Ascending Spinal Pathways

Question 1

anatomical types of receptors

Answer 1

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

Question 2

functional types of receptors

Answer 2

mechanoreceptors
nociceptors
photoreceptors
chemoreceptors
thermoreceptors

Question 3

adequate stimulus

Answer 3

most appropriate stimulus that will allow receptor to pass current

Question 4

modality

Answer 4

the sense it carries

ex/ stimulus = light
modality = vision

Question 5

receptor potential

Answer 5

proportional to strength of stimulus
-graded potential

at threshold - primary afferent produces action potential

Question 6

pre-cenral gyrus

Answer 6

primary motor cortex

Question 7

post-central gyrus

Answer 7

primary somatosensory cortex

Question 8

brodmans areas post central gyrus?

Answer 8

3, 1, 2

somatosensory

Question 9

brodmans area for pre-central gyrus?

Answer 9

4

motor

Question 10

targets for somatosensation

Answer 10

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

**divergence of neurosystem

Question 11

labeled line code

Answer 11

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

codes modality

Question 12

population code

Answer 12

as intensity increases

number of receptors activated increased

Question 13

frequency code

Answer 13

as intensity increases - rate of APs increases

Question 14

receptor field

Answer 14

part of environment to which neuron responds

Question 15

resolution

Answer 15

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

Question 16

large receptive field

Answer 16

lower density
lower resolution
fewer number of neurons in cortex

Question 17

general proprioception

Answer 17

static position sense - know where is in space

kinesthesia - feeling movement

Question 18

axons of PCML

Answer 18

A-alpha

large diameter, myelinated - fast

Question 19

joint receptors

Answer 19

joint angle and tension in joint capsule

Question 20

golgi tendon organs

Answer 20

sense tension in organs

Question 21

muscle spindles

Answer 21

in extrafusal fibes

-detect change in muscle length

Question 22

skin mechanoreceptors

Answer 22

also signal in proprioception

Question 23

proprioceptors

Answer 23

joint receptors
golgi tendons
muscle spindles
skin mechanoreceptors

Question 24

discriminative touch

Answer 24

high degree accuracy in location

ex/ graphesthesia / stereognosis

Question 25

vibration

Answer 25

often tested with tuning fork

Question 26

sensory ataxia

Answer 26

without coordination -lack of proprioception dysmetria - incorrect metering wide base stance truncal sway difficult turning inaccuracy in voluntary movements

Question 27

anterolateral system

Answer 27

nociception, temp, crude touch | 4 tracts

Question 28

region of tracts of ALS

Answer 28

in anterior and lateral funiculi | -anterolateral region of cord

Question 29

spinothalamic tract

Answer 29

conscious of ALS projects to primary somatosensory cortex primarily from somatic structures

Question 30

tracts of anterolateral system

Answer 30

spinothalamic spinoreticular spinomesencephalic spinohypothalamic

Question 31

spinoreticular tract

Answer 31

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

Question 32

reticular formation

Answer 32

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

Question 33

spinomesencephalic tract

Answer 33

to periaqueductal grey pain modulation -descend spinal cord

Question 34

spinotectal tract

Answer 34

subset of spinomesencephalic tract "visual grasp reflex"

Question 35

spinohypothalamic tract

Answer 35

coordinate autonomic response to stimuli | -feel nausea with intense pain

Question 36

emotional response to pain

Answer 36

RF and hypothalamus > limbic system spinoreticular and spinohypothalamic tract

Question 37

axons of anterolateral system

Answer 37

A-beta A-delta and C lightly or unmyelinated small-medium diameter -slower conducation

Question 38

A-beta axons

Answer 38

touch and temperature | anterolateral system

Question 39

A-delta and C fibers

Answer 39

pain | anterolateral system

Question 40

C-fibers

Answer 40

unmyelinated