Somatosensory pathways and receptors (Dr. Duas) Flashcards Preview

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Flashcards in Somatosensory pathways and receptors (Dr. Duas) Deck (64):
1

What are the two types of cutaneous receptors for conscious proprioception

rapidly adapting and the slowly adapting receptors

2

function of rapidly adapting receptors

respond to application and removal of the stimulus but NOT during maintained stimulation

3

function of slowly adapting receptors

active as long as the stimulus is present

4

merkels disk senses

pressure

5

paccinian corpuscle senses

vibration

6

meissner's corpuscle senses

tactile impulse

7

ruffini's endings sense

pressure

8

pathway for conscious proprioception from the limbs and the trunk ?

PCMLS pathway

9

Pathway for PCMLS pathway

Primary afferent
fasiculus cuneatus/fasciculus gracilis-->fasiculus cuneate nuclei within the medulla-->medial lemniscus-->VPL of thalamus

10

fasciculus gracillis

sacral, lumbar and lower thoracic levels

11

fasciculus cuneatus

upper thoracic and cervical levels

12

in the alternative PCMLS pathway where do the synapses occur

lamina II and IV, as well as the typical cuneatus nuclei and gracillis nuclei

13

what provides conscious proprioception from the head

anterior and posterior trigeminothalamic tracts

14

describe the posterior trigeminothalamic tract

synapses in principal nucleus and ascends via the PTTT (does NOT cross the midline) to VPM

15

describe the anterior tigeminothalamic tract

principal nucleus, crosses midline and ascends via ATT to VPM

16

where is the primary central cortex located ?

post central gyrus

17

if you have lesion in area 1 of the PSC what do you lose ?

loss of texture and discrimination

18

if you have a lesion in area 2 of the PSC what do you lose ?

loss of size and shape discrimination

19

what is asterogenesis

loss of size and shape

20

if you have a lesion in area 3b of the PSC what do you lose?

diminished texture discrimination and asterogenesis (loss of size and shape)

21

cutaneous receptors are found where in PSC

3b and 1

22

proprioceptive receptors are found where in PSC

3a and 2

23

where is the second somatosensory cortex found (SII)

inner face of the upper bank of the lateral sulcus

24

the secondary somatosensory cortex is supplied by

middle cerebral artery

25

lesion of the posterior spinal artery leads to injury to what

posterior columns (PCML pathway)

26

lesion of the anterior spinal artery would injury what

medial lemniscus (PCML pathway)

27

lesion of the thalamogeniculate branches of the posterior cerebral artery would result in injury to

VPL and VPM

28

injury to the anterior and middle cerebral arteries would injury the

primary sensory cortex

29

lesion to the basilar and superior cerebellar arteries would result in injury to

basilar and superior cerebellar arteries

30

what are the two pathways for nonconscious proprioception ?

spinocerebellar pathway
trigeminocerebellar pathway

31

spinocerebellar pathway functions to

sensory information from the limbs and the trunk

32

trigeminocerebellar pathway functions to

sensory information from the head

33

nonconscious proprioception to lower limb

anterior spinocerebellar tract
posterior spinocerebellar tract

34

nonconsciocus proprioception to the upper limb

rostral spinocerebellar tract
cuneocerebellar tract

35

which two spinocerebellar pathways are mostly mechanoreceptors

anterior spinocerebellar
rostral spinocerebellar

36

what is friedrich ataxia

congenital autosomal recessive disease-degeneration of the spinal cord pathways including spinocerebellar tracts leading to lack of coordination during walking and other movements

37

where do the primary afferent fibers synapse in the spinocerebellar tract

posterior tract-dorsal nucleus of clark (lamina 7-T1-L2)
anterior tract- lamina 5, 8, spinal border cells of L3-L5

38

which part of the tracts for lower limb of the spinocerebellar tracts are mostly cutaneous mechanoreceptors

anterior spinocerebellar tract

39

which tract of the spinocerebellar tracts cross the midliine

anterior spinocerebellar tract (anterior commissure)

40

the spinocerebellar tracts enter the _________before they ascend into the lateral cerebellar vermis

restiform body (the rostral spinocerebellar tract also enters the cerebellar peduncle)

41

where does the rostral spinocerebellar tract synapse before ascending up the spinal cord

lamina VII (C4-C8)

42

Describe the Pathway of the cuneocerebellar tract ?

primary afferent fibers ascned via the cuneocerebellar tract and synapse in the lateral cuneate nucleus enter the restiform body and enter the medial cerebellar vermis (does not cross midline)

43

describe the pathway of the rostral spinocerebellar tract ?

primary afferent fibers synapse in lamina VII to anterior spinocerebellar tract through restiform body and cerebellar peduncle to the LATERAL cerebellar vermis (does NOT cross the midline)

44

what are the main pathways of protopathic sensibility

anterolateral system (spinothalamic and spinoreticular tract
spinocerbicothalamic tract
anterior trigeminothalamic tract

45

A-delta mechanical nociceptors

thinly myelinated fibers

46

C-polmodal nociceptors

nonmyelinated fibers

47

describe the spinothalamic tract

primary afferent fibers
synapse in lamina 1,5, and 2
cross at each segment at the anterior commissure
ascend via ALS
axon collaterals to the reticular formation
VPL of the thalamus

48

types of fibers in lamina 1 and 5

a delta fibers

49

types of fibers in lamina 2

c fibes

50

describe the spinoreticular tract

parimary afferent fibers in lamina II and III, interneurons 5, 8, cross at anterior commisure and ascend via anterolateral : spinoreticluar fibers and VPL of thalamus

51

where does the spinocervicothalamic tract synapse

limain III, IV, acsends and then lateral cervical nucleus and then crosses midline

52

protopathic for the head

ATT tract, synapses in spinal trigeminal nucleus and acsends via ATT and enters VPM

53

what is wallenberg syndrome

lesion of the posterior inferior cerebellar artery resulting in CONTRALATERAL loss of pain, temperature and crude touch over the body and ipsilateral loss over the face

54

rupture of arterila vasocorona between the ant. and post. spinal arteries would injur

spinal als

55

posterior inferior cerebellar artery would injure

medullary ALS and spinal trigeminal nucleus

56

injury to the thalamogeniculate branches of the posterior cerebral artery would injur

VPL and VPM

57

injury to the anterior and middle cerebral arteries would injur

primary sensory cortex

58

syringomyleIA

cystic cavitation of the central regions of the spinal gray matter; destruction of the decussating ALS fibers in the anterior commisure

59

where is pain perceived

at the subcortical levels

60

what pathway seems necessary to localize pain

spinothalamic pathway

61

what pathway is important for suffering component of the pain experience (some drugs like benzodiazepines can disrupt this component)

spinoreticular

62

VPL injury causes what type of pain

transient release of pain

63

VPM injury causes what type of pain

long lasting pain relief

64

function of enkephalingergic neruons

they suppress the activity of pain fibers