Neuro Exam 2

Front 1

somatosensory info converges in ___ lobes of cortex

Back 1

parietal lobe

Front 2

primary somsethic area

Back 2

(3,1,2); primary sensations

Front 3

secondary somesthetic area

Back 3

(40) bilateral connections - bimanual skills

Front 4

sensory association area

Back 4

(5,7) perceptual interpretive fxn

Front 5

sensory info flow in brain

Back 5

thalamus to primary somatosensory cortex to secondary somatosensory cortex, primary supplementary motor cortex (frontal lobe), posterior parietal cortex sensory association area

Front 6

primary cortical receiving area

Back 6

primary somatosensory cortex SI, includes post central gyrus (BA 312)

Front 7

primary somatosensory cortex (SI) neurons are responsive to

Back 7

somatosensory stimuli almost exclusively- proprioception, pain, tactile perception (texture, shape, size), vibration, thermal sensation, edge detection, stereognosis

Front 8

how is primary somatosensory cortex organized

Back 8

somatotopically organized- sensory homunculus

Front 9

To appreciate the shape, texture, size, weight,and movement of a given object, the somatosensory cortex must integrate theparallel streams of information carried by the

Back 9

medial leminiscal pathway

Front 10

destruction of primary somatosensory cortex

Back 10

severe deficits in discriminative touch and proprioception on contralesional side of body; deficits in ability to accurately localize and recognize objects by shape, texture and size, vibrating/moving stimuli; also deficits in fine motor coordination

Front 11

secondary somatosensory area (SII) location

Back 11

small area in ventral portion of post-central gyrus (40)

Front 12

secondary somatosensory area receives extensive input from

Back 12

primary somatosensory area and thalamus

Front 13

function of secondary somatosensory area

Back 13

shape and texture discrimination and bilateral secondary somatosensory areas strongly linked which could explain involvement in bilateral activities; processing for graphasthesia

Front 14

BA of somatosensory association area

Back 14

5, 7

Front 15

highest degree of convergence of somatosensory info occurs in

Back 15

posterior parietal cortex (receives axons of primary and secondary somatosensory association areas)

Front 16

damage to neurons in somatosensory association area

Back 16

affect ability to recognize objects even though objects can be felt (tactile agnosia)

perceptual deficits: unilateral neglect (non dominant hemisphere lesions), Pusher's syndrome (poor vertical orientation)

Front 17

Pusher's syndrome

Back 17

poor vertical orientation (damage to somatosensory association area)

Front 18

contralateral cortical damage in somatosensory cortex

Back 18

accurate for touch but unable to localize

Front 19

lesions in somatosensory cortex

Back 19

contralateral anesthesia, paresthesia, impaired sensory fxn

Front 20

contralateral parietal lobe damage

Back 20

tactile extinction

Front 21

tactile extinction

Back 21

ability to sense touch separately but not able to identify bilateral simultaneous touch

Front 22

ability to sense specific touch but unable to identify graphing letters on hand or recognize objects on manipulation

Back 22

parietal lobe damage

Front 23

what is usually retained in somatosensory cortical lesions

Back 23

vibration sense

Front 24

loss of ability to sense pain (lesion locations)

Back 24

damage to pain receptors, lateral spinothalamic tract, primary sensory cortex

Front 25

damage to medial pain systems

Back 25

changes in attention to pain modulation of pain sensations and affective response to pain

Front 26

what would indicate that the DC-ML system from peripheral to somatosensory cortex is intact

Back 26

awareness of touch and ability to locate; ability to discriminate 2 simultaneous points of contact

Front 27

parietal lobe damage can result in

Back 27

unilateral neglect, impaired vertical orientation, tactile agnosias

Front 28

somatosensory system

Back 28

elements of PNS and CNS that subserve sensory modalities of touch, vibration, temp, pain, proprioception; sensory info that comes from skin and MSK system

Front 29

flow of somatosensory system (AP if stimulus is strong enough)

Back 29

receptors to afferents to cell body in DRG to posterior horn of SC to ascending tracts to brainstem to thalamus to cortex

Front 30

superficial or cutaneous sensation (exteroceptive)

Back 30

info from skin and subcutaneous tissue

Front 31

types of superficial/cutaneous sensation

Back 31

touch (coarse, discriminative), temp (relative and delta temp), pain (fast and slow)

Front 32

discriminative touch

Back 32

light touch, tactile threshold, superficial vibration/flutter, pressure, skin stretch, form, texture

Front 33

coarse touch

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crudely localized touch, tickle, itch

Front 34

pain

Back 34

any noxious sensation, sharp, dull, local, diffuse, burning, stabbing; fast or slow

Front 35

deep sensations

Back 35

pain and proprioception; info from MSK system

Front 36

types of deep sensations

Back 36

joint position sense, kinesthesia, vibration

Front 37

proprioception

Back 37

awareness of position and mvm to limbs in relation to each other and the body; knowledge about position of our bodies in space

Front 38

cortical fine touch sensations

Back 38

higher order sensations dependent on intact cutaneous and deep sensory fxn

Front 39

cortical final touch sensations types

Back 39

2 point discrimination, bilateral simultaneous stimulation, graphesthesia, localization of touch

Front 40

2 point discrimination

Back 40

ability to discern that 2 nearby objects touching skin are truly 2 distinct points, not one

Front 41

bilateral simultaneous stimulation

Back 41

ability to determine 2 simultaneous stimulations are being applied to opposite sides of body, prox and distal on same side

Front 42

tactile extinction

Back 42

from unilateral cerebral damage; inability to recognize 2 simultaneous stimuli on opposite sides of body, or proximally and distally, though either one can be sensed alone

Front 43

graphesthesia

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ability to recognize writing on skin purely by sensation of touch

Front 44

stereognosis

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ability to recognize form of objects by touch

Front 45

barognosis

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ability to tell relative weights

Front 46

combined cortical sensations

Back 46

use info from touch and proprioception;

stereognosis and barognosis

Front 47

receptor specificity

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receptors respond to 1 type of energy and 1 type of stimulus

Front 48

receptive field

Back 48

of sensory neuron is region of space in which presence of stimulus will alter firing of that neuron

Front 49

t/f: distal receptors tend to smaller than proximal + greater density of receptors

Back 49

true

Front 50

tonic receptors

Back 50

respond as long as stimulus is applied- sustained

Front 51

phasic receptors

Back 51

adapt to constant stimulus and stop responding- brief

Front 52

mechanoreceptors

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respond to mechanical deformation of receptor by touch, pressure, stretch, or vibration; mediate sense of touch, proprioceptive sensations

Front 53

chemoreceptors

Back 53

involved in senses of pain, itch, and respond to chemicals released by cells including damaged cells post-injury ... pain

Front 54

thermoreceptors

Back 54

in skin sense body temp and also changes in temp, temp of ambient air, objects that we touch

Front 55

nociceptors

Back 55

subset of each type of 3 receptors types that are specifically responsive to stimuli that threaten or damage tissue- noxious

Front 56

receptors of touch

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mechanoreceptors

Front 57

_____ receptors to skin deformation

Back 57

superficial dermis receptors

Front 58

merkel's discs

Back 58

pressure, fine touch

Front 59

meissner's corpuscles

Back 59

respond to skin deformation and are sensitive to light touch and vibration

Front 60

hair follicle receptors

Back 60

respond to hair displacement

Front 61

types of superficial dermis receptors

Back 61

merkel's discs, meissner corpuscles, hair follicle receptors

Front 62

deep dermis/subcutaneous fine touch receptors

Back 62

info about larger surface areas

Front 63

types of deep dermis/subcutaneous fine touch receptors

Back 63

ruffini endings, pacinian corpuscles

Front 64

ruffini endings

Back 64

detect skin stretch; contribution to proprioception

Front 65

pacinian corpuscles

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info regarding touch and vibration; contribution to proprioception

Front 66

course touch is mediated via ___ throughout skin

Back 66

free nerve endings

Front 67

thermoreception

Back 67

ability to sense relative temp and temp changes but not absolute temp

Front 68

adapt to maintained temp (types of nerves)

Back 68

free nerve endings

Front 69

specific nociceptors

Back 69

free nerve endings which respond to one type of noxious stimulus; respond to high intensity noxious mechanical, thermal, and chemical stimuli; localized pain sensations which are transmitted rapidly via myelinated A-delta fibers- fast sharp pain

Front 70

polymodal nociceptors

Back 70

not specific and respond to any high-intensity mechanical stimuli, chemical stimuli, and thermal stimuli; slow transmission of poorly localized pain occurs via unmyelinated C fibers and pain sensation replaced w/ long lasting burning pain

Front 71

receptors involved in proprioception

Back 71

muscle spindles, GTOs, joint receptors

Front 72

muscle spindles

Back 72

sensory organs of muscles; mechanorecptors buried in skeletal muscle = intrafusal fibers + sensory endings + motor endings

Front 73

respond to lengthening of muscle; muscle activation, rate of change in muscle length

Back 73

muscle spindles

Front 74

muscle spindle has what components

Back 74

2 types muscle fibers: extrafusal and intrafusal

2 types sensory afferents: Ia, IIb

2 types motor efferent fibers: alpha (stimulate extrafusal fibers) and gamma (stimulate intrafusal fibers)

Front 75

intrafusal fibers

Back 75

fusiform, inside fleshy part of skeletal muscle; contractile only at ends; arrangement of nuclei defines 2 types of fibers: nuclear bag and nuclear chain

Front 76

annulospiral sensory endings

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endings of type Ia afferent neurons wrap around central region of each intrafusal fiber

Front 77

flower spray sensory endings

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endings of type II afferent neurons end on nuclear chain fibers

Front 78

gamma motor neurons

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fxn to maintain sensitivity of spindle stretch by firing and causing ends of intrafusal fibers to contract, allowing info to be generated even when muscle is slack

Front 79

when muscle is lengthened and intrafusal fibers stretched

Back 79

activity of Ia and II afferents to spinal cord where they branch

branch 1 = info about motion to higher centers via ascending tracts

branch 2 = interneuron to alpha motor neuron to extrafusal fibers to contract and prevent damage, and to antagonists to relax and allow contraction and to gamma motor neuron back to intrafusal fiber to keep it active and this sending signals continuously

Front 80

GTOs

Back 80

proprioceptive mechanoreceptors in skeletal muscles at musculotendinous jxns and provides info about muscle tension and fxn to inhibit muscle in response to excessive tension

Front 81

GTOs arranged in ___ btw muscle fibers and collagen of tendons

Back 81

series

Front 82

what type of afferents neurons in GTOs

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Ib afferent

Front 83

GTO records what info

Back 83

change in tension and rate of change of tension and sends to post horn of SC

info to alpha motor... inhibitory to contracting muscle, excitatory to antagonist

Front 84

types of joint receptors

Back 84

ligament receptors

ruffini endings

pacinian corpuscles

free nerve endings

Front 85

joint receptors

Back 85

respond to mechanical deformation of ligs and capsules

Front 86

ligament receptors

Back 86

type Ib afferents respond to tension

Front 87

ruffini endings (jt receptors)

Back 87

in capsule respond to extremes of joint ROM; passive > active

Front 88

pacinian corpuscles (jt receptors)

Back 88

respond to mvmt

Front 89

free nerve endings in jt receptors

Back 89

responds to chemical stimulus in inflammation

Front 90

proprioception especially helpful in detecting

Back 90

size, shape, weight of object

Front 91

all sensory systems convey what 4 basic types of info when stimulated

Back 91

modality, location, intensity, timing

Front 92

sensory neurons

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afferent neurons; bringing info initiated in receptors in skin, skeletal muscles, tendons, joints; single myelinated or unmyelinated nerve fiber; made up of cell body and bifurcating axons

Front 93

A-beta nerve fibers

Back 93

carry info related to touch and conscious proprioception- large diameter myelinated fast conductors

Front 94

Ia (A alpha) Ib (A beta) , and II (A beta) nerve fibers

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carry info related to unconscious proprioception- large diameter myelinated fast conductors

Front 95

A-delta nerve fibers

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carry info related to fast pain and cool temp- medium myelinated rapid fibers

Front 96

C-nerve fibers

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carry info related to slow pain, warm temp and itch- small unmyelinated slow conductors

Front 97

peripheral neuropathy damage to peripheral nerve

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glove and stocking distribution

Front 98

diabetic neuropathy

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microvascular damage; insufficient supply to peripheral nerves

Front 99

chemotoxic neuropathy

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toxic damage to peripheral nerves

Front 100

alcoholic neuropathy

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toxic damage to peripheral nerves and nutritional deficits particularly thiamine deficiency

Front 101

damage/trauma/disease to/of spinal nerve

Back 101

sensory loss in dermatome distribution

Front 102

primary/first order neurons

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all sensory info travels in these neurons from periphery to spinal cord; cell bodies outside SC in DRG; enter SC posteriorally via dorsal roots and rootlets

Front 103

grey matter of SC, dorsal horn

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dorsal horn; sensory area

Front 104

white matter

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ascending tracts; sensory info from periphery to brain in dorsal and lateral white matter

Front 105

grey matter in SC arranged in

Back 105

lamina (Rexed lamina)

Front 106

Rexed lamina

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divisions by fxn and sensory info arrives at specific areas/laminae

Front 107

rexed lamina II

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substantia gelatinosa; important in modulation of pain sensation

Front 108

rexed lamina III and IV

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aka nucleus proprius; conscious proprioception and touch

Front 109

unconscious proprioception route

Back 109

spinal nerves entering at T1-L2 to dorsal horn to Clarke's nucleus to posterior spinocerebellar tract to cerebellum

Front 110

t/f: While wefollow the large projection neurons from the periphery to the brain, there aremany interneurons at each level of the spinal cord for intercommunication

Back 110

true

Front 111

Within the CNS a bundle of axons with the sameorigin and a common termination is called a

Back 111

tract

Front 112

projection neurons

Back 112

The tracts (pathways) only describe thoseneurons with long axons connecting distant areas of the body.

Front 113

conscious pathways

Back 113

fine/discriminative touch and proprioception; pain and temp (anterolateral pathways); crude touch and pressure

Front 114

fine/discriminative touch and proprioception pathway

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dorsal columns to medial leminiscus to thalamus to cortex

Front 115

pain and temp pathway

Back 115

anterolateral pathways

Front 116

fast pain pathway

Back 116

spinothalamic pathway; thalamus and brain

Front 117

slow pain pathway

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multiple pathways: spinoreticular, spinolimbic, spinomesencephalic pathways to midbrain, reticular formation, amygdala, multiple cerebral cortical areas (divergent relay pathways)

Front 118

crude touch and pressure pathway

Back 118

venterolateral pathway; thalamus and brain

Front 119

unconscious pathways

Back 119

unconscious proprioception via spinocerebellar pathways to cerebellum