Sensory Physiology

Question 1

The unique experience associated with a particular modality (like taste or smell) begins at what?

Answer 1

A receptor

Question 2

What is the initial interaction of the stimulus with the receptor?
What does that do?

Answer 2

Transduction- this is the transformation of physical energy into a neural signal

Question 3

What is an adequate stimulus?

For photoreceptors what would be an example of this?

Answer 3

It is the type of energy that given receptor is most sensitive to
Example- electromagnetic waves- photons, light

Question 4

Receptors have a limited sensitivity which results in what?

Answer 4

Sensory specificity

Question 5

The law of specific nerve energies is determined by what?

Answer 5

Its central connections

Question 6

Which two systems have receptor membranes immediately on the afferent neuron going to the CNS?

Answer 6

Somatosensory

Olfaction

Question 7

Which 4 systems go to receptor cells, which go to the afferent neuron?

Answer 7

Vision
Hearing
Balance
Taste

Question 8

The physical or direct interaction of a stimulus with the membrane protein does what? (termed direct transduction)

Answer 8

It opens an ion channel

Question 9

Molecular interaction of the stimulus occurs with what?

Or molecular G-protein transduction

Answer 9

A membrane protein, like a G protein

Question 10

What is a TRP channel?

Answer 10

It is a transient receptor potential. It is a cation channel that can pass Ca2+, which has a large variety of activating mechanisms

Question 11

T/F sometimes the relationship between stimulus intensity and neural/perceptual responses (action potentials) is linear?

Answer 11

True

Question 12

What is a receptive field?

Answer 12

It is what a receptor or neuron is sensitive to. IE light is a specific receptive field- can be heat and mechanoreceptors for example

Question 13

T/F- With a smaller spatial receptive field you have better spatial discrimination?

Answer 13

True

Question 14

What is lateral inhibition and what is its purpose?

Answer 14

One neuron receives the majority of a stimulation, the axon of that neuron sends out collateral axons that are interneurons, which are inhibitory to those around it so that the initial stimulus can be better localized

Question 15

What is presynaptic inhibition?

Answer 15

Where a hyperpolarized axon terminal leads to less Ca++ entry and less neurotransmitter release

Question 16

What is postsynaptic inhibition?

Answer 16

EPSPs and IPSPs interact: spatial and temporal summation

Question 17

T/F sensory maps are dynamic (plasticity)

Answer 17

True- there is greater discrimination in the left hand/fingers of stringed instrument players

Question 18

What happens in neurological injury?

Answer 18

collateral sprouting seeks to make up for the deficiencies caused by the lesion