Brainscape's Knowledge GenomeTM

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


See full index

NeuroEndo Exam 2 > Lecture 11: Sensory Physiology > Flashcards

Lecture 11: Sensory Physiology Flashcards

1
Q

Sensory Aα What is its classification of afferent fibers? Is the fiber diameter large of small? What is its conduction velocity? What receptors does it supply?

A

Ia and Ib large 80-120 m/s (fast) Primary muscle spindles and Golgi tendon organs

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

Sensory Aβ What is its classification of afferent fibers? What receptors does it supply?

A

II Secondary muscle spindles, skin mechanoreceptors

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

Sensory Aδ What is its classification of afferent fibers? What receptors does it supply?

A

III Skin mechanoreceptors, thermal receptors, and nociceptors

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

Sensory C What is its classification of afferent fibers? Is the fiber diameter large of small? What is its conduction velocity? What receptors does it supply?

A

IV small 0.5-2 m/s (slow) Skin mechanoreceptors, thermal receptors, and nociceptors

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

Motor Aα What receptors does it supply?

A

Extrafusal skeletal muscle fibers

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

Motor A(gamma) What receptors does it supply?

A

Intrafusal skeletal muscle fibers

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

Motor B What receptors does it supply?

A

Preganglionic autonomic fibers

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

Motor C What receptors does it supply?

A

Postganglionic autonomic fibers

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

What are rapidly adapting receptors

A

Receptors that respond only at the beginning or end of a stimulus (only active when stimulus intensity increases or decreases)

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

What are Slowly adapting receptors

A

Receptors that respond to prolonged and constant stimulation

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

What does Meissner corpuscle sense?

Is it RA or SA?

A

Touch and vibration; flutter and tapping <100 Hz

RA

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

Where is Meissner corpuscle located?

A

Glaborous skin

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

What does Pacinian corpuscle sense?

RA or SA

A

High frequency vibration

Very RA

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

Where is Pacinian corpuscle located?

A

Both hairy and glaborous skin

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

What does Ruffini corpuscle sense?

RA or SA

A

Magnitude and direction of stretch Touch, pressure, and proprioception

SA

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

Where is Ruffini corpuscle located?

A

Both hairy and glaborous skin

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

What does a Merkel cell sense?

RA or SA

A

Pressure

SA

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

Where is a Merkel cell corpuscle located?

A

Glaborous skin

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

What does a hair follicle receptor sense?

RA or SA

A

Motion across skin and directionality of that motion

RA & SA

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

What does a tactile free-nerve ending sense?

RA or SA

A

Pain and temperature

SA

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

What is tactile acuity

A

Ability to sense small or large differences in stimuli

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

What is a receptive field

A

The range of which a receptor is active

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

What is two point discrimination?

A

Ability to distinguish between two stimuli applied at a close distance. It is determined by measuring the minimum distance between the two stimuli

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

Where is tactile acuity the highest? Are receptive fields small or large?

A

Fingertips and lips

Small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where is tactile acuity the lowest? Are receptive fields small or large?

A

Calf, back, thigh

Large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where is Somatosensory area 1 located?

A

Post central gyus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the function of Somatosensory area 1?

A

Integration of information for position sense, size, and shape discrimination

28
Q

Where is Somatosensory area 2 located?

A

Wall of Sylvian Fissure (under lip of S1) Receives input from S1

29
Q

What is the function of Somatosensory area 2?

A

Responsible for comparisons between objects, different tactile sensation, and deciding what becomes a memory

30
Q

What is the function of parieto-temporal-occipital association area?

A

High level interpretation of sensory inputs. Receives input from multiple sensory areas.

31
Q

What is the law of projection?

A

No matter where along the afferent pathway a stimulation is applied, the perceived sensation arises from the origin of the sensation.

32
Q

What phenomenon can the law of projection explain?

A

Phantom limb

33
Q

What is pain?

A

An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

34
Q

What is nociception?

A

The neural process of encoding noxious stimuli

35
Q

What is hypersensitivity?

A

Increased responsiveness of nociceptive neurons to their normal input, and/or recruitment of a response to normally subthreshold inputs

(excessive sensitivity to something that shouldn’t be that sensitive)

36
Q

What is hyperaesthesia?

A

Increased sensitivity to stimulation, excluding the special senses

(increased sensitivity to a stimulation)

37
Q

What is hyperalgesia?

A

Increased pain from a stimulus that normally provokes pain

(more pain than there should be)

38
Q

What is allodynia?

A

Pain due to a stimulus that does not normally provoke pain. Classic example is the lay of sheets on skin that has been sunburned.

(Pain when there shouldn’t be pain)

39
Q

What are C-fibers

A

Very thin

slowly conducting

unmyelinated neurons

Large receptive field

produce a throbbing dull pain sensation

Imprecise location of pain

40
Q

What are A delta fibers

A

Fast conducting

myelinated

small receptive field

precise localization of pain

Sharp pain

41
Q

What are mechanical nociceptors?

A

Response to mechanical forces ranging from moderate pressure with a blunt object to overtly tissue-damaging stimuli

42
Q

What are chemical nociceptors?

A

Response to endogenous or exogenous chemical compounds, such as pro-inflammatory mediators, acids, or capsaicin

43
Q

What are thermal nociceptors?

A

Response to noxious heat and cold will directly activate thermal receptors expressed by nociceptors

44
Q

What is the function of the transient receptor potential (TRP) family of receptor ion channels?

A

Sense a broad range of changing environments in the body tissue: pH, inflammatory mediators, heat, cold, and exogenous chemicals.

When active are permeable to Ca2+, Na+ & K+

45
Q

What activates TRPV1

A

Capsaicin (hot pepper)

bradykinin

intense heat

46
Q

What pain conditions is TRPV1 involved with?

A

Migraine

dental pain

cancer pain

inflammatory pain

visceral pain

osteoarthritis

47
Q

What activates TRPA1

A

Allyl isothiocyanate in mustard oil, wasabi and horseradish

non chilly pepper heat

48
Q

What pain conditions is TRPA1 involved with?

A

Dermatitis

Chronic itch

Painful bladder syndrome

Migraine

Irritable bowel syndrome

Panreatitis

49
Q

What activates TRMP8

A

Cold temperatures and agents (menthols)

50
Q

What happens where there are no pain inputs to the C fibers?

A

Inhibitory interneurons suppress pain pathway

51
Q

What happens when there are pain inputs to the C fiber?

A

C fibers stop the inhibitory interneurons and send a strong signal to brain

52
Q

How can pain be modulated as proposed by the gate control theory?

A
  1. Aβ fiber is activated and travels to dorsal horn and synapses on an inhibitory neuron, releasing an EAA.
  2. Released glycine inhibits secondary sensory neuron on nociceptive pathway.
  3. Rubbing an area of affected skin actiaves the Aβ fiber and reduces the sensation of pain
53
Q

How are pain signals reduced via descending inhibition?

A
  1. Activation of Periaqueductal grey matter by opiates, EAA & cannabinoids leads to fibers going to Locus Coeruleus (NE) and Raphe nucleus (serotonin)
  2. NE and serotonin released into dorsal horn and activate inhibitory interneurons
  3. Local inhibitory interneurons release opiates and activate mu receptors on pre-synaptic terminals of C-fibers, reducing nociception
54
Q

What does the theory of central sensitization say?

A
  1. Level of spinal cord, higher brain areas, or both
  2. Reduces threshold of involved neurons to noxious stimuli
  3. Synaptic Plasticity: Persistent stimulation of NMDA receptors and intracellular signaling cascades
  4. Central Inflammation
55
Q

What does the theory of peripheral sensitization say?

A
  1. Inflammation can make nociceptors in injured tissues more sensitive (e.g. Prostaglandins and bradykinin)
  2. Body more sensitive to thermal changes, activating TRPV1
56
Q

What role does the primary sensory cortex play when it comes to the sensory system?

A

Identifies size and shape of an object

57
Q

What role does the secondary sensory cortex play when it comes to the sensory system?

A

Cognitive interpretation of crude senses & compares objects by touch alone.

58
Q

What role do the primary and secondary sensory cortices play when it comes to pain?

A

Receive input from nociceptors and play a role in localization of pain

59
Q

What role does the insular cortex play when it comes to pain?

A

Interpretation of pain

Integrates all signals related to pain

60
Q

What role does the amygdala play when it comes to pain?

A

Emotional component of pain

61
Q

What role does the hypothalamus/medulla play when it comes to pain?

A

Integrate physiologicak change associated with visceral pain

62
Q

Free nerve endings

A

Peripheral terminals of nociceptor axons that lack specialzed receptor cells or encapsulations. Can either be peptidergic or non-peptidergic.

63
Q

Peptidergic Nociceptors

A

Express neuropeptides: Substance P and CGRP

Sense chronic inflammation & visceral pain

64
Q

What up-regulates neuropeptides?

A

Chronic inflammation

65
Q

Non-peptidergic Nociceptors

A

Does not express CGRP or Substance P

Involved in somatic chronic pain states such as diabetic neuropathy

NeuroEndo Exam 2 (13 decks)

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