Motor Control & Somatic Sensation Flashcards

(70 cards)

1
Q

What is the first step of a spinal reflex?

A

Stimulation of a receptor

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

What happens after a receptor is stimulated?

A

Activation of a sensory neuron

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

What happens after a sensory neuron is activated?

A

Information processing in the CNS

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

What happens after information processing in the CNS?

A

Activation of a motor neuron

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

What happens after activation of a motor neuron?

A

Response of a peripheral effector

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

How are spinal reflexes described?

A

Organised neural circuit which is contained within the spinal cord and is. reproducible, automatic response to a particular stimulus

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

What are the two types of reflex?

A

Stretch and withdrawal

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

What is the first step of a stretch reflex?

A

Stimulation of a receptor causes a stretch (receptor= muscle spindle)

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

What happens after stimulation of a receptor causes a stretch?

A

A sensory neuron is activated where the stretch occurred

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

What happens after a sensory neuron is activated where the stretch occurred?

A

Information processing in the CNS (spinal cord)

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

What happens after information processing in the CNS (spinal cord)

A

Activation of a motor neuron attached to muscle spindle

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

What happens after activation of a motor neuron attached to muscle spindle?

A

Response of a peripheral effector (contraction)

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

What is the muscle spindle involved in?

A

Stretch reflex (shortening of muscle) and posture

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

What is included in the muscle spindle?

A

Motor neurons from the CNS which innervate each muscle spindle

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

What is the first step of the withdrawal reflex?

A

Painful stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens after the painful stimulus in the withdrawal reflex?

A

To the posterior root ganglion

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

What happens after the posterior root ganglion in the withdrawal reflex?

A

Distribution within grey horns to other segments of the spinal cord and to the brain (more than one synapse)

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

What happens after the distribution within the grey horns to other segments of the spinal cord and to the brain in the withdrawal reflex?

A

Excitatory effect is relayed to flexors and relax effect is relayed to extensors to cause reciprocal inhibition

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

What happens in the brain during the withdrawal reflex?

A

Messages received in the spinal cord may be overridden by what is happening in the brain if there is other consequences of the movement

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

What is the function of the cerebellum in preparing for and performing movement?

A

Coordinates muscles guided by sensory feedback, compares intended movement with the actual result, helps maintain posture and gaze and helps learn and automate movements

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

What happens when preparing form movement in the brain?

A

The decision made in the frontal lobe is transferred to the premotor cortex and then to the cerebellum

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

What does the cerebellum do when performing voluntary movement?

A

Compares sensory feedback about the actual movement to the intended movement and signals adjustments to the primary motor cortex

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

What happens after adjustments have been signalled to the primary motor cortex?

A

Messages are conducted down the corticospinal pathway to the lower motor neurons so that motor units can be activated to cause muscle contraction

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

What can cerebellar deficits cause?

A

Ataxia characteristic ‘drunken gait’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the two types of sensory inputs into the brain?
Special senses and somatic & visceral sensations
26
What are some special senses?
Vision, hearing, taste, smell (& pheromones) and vestibular (balance)
27
What are some somatic & visceral sensations?
Touch, pain, warm & cold and body position
28
What is an example of direct inputs?
Hypothalamic temperature sensing
29
What is an example of endocrine inputs?
Food intake regulation
30
What type of neurons are sensory neurons?
pseudounipolar
31
What is the receipt for somatic & visceral sensation?
The ending of an afferent (somatosensory) neuron
32
What is the receptor for special senses?
A specialised receptor cell
33
What is inside the receptor cell?
Vesicles containing a chemical messenger
34
What is sensory receptors highly sensitive to?
A particular stimulus (modality)
35
What are the four types of information to describe a sensory stimulus?
MModality, intensity, duration and location
36
What is meant bu modality?
The type of sensory receptor activated
37
What is meant by intensity?
The frequency of action potential firing in afferent neuron
38
What is meant by duration?
Duration of action potential firing in the afferent neuron
39
What is meant by location?
Location of sensory receptors activated 'mapped' in the brain
40
What controls proprioreception?
Muscle spindle controls muscle length, body position, movement and posture
41
What are the sensory receptors of the muscle spindle?
The endings of the axon wound around the muscle fibres
42
What do touch receptors have?
A variety of different forms and special functions
43
What are some touch receptors associated with?
A single hair, the free nerve endings of pain receptors spread more widely in the skin and can respond to stimulation over a wider area (have a larger receptive field)
44
What happens when the stimulus is below threshold?
There is no response in the afferent neuron
45
What happens when there is an increasing stimulus?
Increases the action potential frequency and it is conducted down the axon.
46
What can stronger stimuli also do?
Activate more receptors sn action potentials in more sensory neurons
47
What are sensory receptors most sensitive to?
Change
48
What do sensory receptors often show?
Adaptation
49
What is adaptation?
Decreased output over time in response to continuous stimulation
50
What is an example of adaptation?
Thermoreceptors are most sensitive to changes in temperature, some touch receptors are most sensitive to vibration
51
What are the two types of receptors?
Tonic and phasic
52
What do tonic receptors do?
Are active all the time and the frequency of action potential increases when the stimulus increases
53
What is an example of a tonic receptor?
Muscle spindles that monitor and detect muscle length
54
What do phasic receptors do?
Occur in patches when on or off
55
What is an example of phasic receptors?
Touch receptors activated by vibration
56
What is the receptive field?
The region of space in which a stimulus can lead to activity in a particular afferent neuron
57
What does small fields and dense innervation do?
Gives good discrimination (detailed and accurate information)
58
Fields can...
Overlap, a strong stimuli may activation more than one
59
What is modality coded as?
A labeled line
60
What does a labeled line do?
Say what type the information is and where it has come from
61
What is in integration?
Cerebral cortex, couscous sensation and perception
62
What is in afferent neurons?
Peripheral nerve and tract or pathway
63
What is the sensory receptor?
Sensory stimulus converted into action potentials, TRANSDUCTION
64
What is the post central gyrus?
The primary somatosensory cortex
65
What is the parietal lobe?
Somatic sensory association cortex
66
What is sensation and where does it occur?
Conscious identification of 'what and where' occurs in the primary region of the cortex (post central gyrus)
67
What is perception and where does it occur?
Meaningful interpretation occurs in the association (secondary) region of the cortex- parietal lobe
68
What do areas of the somatosensory cortex correspond to?
Areas of the body
69
What occupies large regions of the somatosensory cortex?
Densely innervated areas of the body with small receptive fields
70
What does the left cortex represent?
The right side of the body and vice versa