Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neurology Year 3 > Somatosensory System > Flashcards

Somatosensory System Flashcards

1
Q

What three broad categories is the somatosensory system divided into?

A

Exteroceptive - cutaneous senses
Proprioceptive - posture and movement
Enteroceptive - internal state of the body

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

Where are first order neurones cell bodies located?

A

Dorsal root ganglia

Cranial ganglia - innovates anterior head

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

Where are second order neurones cell bodies located?

A

Dorsal horn or brainstem nuclei

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

Where are third order neurones cell bodies located?

A

Thalamic Nuclei

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

What does threshold mean?

A

The intensity of stimuli required to excite the sensory unit.

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

Low threshold receptors

A

Respond to low intensity generally non damaging stimuli
Mediate fine discriminatory touch
Thermoreception - cold to warm

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

Low threshold receptors - increasing stimuli strength

A

Increased rate of firing which denotes an increased intensity. However qualitative nature doesn’t change so long as only other receptors aren’t activated
e.g pressure doesn’t become pain

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

High threshold receptors

A 
Respond only to high intensity potentially damaging stimuli 
Mechanoreceptors
Thermal >45
Chemical - Substances
Polymodal - at least two of the above
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Adaption

A

Allows alterations to the firing rate in response to altered intensity or fire at a constant rate regardless of changing intensity.

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

Slow adapting neurones

A

e.g. stretch receptors
Fires continuously whilst deformed
Provides continual information
Amplitude of AP is still dependant on frequency

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

Fast adapting neurones

A

Muscle Spindle
Number of impulses is proportional to the rate of change
Detects change in stimuli strength

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

Very fast adapting

A

Respond to only very fast movement

e.g. Pacinian corpuscles and vibration

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

Conduction Velocity -Group 1

A

Thick myelination and large diameter
V.fast conduction
Proprioceptors of skeletal muscles

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

Conduction Velocity -Group 2

A

Moderate myelination and moderate diameter
Fast conduction
Mechanoreceptors of the skin

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

Conduction Velocity -Group 3

A

Thin myelination and small diameter
Moderate conduction
Pain and Temperature

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

Conduction Velocity -Group 4

A

No myelination and thin diameter
Slow conduction
Temp pain and itch

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

What is a receptive field?

A

Territory in which a sensory unit can be excited

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

What correlates inversely with receptive field?

A

The larger the receptive field the smaller sensory acuity, so less sensitive to touch.

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

What is sensory acuity?

A

The ability to differentiate between two separate points, in this case two points of pressure pain etc

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

Why is sensory acuity inversely proportional to the receptive field?

A

As increasing the receptive field decreases the innervation density.

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

A patch of skin may contain overlapping receptive fields with different modalities? T/F

A

True

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

Where are meissners corpuscles present?

A

Abundant in areas of very high activity, not present in hairy skin

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

Meissners Corpuscles

A

Sensitive to light touch

24
Q

Where are merkels discs present?

A

Same distribution but also found in hairy skin.

25
Q

Free nerve ending distribution.

A

Ubiquitous

26
Q

List the hair end organs

A

Krause end bulbs
Ruffins endings
Paccinian Corpuscles

27
Q

Krause End bulb distribution

A

Borders of dry skin and mucous membrane

28
Q

Ruffins endings distribution

A

Within dermis and joint capsules

29
Q

Paccinian corpuscles distribution

A

Dermis and fascia

30
Q

Ruffins Endings

A

Very little adaption and respond to sustained pressure

31
Q

Pacinian corpuscle

A

Vibration

32
Q

What three forms of pain are there?

A

Nociceptive
Inflammatory
Pathological

33
Q

Nociceptive

A

Adaptive

Immediate short lived protective

34
Q

Inflammatory

A

Adaptive
Assists in healing
Persistent

35
Q

Pathological pain

A

Maladaptive
No physiological purpose
V.Persistant

36
Q

Aδ fibres

A

Mechanical or thermal

Thinly myelinated

37
Q

Aδ describe the pain they relay.

A

First or fast pain

38
Q

C fibres

A

Unmyelinated nociceptors respond to all noxious stimuli

39
Q

C Fibres the pain they relay

A

Slow or second pain

e.g. throbbing aching etc

40
Q

Which receptors are activated by thermal stimuli?

A

TRP receptors

e.g. TRPA1

41
Q

Which receptors are activated by H+ stimuli?

A

ASICs

42
Q

Which receptors are activated by ATP

A

P2x

P2Y

43
Q

Which receptors are activated by bradykinin?

A

B2 receptors

44
Q

How can some sensory C fibres have efferent action?

A

They release pro inflammatory mediators upon activation.

45
Q

What Pro inflammatory mediators released by C fibres cause neurogenic inflammation?

A

CGRP

Substance P

46
Q

Substance P

A

Vasodilation
Promotes bradykinin and histamine release
Prostaglandin formation

47
Q

CGRP

A

Induces vasodilation

48
Q

What is the affect of pro inflammatory mediators being released by sensory neurones?

A

Induces Hyperalgesia (increased pain sensitivity )

49
Q

What is the main neurotransmitter in the dorsal horn?

A

Glutamate

50
Q

What is pain?

A

The relative and subjective perception of nociception.

Highly variable between patients.

51
Q

Visceral Pain

A

Poorly localised dull throbbing

Inflammation and ischaemia of internal organs

52
Q

Viscerosomatic Pain

A

Diffuse pain progressing to sharp well localised.

Inflammatory exudate contacts somatic structure.

53
Q

What is the gate control theory?

A

If non nociceptive sensory afferents are firing at such a greater rate than the nociceptive afferents. Then the synaptic transmission within the dorsal horn to the ascending tracts of the nociceptive axons does not occur.

54
Q

List the major nociceptive tracts

A

Spinothalamic

Spinoreticular

55
Q

Where do the spinothalamic nociceptive tract project too?

A

Thalamus

56
Q

Where do the spinoreticular nociceptive tract project too?

A

Reticular nucleus

57
Q

What is the function of the spinoreticular tract?

A

Autonomic response to pain

Neurology Year 3 (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions