intro to sensory Flashcards
1
Q
define exteroceptor
A
- receptor that relay whas is happening in the external environment (touch, hearing, taste, olfaction, vision)
2
Q
define interoceptor
A
- relays what is happening in the internal environment
3
Q
define proprioceptor
A
- relay what is happening in the musculoskeletal system
4
Q
define transduction
A
- process by which energy of physical stimulus is detected and CONVERTED into a form of energy used by nervous system
- physical stimulus CONVERTED into RECEPTOR POTENTIAL in a specialized receptor cell or sensory receptor ending
5
Q
define adequate stimulus
A
- under normal circumstances a specific receptor is affected by only one stimulus modality (this is adequate stimulus)
6
Q
define nociceptor
A
pain receptor (noxious)
7
Q
define receptive field
A
- region of tissue within which a stimulus can evoke a change in the firing rate of a neuron
8
Q
receptor potential vs action potential
A
- Receptor potential = CHANGE in membrane potential produced by a transducer mechanisms (is a LOCAL, GRADED POTENTIAL)
- Most receptor potentials are depolarizations
- IF DEPOLARIZATION reaches Threshold, an ACTION POTENTIAL is generated
- rate of action potential generation INCREASES as receptor potential rises higher above threshold
9
Q
How does the nervous system code for “what”
A
- labeled line principle = receptors/neurons code for specific stimuli
10
Q
how does the nervous system code for Where
A
- receptor field of a neuron is the region of tissue within which a stimulus an evoke a change in firing
- sensory pathways create a somatotopic maps
- lateral inhibition is a way to enhance boundary contrasts.
11
Q
how does the nervous system code for intensity
A
- signal strength increases by:
- -> increasing frequency of nerve impulses (TEMPORAL SUMMATION) = frequency)
- -> increasing the # of fibers activated (spatial summation = population)
- Stimuli of different intensities may activate different sets of sensory receptors
12
Q
how does the nervous system code for duration
A
- maintain continuous signal during stimulus
- have on and off signal
13
Q
define adaption of receptors
A
- maintained stimulus of constant strength is applied to a receptor, the frequency of AP in receptors sensory nerve decreases over time
- -> general property of sensory receptors
- -> receptors have different mechanisms of adaption
- -> probably all mechanoreceptors would completely adapt eventually
14
Q
describe Non-adapting
A
- often lumped with tonic receptors
- NOCICEPTORS
15
Q
describe slowly adapting (TONIC)
A
- give continuous info about stimulus (STRENGTH + DURATION)
- not useful at low stimulus intensities
- MERKEL CELL ENDINGS (disks), Ruffini end organ, Baroreceptors
