Module D-01 Flashcards
Which regions of cerebral cortex are sensory cortex areas found?
parietal, occipital, temporal, and insular lobes
The process of converting the stimulus into a neuronal signal is called
Signal Transduction
The process of interpretation of sensory input
Perception
Behavioral responses that are triggered at SUB cortical regions
Reflexes
What are the 4 sensory receptor classes ?
1) Mechanoreceptors
2) Thermoreceptors
3) Chemoreceptors
4) Photoreceptors
Which sensory systems use Mechanoreceptors?
1) Somatosensory system
2) Vestibular system
3) Auditory system
Which sensory systems use Thermoreceptors?
Somatosensory system ( uses all sensory receptors except photoreceptors)
Which sensory systems use Chemoreceptors?
1) Somatosensory system
2) Olfactory system
3) Gustatory system
Which sensory systems use Photoreceptors?
Visual system
Perikaryon aka
soma
Which are the 6 sensory systems?
1) Somatosensory system
2) Vestibular system
3) Auditory system
4) )Olfactory system
5) Gustatory system
6) Visual system
Auditory hair cell is an example of a sensory _________, not a sensory __________ , therefore produces no _________
Receptor cell ;receptor neuron; Action Potentials
What 3 process occur in a sensory receptor NEURON:
1) Graded Receptor potential at the Transduction site
2) Action Potential in the axon
3) transmitter release at the terminal
__________ and ________ varies in Graded receptor potentials whereas the only variation in Action Potentials is the _________
Duration ; Intensity ; Frequency ( number of APs per time)
Area of axon where APs are generated once reaches threshold
Trigger zone (IIZ)
Trigger zone is sensory receptor neurons:
close to transduction site not at axon hillock ( motor neurons)
What type of cells are receptor cells like hair cells
Specialized Epithelial cells
What processes take place in a sensory receptor cell?
1) Graded Receptor Potential at the apical (transduction) site
2) Transmitter release at the base of the cell onto afferent fiber
What 4 Attributes are used to characterize a Sensory Stimulus?
1) Modality- type of stimulus
2) Intensity- amplitude
3) Duration- time
4) Location
How is stimulus Modality encoded in sensory systems?
Labelled line code
How is stimulus Intensity encoded in sensory systems?
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
How is stimulus Duration encoded in sensory systems?
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
How is stimulus Location encoded in sensory systems?
Receptive fields
What is the difference btw types of stimuli that slow and rapidly adapting receptors are more sensitive to?
-slowly adapting receptors - better in constantly monitoring
levels of stimulation
-Rapidly adapting receptors- most sensitive to
changes, not to constant stimulation
What is a receptive field?
area where responses can be induced in a certain neuron within a sensory pathway
What are the Three Basic Wiring Mechanisms of Sensory
Systems?
1) Convergence
2) Divergence
3) Lateral Inhibition
What is convergence?
When a second order neuron in a sensory pathway receives input from more than one first order neurons
What info does convergence in neurons give?
Where the information is coming from
What is divergence?
signal from one first order neuron diverges by sending axon collaterals to more than one subsequent neuron
Purpose of Divergence
tells us where the information is going to
Tor Fâ-Convergence , divergence and lateral inhibition are mutually exculsive
False , they may coexist
What does Lateral inhibition help with?
- Two point discrimination
- Perception of a single stimulus against its background
