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Neuro Exam 1 > Ascending Spinal Pathways > Flashcards

Flashcards in Ascending Spinal Pathways Deck (40):
1

anatomical types of receptors

free nerve endings - pain
encapsulated - touch, mechanical
special neural receptor cells - special/chemical senses

2

functional types of receptors

mechanoreceptors
nociceptors
photoreceptors
chemoreceptors
thermoreceptors

3

adequate stimulus

most appropriate stimulus that will allow receptor to pass current

4

modality

the sense it carries

ex/ stimulus = light
modality = vision

5

receptor potential

proportional to strength of stimulus
-graded potential

at threshold - primary afferent produces action potential

6

pre-cenral gyrus

primary motor cortex

7

post-central gyrus

primary somatosensory cortex

8

brodmans areas post central gyrus?

3, 1, 2
somatosensory

9

brodmans area for pre-central gyrus?

4
motor

10

targets for somatosensation

reflex arc
reticular formation
hypothlamus > limbic system
thalamus > cerebral cortex
cerebellum

**divergence of neurosystem

11

labeled line code

if you stimulate this tract
-modality of this tract results in certain sensation being felt

codes modality

12

population code

as intensity increases
number of receptors activated increased

13

frequency code

as intensity increases - rate of APs increases

14

receptor field

part of environment to which neuron responds

15

resolution

ability to distinguish between 2 separate stimulus

low density - large receptive field - less resolution
-few number of neurons in cortex
high density - small receptive field - more resolution
-larger number of neurons in cortex

16

large receptive field

lower density
lower resolution
fewer number of neurons in cortex

17

general proprioception

static position sense - know where is in space
kinesthesia - feeling movement

18

axons of PCML

A-alpha

large diameter, myelinated - fast

19

joint receptors

joint angle and tension in joint capsule

20

golgi tendon organs

sense tension in organs

21

muscle spindles

in extrafusal fibes
-detect change in muscle length

22

skin mechanoreceptors

also signal in proprioception

23

proprioceptors

joint receptors
golgi tendons
muscle spindles
skin mechanoreceptors

24

discriminative touch

high degree accuracy in location

ex/ graphesthesia / stereognosis

25

vibration

often tested with tuning fork

26

sensory ataxia

without coordination
-lack of proprioception

dysmetria - incorrect metering

wide base stance
truncal sway
difficult turning
inaccuracy in voluntary movements

27

anterolateral system

nociception, temp, crude touch
4 tracts

28

region of tracts of ALS

in anterior and lateral funiculi
-anterolateral region of cord

29

spinothalamic tract

conscious of ALS
projects to primary somatosensory cortex

primarily from somatic structures

30

tracts of anterolateral system

spinothalamic
spinoreticular
spinomesencephalic
spinohypothalamic

31

spinoreticular tract

projects to reticular formation
-alerts our attention to painful stimulus
-focus attention
-some autonomic tract

32

reticular formation

loose group of nuclei in core of brainstem, from medulla to dicencephalon

33

spinomesencephalic tract

to periaqueductal grey
pain modulation
-descend spinal cord

34

spinotectal tract

subset of spinomesencephalic tract

"visual grasp reflex"

35

spinohypothalamic tract

coordinate autonomic response to stimuli
-feel nausea with intense pain

36

emotional response to pain

RF and hypothalamus > limbic system

spinoreticular and spinohypothalamic tract

37

axons of anterolateral system

A-beta
A-delta and C

lightly or unmyelinated
small-medium diameter
-slower conducation

38

A-beta axons

touch and temperature
anterolateral system

39

A-delta and C fibers

pain
anterolateral system

40

C-fibers

unmyelinated