Sensory Receptor Mechanisms

Question 1

What are the 5 Special Senses

Answer 1

Smell
Taste
Hearing
Balance
Vision

Question 2

How are sensory systems classified by signal origin?

Answer 2

Exteroreceptors (Info about world)

Interoreceptors (Info about internal environ)

Question 3

What is sensory modality?

Answer 3

The differentiation between one sense and another

Question 4

How are sensory systems classified by stimulus energy?

Answer 4

Different receptors respond optimally to specific types of energy (Adequate stimulus)

Question 5

What is the primary function of a sensory receptor?

Answer 5

Transduction of sensory stimulus energy to an electrical signal

Question 6

What are the 4 steps in the initial transduction sequence?

Answer 6

Stimulus
Membrane Conductance Change
Generator Potential
Action Potential

Question 7

Which of the 4 steps is a graded potential?

Answer 7

Generator Potential

Question 8

what is always true about generator potentials?

Answer 8

They are always depolarizing

Question 9

What are the 2 types of graded potentials?

Answer 9

Generator

Receptor

Question 10

What makes up a sensory unit?

Answer 10

Sensory Nerve and Receptor

Question 11

How do the Na ion channels open in a Pacinian Corpuscle?

Answer 11

Compression

Question 12

What kind of potential is generated by the compression?

Answer 12

Generator

Question 13

Where are Pacinian corpuscles found?

Answer 13

Skin and CT

Question 14

What happens when the Generator potential reaches threshold at the 1st node of ranvier?

Answer 14

An AP is fired

Question 15

Does a taste cell create a generator potential or a receptor potential?

Answer 15

Receptor

Question 16

How is the AP in the afferent nerve stimulated in a taste cell?

Answer 16

An adequate stimulus produces a receptor potential.

This releases transmitter on to the afferent nerve terminal

Question 17

What kind of information must be coded into the electrical signals to the CNS?

Answer 17

Phasic/Tonic Response
Intensity of Stim
Modality
Location
Sensory Acuity

Question 18

Describe Phasic Receptors

Answer 18

Adapt rapidly to stim and are quickly ready to register onset of new stimuli

Question 19

Describe Tonic Receptors

Answer 19

Do not adapt to stim at all (or slowly) and are designed to signal ongoing stimulus intensity

Question 20

Which stimuli receptor GP lasts for the entire duration of the stimulus?

Answer 20

Tonic

Question 21

How is stimuli intensity coded?

Answer 21

Frequency: Larger GPs make Higher frequency APs

Question 22

What is the relationship between GP amplitude and AP frequency

Answer 22

Directly proportional

Question 23

What is the relationship between stimulus strength and GP amplitude?

Answer 23

Non-linear

Question 24

How is population coded?

Answer 24

More pressure will activate more pacinian corpuscles

Question 25

How does the CNS interpret for Stimulus Strength?

Answer 25

Frequency code from Stim Intensity | Population Code

Question 26

How does the brain determine stimulus modality?

Answer 26

Anatomically by location of signal in the cortex

Question 27

How do we know where a stimulus is located?

Answer 27

Map of the brain that matches the location of the nerve sending the signal Size of the receptive fields for the involved afferent nerves.

Question 28

What is the receptive field?

Answer 28

Area over which a stimulus elicits a response in the sensory neuron. Smaller fields mean higher sensory acuity

Question 29

Which is the 1st order neuron?

Answer 29

Receptor to Dorsal Root Ganglion