Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Motor Control > Stimulus Elicited Behaviour > Flashcards

Stimulus Elicited Behaviour Flashcards

1
Q

What is stimulus -elicited behaviour? 2

A

object/event ->animal->behaviour
behaviour that is produced as an involuntary and relatively immediate consequence of sensory stimulation: the behaviour is an involuntary response to the stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

eliciting stimulus

A

any stimulus that is effective at eliciting a particular behavioural response. such a stimulus is then an eliciting stimulus for that particular behaviour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Response latency

A

period of time that elapses between the onset of the stimulus and the onset of the (involuntary) response it elicits - too soon its spontaneous, too long its voluntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2 ways a stimulus elicits a behavioural response

A

stimulus drive the response

stimulus releases the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

stimulus driven response

A

stimulus elicited behaviour in which the neural activity that causes the muslce contraction derives directly from that evoked by the eliciting stimulus in axons of sensory neurons - being poked - each time we stimulate receptor sensory neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

stimulus released response

A

stimulus elicited behaviour where the neural activity that causes the muscle contractions does not derive from the eliciting stimulus. The activity is produced by a response generating mechanisms that generates it when it receives a signal derived from the eliciting stimulus - chicken running for cover - brief stimulus can elicit a continuous response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

all or nothing for stimulated responses

A

once the response has been triggered - it will be executed to completion regardless of whether the elicitng stimulus persists or not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

reflex

A

discrete action or period of sustained activity (possibly repetitive) that is produced as a direct, involuntary, and relatively immediate response to the stimulation of a specific pop. of sensory receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how do we lessen the effect of a reflex

A

brace ourselves when we know something is about to happen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

autonomic responses vs skeletomotor behaviour

A

stimulus goes to sensory system - then either autonomic NS for cardiac and smooth for a autonomic response, or somatic NS for skeletal muslces for skeletomotor behaviors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

elemental reflexes 2

A

components of complex, and goal directed reflexes
standard reflex in which the response is confined to a single, specific muscle and cannot be meaningfully divided into separate response components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Kandel - motor coordination

A

process of linking the contractions of many indeendent muslces so that they can act together and can be controlled as a single unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sir Charles Sherrington - early perspective of movement

A

simple reflexes are the basic units for movement; complex sequences of movements are produced by combining activity of simple reflexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Contemporary perspective of movement

A

neural circuits that produce motor output are activated by centrally generated motor commands as required to produce adaptive movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Spinal cord circuitry function - 3

A 
provides means of linking muslces together - synergistic activation of AG/ANT muscle pairs via reciprocal inhibition 
provide elementary patterns of behaviour - reflexes (simple and complex) without descending outputs (we dont need info from the brain 
permits regulation (modulation) of excitatory afferent input - reducing effectiveness and inhibition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

2 methods to reduce effectiveness of excitatory inputs

A

presynaptic inhibition
postsynaptic inhibition
inhibiting cells before or after the synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

3 ways of presynaptic inhibition

A

alters presynaptic membrane permeability and reduces probability of AP firing - subthreshold depolarization so when it gets depolarized its a smaller distance that it has to travel - determines the amount of neurotransmitters released
reduces the amount of neurotransmitter released at presynaptic terminal
selectively reduces effectness of synaptic inputs to postsynaptic membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

2 ways of postsynaptic inhibition

A

inhibition occurs on postsynaptic cell body membrane - axosomatic
makes postsynatic neuron less sensitive to excitatory input due to membrane hyperpolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

2 examples of postsynaptic inhibition

A

Ia- IN interneurons

renshaw cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

spinal reflex

A

any reflex mediated by neural mechanisms that are confined to the peripheral NS and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

spinal reflex is discovered from

A

decerebrate preperations - Sherrington’s cats where they isolated the brain from the spinal cord but still saw reflexes menaing there is no need for input from the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

current perspective of reflex output

A

reflex output/motor response can be modified to meet task demands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Reflex arc

A

a linked chain of individual neruons that connects a single sensory receptor to a single alpha MN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

afferent neuron in a reflex circuit

A

convey stimulus detection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
efferent neuron in a reflex circuit
induces muslce contraction
26
central processing unit in a reflex circuit
simple or complex
27
types of reflexes categorized by number of synapses
monosynaptic - just one disynaptic - 2 - 1 interneuron trisynaptic - 3 - 2 interneurons polysynaptic - more than 3 - more than 2 interneurons
28
simple circuitry: interneurons (2) - where are they and what do they do?
neurons restricted to spinal cord | able to influence nearby neurons - propriospinal neurons
29
reflex latency and 3 components
time delay between stimulus and reaction Delta Ta - time of afferent conduction Delta Te - time of efferent conduction - neuron type, length of fibre, health of neuron Delta Tc (central delay) - central processing unit - 1-5ms - number of synapses
30
MSR (5)
monosynaptic stretch reflex, stretch reflex, deep tendon reflex, T-reflex, myostatic reflex
31
MSR pathways
densely interconnected
32
LLoyd and Renshaw via intracellular recording - Neural circuitry - 4
Ia discharge - exitation homonymous - sensory and motor to the same muscle Excitation homonymous and synergistic inhibition antagonist MST latency ~70ms quickest as a mono and most simple
33
reciprocal innervations
innervation to AG/ANT muscle gps from same neuron source - same Ia afferent goes to agonist and antagonist
34
reciprocal inhibition (2)
neuron source contribution to inhibition of muscle groups antagonistic to prime mover muscle groups an effect of reciprocal innervation
35
the stronger the stimulus - response?
the more vigorous the response
36
reflex threshold
lowest strength of the eliciting stimulus that is capable of reliably eliciting the reflex response
37
the longer the stimulus duration - response duration
longer
38
the stronger the eliciting stimulus - latency
shorter
39
natural reflexes inherit the properties of
elemental reflexes
40
MSR gain
Spinal cord excitability | magnitude motor response relative to the magnitude of sensory stimulus - output:input
41
MSR gain for the same magnitude of input i.e. muscle stretch
``` high force (motor) output - high gain - throwing our glass of water over our shoulders low force (motor) output - low gain - ```
42
Gain
effectiveness of reflex pathways
43
Neural mechanisms of reflex gain - principle
reflex gain is set according to task demands
44
3 contributing neural mechanisms that can provide explanation for a change in reflex gain?
fusimotor activity presynaptic modulation postsynaptic modulation
45
how does fusimotor activity change reflex gain? - 5
Gamma MN regulate sensitivity of spindle to stretch gamma activation will prestretch central regions of intrafusal fibres and alter their sensitivity to streth - gamma bias, fusimotor set, gamma drive ensures AP firing at onset of stretch, during stretch, and stretch termination same stimulus intensity - different AP firing preloaded muscle provides earlier and more robust afferent response - theoretically, more fdbk
46
postsynnaptic modulation
postsynaptic membrane (alpha MN) altered by direct input to alpha MN cell body - altering excitability of alpha MN pool
47
3 potential contributing factors to absent or weak response of MSR gain
disorder of reflex circuit - sensory/motor axon or cell bodies, synaptic transmission disorder "higher order" disorder - hyperactive pre/pose inhibition peripheral disorder - muslce spindle receptor
48
overactive response of MSR - potential diseases
Hyperactive MSR - quicker and larger in magnitude | high MSR gain - disorders of muslce tone (spasticity and rigidity)
49
potential contribution factor of overactive response of MSR
caused by "high order" disorder (lesions) which removes descending inhibition - highest being spinal cord injuries
50
spinal shock
no reflex the first day but overactive reflex after
51
bottom line of reflex gain
spinal cord circuitry plays a major role in modulation of reflex gain
52
excitability of spinal cord
"state" of alpha MN pools
53
Spinal cord excitability provides insight into 2
potential for alpha MN to respond to sensory input - types include real/sensory fdbk or imposed/electrical current potential for alpha MN to receive descending drive - descending motor commands
54
Does reflex gain change? or are alpha MN more/less receptive to excitation -2 ways
eliminate peripheral contribution to reflex gain - isolate central contribution determine input:output ratio - Hoffman reflex/H reflex testing
55
H reflex
Hoffman reflex - electrical analog of the stretch reflex | Motor response elicited by electrical stimulation of Ia afferent nerve - introduces AP into afferent nerve
56
H reflex latency
~30ms - eliminating activation of muslce spindle which eliminates the fusimotor/generation of the AP and only travels on one side
57
Principle of reflexive vs direct simulation of muscle fibres
stimulation intensity dictates neuron activation - large fibre axons activated at low stimulation intensity
58
at low stim intensity
Ia afferent recruitment leading to reflex-based motor response
59
what happens when stimulation intensity increases?
recruitment of smaller neurons - alpha MN - direct stimulation of muscle fibres - M wave/response - latency of 3-8ms because it only has to travel along the remainder of the alpha MN - NOT reflexive
60
Low stim intensity
no response
61
increased stim intensity
Ia recruitment; H reflex
62
higher increased stim intensity
Ia and Alpha MN recruitment - M-response and increased amplitude H-reflex
63
higher higher increased stim intensity
M-wave amplitude increase due to MN recruitment - plateau when we see all of our MN fire H-reflex amplitude decrease due to an electrical blockage
64
electrical blockage
antidromic and orthodromic AP propagation following electrical stimulation efferent axon orthodromic propagation = M-wave antidromic propagation "blocks" orthodromic Ia propagation at axon hillock which blocks Ia induced efferent AP
65
Who's the monitor for stim intensity?
M-wave amplitude
66
Neural mechanisms underlying alterations in H-reflex gain?
Clinical test of integrity of central mechanisms in altering excitability of alpha MN pool voluntary muslce activation leads to postsynaptic excitation of agonist alpha MN pools - stim of Ia during voluntary activation will cause increased H-wave amp (due to Ia synaptic connection to excited alpha MN pools)
67
H reflex + voluntary muslce activation
test effectiveness of central mechanisms for altering excitability of alpha MN pools
68
What does it mean when the behaviour elicited happens too long, too short, or just right?
too long - voluntary response too short - spontaneous/ coincidental just right - involuntary reflex
69
postsynaptic inhibition is what kind of synapse?
axoaxonic
70
spinalised cats - 2 | muscle stretch - 2
Charles Sherrington decerebrate preparation - increased extensor tone - heighten spinal reflexes brisk muscle stretch - contraction of stretched muscle and relaxation of antagonist muscle
71
presynaptic modulation
alters effectiveness of synaptic inputs to alpha MNs
72
absent/weak response means
hypoactive MSR/low MSR gain
73
constant stim intensity and H wave fluctuations
increase of H wave means means an increase in reflex gain, decrease means reflex modulation
74
low stim vs high stim and what they activate
larger afferents vs smaller afferents and large efferents
75
peripheral mechanisms of reflex gain
fusimotor
76
central mechanisms of reflex gain
presynaptic and postsynaptic modulation
77
stimulus duration is coded by - skin
cutaneous and subcutaneous mechanoreceptors which have a low threshold - high sensitivity
78
sensory map
sensory homunculus
79
stim vs blockade
if the stim remains the same, so will the blockade
80
The function of the gamma motor system
Regulate sensitivity of muscle spindles for detecting stretch
81
Stimulation intensity dictates?
Neuron activation - large fibre axons activated at low stim intensity
82
Recurrent collateral of RENSHAW
Collateral of alpha MN that synapses with the RENSHAW cell itself
83
Sustained rhythmic alteration does not depend on?
Supraspinal inputs

Motor Control (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions