Sensory Mechanism

Question 1

Sensations

Answer 1

• triggered by sensory stimuli
• travel to brain as action potentials (APs) via sensory pathways
• awareness of sensory stimuli

Question 2

Sensations

Answer 2

• triggered by sensory stimuli
• travel to brain as action potentials (APs) via sensory pathways
• awareness of sensory stimuli

Question 3

Sensation problems

Answer 3

• conversion of stimulus energy into a neuronal signal
• encoding information about stimulus
• interpretation of information

Question 4

Functions of the nervous system

Answer 4

rapid communication

• information processing

Question 5

Sensory input

Answer 5

external and internal information from sensory receptors

Question 6

Integration

Answer 6

• interpretation of input

* association of input with responses

Question 7

Afferent neurons

Answer 7

from periphery to central nervous system (CNS)

Question 8

Motor output

Answer 8

signals from integration centre(s) to effector cells

Question 9

Problem : conversion of stimulus energy into a neuronal signal

Answer 9

Solution : Transduction =
stimulus → sensory receptors → change in receptor membrane
permeability → receptor potential (graded change in membrane
potential)

-amplification (e.g. by activation of a cascade) and sensory
adaptation (continued stimulation → ↓ responsiveness)

• transmission:
  • if receptor = sensory neuron: it conducts APs to CNS
  • if receptor ≠ sensory neuron: sensory neuron generates APs

Question 10

Problem : P encoding information about stimulus

Answer 10

Solution : S type of stimulus
• type of activated receptor
S intensity
• number of activated receptors
• frequency of action potentials
S location
• location of activated receptors
• timing of receptor activation (for sound and smell)
S duration
• pattern of action potentials

Question 11

Receptor types

Answer 11

-chemoreceptors
• mechanoreceptors
• thermoreceptors
• nociceptors
• electromagnetic receptors

Question 12

Problem: interpretation of information

Answer 12

Solution : S process and integrate sensory information, starting in the
sensory pathways and culminating in the brain
S hierarchical and parallel processing of information
S different parts of the brain process different perceptions
S incorporation of information from different modalities in
higher association centres

Question 13

Motor output

Answer 13

signals from integration centre(s) to effector cells

Question 14

Efferent neurons

Answer 14

form CNS to the periphery

Question 15

Problem : conversion of stimulus energy into a neuronal signal

Answer 15

Solution : Transduction =
stimulus → sensory receptors → change in receptor membrane
permeability → receptor potential (graded change in membrane
potential)

-amplification (e.g. by activation of a cascade) and sensory
adaptation (continued stimulation → ↓ responsiveness)

• transmission:
  • if receptor = sensory neuron: it conducts APs to CNS
  • if receptor ≠ sensory neuron: sensory neuron generates APs

Question 16

Problem : P encoding information about stimulus

Answer 16

Solution : S type of stimulus
• type of activated receptor
S intensity
• number of activated receptors
• frequency of action potentials
S location
• location of activated receptors
• timing of receptor activation (for sound and smell)
S duration
• pattern of action potentials

Question 17

Receptor types

Answer 17

-chemoreceptors
• mechanoreceptors
• thermoreceptors
• nociceptors
• electromagnetic receptors

Question 18

Problem: interpretation of information

Answer 18

Solution : S process and integrate sensory information, starting in the
sensory pathways and culminating in the brain
S hierarchical and parallel processing of information
S different parts of the brain process different perceptions
S incorporation of information from different modalities in
higher association centres

Question 19

Sensation

Answer 19

• triggered by sensory stimuli
• travels to brain as action potentials (APs) via sensory
pathways

Question 20

Perception

Answer 20

• ability to discriminate various aspects of the stimulus

* meaningful interpretation of sensory data