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Integrative Neuroscience > Somatosensory Processing > Flashcards

Flashcards in Somatosensory Processing Deck (102):
1

Deformation of the DRG (free or encapsulated) by a mechanical stimulus _____ the threshold needed to evoke an action potential.

lowers

2

High-threshold channels characterize _____ (receptorss for pain).

nociceptors

3

Nociceptors are found predominantly in _____ _____.

smaller DRG

4

Nociceptors are activated by _____ pressures.

higher

5

Proprioceptors

Give information about the position of limbs and body in space.
Muscle spindles
Goldgi tendon organs

6

Stretching a mucle activates _____ on two types of afferent fibers:

mechanoreceptors
group 1a
group 2

7

Group 1a afferent fibers

large myelinated fibers
repidly adapting

8

Group 2 afferent fibers

myelinated fibers
slowly adapting

9

Tension of intrafusal fibers is also controlled by _____.

gamma motor neurons
(from dorsal horn spinal cord)

10

Large muscles for coarse movements have _____ spindles.

few

11

Extraocular muscles and uscles in the neck and hand have ____ spindles.

many
(require precise control)

12

Muscle spindles detect changes in _____.

muscle tension

13

Tactile afferents from body:

Dorsal column - medial lemniscal system

14

Afferents from face use the _____ (_____).

trigeminothalamic system
Trigeminal ganglion

15

Merkel receptors have _____ responses.

sustained

16

Meissner receptors are _____.

rapidly adapting

17

Pacinian receptors are _____.

rapidly adapting

18

Ruffini receptors have _____ responses.

sustained

19

Merkel receptors are responsible for _____ and _____ perception.

form
texture

20

Meissner receptors are responsible for _____ and _____.

motion detection
grip control

21

Pacinian receptors are responsible for _____ perception and _____.

vibration
tool use

22

Ruffini receptors are responsible for _____, _____, and _____.

tangential force
hand shape
motion direction
(stretch)

23

Slowly adapting afferents convey information about _____, such as size and shape.

spatial attributes

24

Rapidly adapting afferents convey information about ______: dynamic qualities of the stimulus.

changes in ongoing stimulation

25

Sensory axons are classified according to their _____, which governs their _____ and their _____.

diameter
myelination
conduction velocity

26

Dermatome

Cutaneous innervation related to a single spinal nerve

27

sensation

transduction
transmission

28

perception

inference
deduction
follow-up

29

5 primary tasks of sensory systems

transduction
transmission
inference
deduction
follow-up

30

5 qualities of information to encode

modality
intensity
duration
location
salience

31

5 factors that influence success or failure

fatigue
adaption
sensitization
overlap/redundancy
damage/overload

32

Dorsal root ganglia

contain the sensory neurons of the somatosensory system

33

Dorsal root is responsible for _____.

sense

34

Ventral root is responsible for _____.

motor

35

The _____ system is responsible for touch perception.

dorsal column-medial lemniscus system

36

The _____ is responsible for pain perception.

anterolateral system

37

The _____ projects to the cerebellum and controls timing of muscle contractions.

dorsal spinocerebellar tract

38

Proprioceptive afferents from the body lead to the _____ and _____.

cerebellum
dorsal column nuclei

39

The _____ somatosensory thalamus contains _____ afferents from the body.

central posterior lateral
medial lemniscus

40

The _____ somatosensory thalamus contains _____ afferents from the face.

ventral posterior medial
trigeminal lemniscus

41

the somatosensory cortex contains _____ __, __, _, and _.

Brodmann's areas
3a
3b
1
2

42

The _____ is a representation of the human body from the _____.

homunculus
somatotopic map

43

_____ serves as obligatory first step in cortical processing of somatosensory information.

Brodmann's area 3b

44

_____ are functioal modules of the cortex.

Columns

45

Columns in the somatosensory cortex are _____.

functionally distinct

46

Reorganization of cortical maps in response to altered functional input is known as _____.

plasticity

47

Nociception

The neural encoding and processing of noxious stimuli

48

Noxious stimuli

stimuli that can elicit tissue damage and activate nociceptors

49

Nociceptors are sensory receptors that detect signals from _____ and respond to _____ released.

damaged tissue
chemicals

50

Nociceptors are _____ found in the skin, muscle, joints, bone, and viscera.

free (bare) nerve endings

51

Pain processing is _____ of normal cuteaneous processing.

independent

52

Peripheral axons responsible for normal stimulation _____ their frequency in response to painful stimuli.

do not increase

53

Nociceptive afferents only fire when _____.

stimuli reach high intensities

54

Direct stimulation of large fibers (1a, II, AB) _____.

does not produce pain

55

Peripheral nociceptive axons terminate in "_____."

free endings

56

Nociceptors are found on _____ fibers (_, _)

small
Ad
C

57

C fibers are _____ and respond to _____, _____, and _____ stimuli.

polymodal
thermal
mechanical
chemical

58

_____ fibers lack myelination.

C

59

Type I Ad fibers respond to dangerous _____ and _____ stimulation.

mechanical
chemical

60

Type II Ad fibers respond to _____ stimulation.

thermal

61

_____ respond only to intense mechanical stimulation such as pinching, cutting, or stretching.

High threshold mechano-nociceptors

62

_____ respond to intense mechanical stimulation as well as to thermal stimulation.

Thermal nociceptors

63

_____ respond only to chemical substances.

Chemical nociceptors

64

_____ respond to all high intensity stimuli.

Polymodal nociceptors

65

_____ include high-threshold mechanoreceptors, polymodal nociceptors, and ''silent'' nociceptors.

Joint nociceptors

66

_____ include mechanoreceptors, thermal, silent and chemical nociceptors.

Visceral nociceptors

67

C and Ad fiber nerve endings contain _____ that respond to temp, pressure, and inflammatory agents.

transient receptor potential (TRP) channels

68

TRPV1 is activated by _____, _____, _____, and _____.

heat
anandemide
capsaicin
allyl isothiocyanate

69

TRPV1

Transient receptor potential vanilloid type-1

70

TRPV1 channels are also known as _____ and _____.

capsaicin receptors
vanilloid receptor 1

71

_____ are produced peripherally in response to injury.

Endovanilloids

72

ASIC

acid-sensing ion channel

73

Hyperalgesia

Increased sensitivity to painful stimuli

74

Hyperalgesia has a _____ effect at the level of the nociceptors.

peripheral

75

Tissue damage and inflammation release inflammatory mediators, such as _____, _____, and _____ which increase the sensitivity of nociceptors to _____.

prostaglandins
histamin
substance P
noxious stimuli

76

Most sensitizing pro-inflammatory agents activate the _____ pathway.

phospholipace C

77

Phospolipace C pathway phosphorylates TRPV1, leading to _____.

sensitization of TRPV1

78

Allodynia

Pain sensation in response to non-painful stimuli

79

Allodynia results from an increase in excitability of _____.

dorsal horn neurons

80

The _____ localizes painful or thermal stimuli and leads to the _____.

spinothalamic tract (lateral and anterior)
thalamus (central lateral nucleus)

81

The _____ causes alertness and arousal in response to painful stimuli and leads to the _____.

spinoreticular tract
reticular formation (through ret.form. of medulla and pons)

82

The _____ orients the eyes and head towards the stimuli and leads to the _____.

spinotectal tract
tectum (through periaqueductal gray matter)

83

The dorsal root ganglia pathway goes through _____.

Lissauer's tract

84

Crossing of the anterolateral tract from left to right spinal cord occurs at the _____.

decussation

85

Visceral pain misperceived as somatic pain is called _____.

referred pain

86

Non-nociceptive fibers of the anterolateral tract terminate in _____.

layer 5

87

Unilateral spinal cord lesions lead to "dissociated sensory loss":
contralateral:_____
ipsilateral:_____

reduction in pain/temp sensation
reduction in touch/pressure/vibration/proprioception

88

The anterolateral system from the body runs through the _____ and the _____.

spinothalamic tract
Ventral posterior lateral nucleos of the thalamus

89

The anterolateral system from the face runs through the _____ and the _____.

Trigeminothalamic tract
Ventral posterior medial nucleus of the thalamus

90

Sensory discriminative aspects of pain

location
intensity
quality

91

Affective motivation aspects

fear
anxiety

92

The anterolateral system is divided into _____ and _____.

sensory-discriminative
affective-motivational

93

The sensory-discriminative anterolateral system leads to the _____.

somatosensory cortex

94

Stimulation of the periaqueductal gray in the midbrain is _____.

analgesic

95

_____ in the spinal cord modulate pain perception.

Local interactions

96

Nociceptive information is modulated by simultaneous activity in _____.

touch fibers

97

Opiod

Peptide that binds to the same posynaptic receptors as opium

98

_____ is the active ingredient in the sap/seeds of opium poppies.

Morphine

99

Morphine, heroin, and synthetic opiates such as methadone and fentanyl are potent _____.

analgesics

100

3 groups of endogenous opioid receptor ligands:

endorphins
enkephalins
dynorphins

101

_____ modulate transmission of ascending pain signals.

Descending systems

102

_____ are released directly in the spinal cord to blunt the effects of nociceptor activation.

Enkephalins