduction

Question 20

Which of the following does NOT influence the encoding of stimulus intensity?

Answer 20

duration of the stimulus

Question 21

T/F: The location of all stimuli is interpreted from the place on our body where the stimulus was actually applied.

Answer 21

F

Question 22

Which region of the body would have the greatest sensory acuity?

Answer 22

A region with large numbers of small sensory units

Question 23

When receptive fields of adjacent sensory neurons responding to the same modality overlap, it ___ sensory activity.

Answer 23

increases

Question 24

Stimulus intensity is coded by (1) the frequency of ___ of individual sensory units and (2) by the number of sensory units activated. This “calling in” of receptors on additional afferent neurons is known as ___.

Answer 24

firing; recruitment

Question 25

The specific nerve fibers which send the signal to the brain determines signal ___.

Answer 25

location

Question 26

Which is true about the frequency of action potentials propagated by sensory neurons A, B, and C, and the ability to localize the stimulus? (B overlaps A & C, but has most coverage of the stimulus)

Answer 26

The frequency will be highest in neuron B, helping to localize the stimulus.