Module D-01

Question 1

Which regions of cerebral cortex are sensory cortex areas found?

Answer 1

parietal, occipital, temporal, and insular lobes

Question 2

The process of converting the stimulus into a neuronal signal is called

Answer 2

Signal Transduction

Question 3

The process of interpretation of sensory input

Answer 3

Perception

Question 4

Behavioral responses that are triggered at SUB cortical regions

Answer 4

Reflexes

Question 5

What are the 4 sensory receptor classes ?

Answer 5

1) Mechanoreceptors
2) Thermoreceptors
3) Chemoreceptors
4) Photoreceptors

Question 6

Which sensory systems use Mechanoreceptors?

Answer 6

1) Somatosensory system
2) Vestibular system
3) Auditory system

Question 7

Which sensory systems use Thermoreceptors?

Answer 7

Somatosensory system ( uses all sensory receptors except photoreceptors)

Question 8

Which sensory systems use Chemoreceptors?

Answer 8

1) Somatosensory system
2) Olfactory system
3) Gustatory system

Question 9

Which sensory systems use Photoreceptors?

Answer 9

Visual system

Question 10

Perikaryon aka

Answer 10

soma

Question 11

Which are the 6 sensory systems?

Answer 11

1) Somatosensory system
2) Vestibular system
3) Auditory system
4) )Olfactory system
5) Gustatory system
6) Visual system

Question 12

Auditory hair cell is an example of a sensory _________, not a sensory __________ , therefore produces no _________

Answer 12

Receptor cell ;receptor neuron; Action Potentials

Question 13

What 3 process occur in a sensory receptor NEURON:

Answer 13

1) Graded Receptor potential at the Transduction site
2) Action Potential in the axon
3) transmitter release at the terminal

Question 14

__________ and ________ varies in Graded receptor potentials whereas the only variation in Action Potentials is the _________

Answer 14

Duration ; Intensity ; Frequency ( number of APs per time)

Question 15

Area of axon where APs are generated once reaches threshold

Answer 15

Trigger zone (IIZ)

Question 16

Trigger zone is sensory receptor neurons:

Answer 16

close to transduction site not at axon hillock ( motor neurons)

Question 17

What type of cells are receptor cells like hair cells

Answer 17

Specialized Epithelial cells

Question 18

What processes take place in a sensory receptor cell?

Answer 18

1) Graded Receptor Potential at the apical (transduction) site
2) Transmitter release at the base of the cell onto afferent fiber

Question 19

What 4 Attributes are used to characterize a Sensory Stimulus?

Answer 19

1) Modality- type of stimulus
2) Intensity- amplitude
3) Duration- time
4) Location

Question 20

How is stimulus Modality encoded in sensory systems?

Answer 20

Labelled line code

Question 21

How is stimulus Intensity encoded in sensory systems?

Answer 21

Receptor potentials: amplitude ; low intensity stimuli cause small graded potentials
Action potentials: frequency code; HIgh intensity stimuli=> high receptor potentials above threshold=> high freq of APs

Population code: the high the intensity of the stimulus can activate more individual axons

Question 22

How is stimulus Duration encoded in sensory systems?

Answer 22

Receptor adaptation rate:
Slowly adapting receptors: active for the whole stimulus duration ; remain depolarized and produce increased rates of action potentials for the whole duration of the stimulus

Rapidly adapting receptors: active during changes (on/off)
firing rate may increase during the onset of the stimulus, it may return to the basal rate during the duration of the stimulus, and the offset of the stimulus might cause a short drop in firing rate

Question 23

How is stimulus Location encoded in sensory systems?

Answer 23

Receptive fields

Question 24

What is the difference btw types of stimuli that slow and rapidly adapting receptors are more sensitive to?

Answer 24

-slowly adapting receptors - better in constantly monitoring
levels of stimulation
-Rapidly adapting receptors- most sensitive to
changes, not to constant stimulation

Question 25

What is a receptive field?

Answer 25

area where responses can be induced in a certain neuron within a sensory pathway

Question 26

What are the Three Basic Wiring Mechanisms of Sensory

Systems?

Answer 26

1) Convergence
2) Divergence
3) Lateral Inhibition

Question 27

What is convergence?

Answer 27

When a second order neuron in a sensory pathway receives input from more than one first order neurons

Question 28

What info does convergence in neurons give?

Answer 28

Where the information is coming from

Question 29

What is divergence?

Answer 29

signal from one first order neuron diverges by sending axon collaterals to more than one subsequent neuron

Question 30

Purpose of Divergence

Answer 30

tells us where the information is going to

Question 31

Tor F—-Convergence , divergence and lateral inhibition are mutually exculsive

Answer 31

False , they may coexist

Question 32

What does Lateral inhibition help with?

Answer 32

• Two point discrimination

- Perception of a single stimulus against its background