5. Somatosensory system 1

Question 1

Damage to peripheral/central components of NS can result in which 3 diseases?

Answer 1

1. Neuropathy
2. Neuralgia
3. Phantom Limbs

Question 2

what is neuropathy?

Answer 2

disease/dysfunction of peripheral nerves - causes numbness and weakness

Question 3

what is neuralgia?

Answer 3

intense, intermittent pain along course of nerve

Question 4

common place for neuralgia?

Answer 4

head/face

Question 5

what do peripheral nerves innervate?

Answer 5

skin and deeper tissues

Question 6

what are primary/sensory afferents?

Answer 6

axons which carry info from somatic receptors

Question 7

where do primary/sensory afferents enter the spinal cord?

Answer 7

spinal nerve + dorsal root

Question 8

where do motor efferents leave the spinal cord?

Answer 8

via spinal nerve and ventral root

Question 9

what are motor efferents?

Answer 9

axons which travel from spinal cord to periphery

Question 10

what is a ganglion?

Answer 10

group of neuronal cell bodies which lie outside CNS

Question 11

what lies in the grey matter of spinal cord?

Answer 11

ventral and dorsol horn

Question 12

what columns lie in the white matter of spinal cord?

Answer 12

lateral
antero-lateral
ventral
dorsal

Question 13

4 segments of spinal cord

Answer 13

cervical
thoracic
lumbar
sacral

Question 14

Name for chicken pox

Answer 14

herpes zoster virus

Question 15

where can chicken pox lie after someone has been affected?

Answer 15

primary sensory neurones

Question 16

what can chicken pox reactivate as in adult life?

Answer 16

shingles

Question 17

the different segments of the spinal cord are linked to…. …. (2 words)

Answer 17

skin dermatomes

Question 18

symptoms of shingles

Answer 18

inflammation and blistering of skin

Question 19

4 different types of sensation receptor ?

Answer 19

tactile
proprioception
thermal
nociceptive

Question 20

which receptor detects fine touch, pressure and vibration?

Answer 20

tactile

Question 21

what receptor detects painful stimuli?

Answer 21

nociceptive

Question 22

what does proprioception receptors detec?

Answer 22

info about position and movements

Question 23

which 2 receptors are low threshold mechanoreceptors?

Answer 23

tacitile and proprioception

Question 24

4 types of tactile receptors

Answer 24

Merkel-disc
pacinian corpuscle
meissner corpuscle
ruffini corpuscle

Question 25

what 3 things are mediated by proprioception?

Answer 25

muscle spindles
golgi tendon organs
joint receptors

Question 26

why are there polymodal nociceptors?

Answer 26

they detect more than one stimuli - such as mechanical and thermal

Question 27

what are meissner corpuscles?

Answer 27

looping axonal terminals which intertwine supporting cells

Question 28

which corpuscle is surrounded by fluid filled capsule and has an onion shaped appearance?

Answer 28

pacinian

Question 29

what are ruffini endings?

Answer 29

nerve terminals intertwined with collagen fibres

Question 30

which receptors are free nerve endings that penetrate epithelial cells?

Answer 30

nociceptors

Question 31

what is speed of adaption?

Answer 31

how quickly a receptor responds to stimuli

Question 32

describe slow acting receptors

Answer 32

1. slow response

2. sustained response when stimuli removed

Question 33

describe rapid acting receptors

Answer 33

1. rapid response

2. no sustained response when stimui removed

Question 34

which receptors are slow acting?

Answer 34

ruffini’s endings + merkel’s discs

Question 35

which receptors are fast acting?

Answer 35

pacinian and meissners corpuscles

Question 36

which 2 receptors have a large receptive field?

Answer 36

pacinian corp + ruffini endings

Question 37

which 2 receptors have a small receptive field?

Answer 37

Meissner’s corpuscles + Merkel’s discs

Question 38

where in the skin are pacinian corp located?

Answer 38

Deep dermis

Question 39

where in the skin are Mesissner corp located?

Answer 39

Below epidermis - dermal papillae

Question 40

freq of vibrations detected by pacinian corp

Answer 40

high 250-250 Hz

Question 41

freq of vibrations detected by Meissner corp

Answer 41

low 30-50 Hz

Question 42

which corp detects fine texture and which detects rough texture

Answer 42

fine - pacinian

rough - meissner

Question 43

which type of receptors are important for sensation and feedback?

Answer 43

rapid acting

Question 44

where are ruffini endings?

Answer 44

deep dermis

Question 45

where are merkel’s discs?

Answer 45

epidermal/dermal border

Question 46

which receptor detects shapes, rough edges, borders, texture?

Answer 46

Merkel’s discs

Question 47

Which receptor detects stretching, indentaton?

Answer 47

Ruffini endings

Question 48

Hair follicles are a type of mechanoreceptor. Where are they located and what do they detect?

Answer 48

• dermis + epidermis

- movements across skin

Question 49

which receptors are best suited for braille encoding and why?

Answer 49

Merkel’s discs

1. high temporal resolution
2. high spatial resolution

Question 50

why are some areas in the body more sensitive to touch than others? i.e. can discriminate between 2 different points?

Answer 50

more sensory receptors

Question 51

areas of high sensitivity

Answer 51

fingertips, face

Question 52

areas of low sensitivity

Answer 52

torso, limbs

Question 53

what detects muscle stretch?

Answer 53

muscle spindles

Question 54

what detects muscle tension?

Answer 54

golgi tendon organs

Question 55

which causes inhibition of muscle contraction (relaxation)?

Answer 55

golgi tendon organ

Question 56

describe diameter + conducting speed of nocireceptors and thermoreceptors

Answer 56

• small diameter

- slow conductors

Question 57

describe diameter + conducting speed of touch and proprioception receptors?

Answer 57

• large diameter

- fast conductors