Ascending an Descneding pathways Flashcards

1
Q

what type of neurons does the ventral column contain

A

motor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what type of neurons does the dorsal column contain

A

sensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the ascending pathways

A

SENSORY
dorsal column/medial leminiscus system
spinothalamic tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the descending pathways

A

MOTOR

pyramidial and extra-pyramidial tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the extra-pyramidial tracts

A

tectospinal tract
reticulospinal tract
vestibulospinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what sensory modalities are controlled by dorsal column medial leminiscus tract

A

fine touch

proprioception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what sensory modalities are controlled by spinothalamic tract

A

pain, temperature and deep pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how do first order axons enter spinal cord for DCML

A

through dorsal root and travel up dorsal column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

where do first order neurons terminate in DCML tract

A

medulla oblongata - nucleus gracilis and nucleus cutaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where do fibres for DCML cross the midline and where do they go

A

medulla oblongata - 2nd order neurons

travel up medial leminiscus tract (pons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are 2nd order neurons in DCML called

A

internal arcuate fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where do 2nd order neurons from DMCL terminate

A

ventral posterolateral thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where do 3rd order DCML project to

A

parietal cortex in somatotopic arrangement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do PNS sensory fibres enter spinothalamic tract

A

through dorsal root to dorsal column

terminate in posterior aspect of dorsal horn (substantia gelatinosa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what happens to 2nd order neurons in spinothalamic tract

A

they decussate in spinal cord (cross midline)
travel up spinothalamic tract (anterior column)
then through lateral/spinal leminiscus (pons)
terminate at thalamus (posterolateral nucleus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

where do 3rd order neurons in spinothalamic tract project to

A

ipsilateral primary sensory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the function of the pyramidial tracts

A

voluntary movement of musculature of face and body

18
Q

what are the function of extra-pyramidial tracts

A
involuntary control of all musculature:
posture
balance
tone 
locomotion
19
Q

where do pyramidial tracts originate

A

cerebral cortex

20
Q

where do extra-pyramidial tracts originate

A

brain stem

21
Q

where are upper motor neurons found

A

CNS
cell body in brain stem or cerebral cortex
axons remain in CNS

22
Q

what are the 2 pyramidial tracts

A

corticospinal

corticobulbar

23
Q

where do fibres of corticospinal tract originate from and travel to

A

originate from pre-motor cortex, primary motor cortex and somatosensory area
travel through internal capsule

24
Q

where is internal capsule

A

between basal ganglia and thalamus

25
Q

what is internal capsule susceptible to and what is the clinical relevance of this

A

compression from haemorrhagic bleed

may cause lesion of descending pathway

26
Q

where does the corticospinal tract divide into 2, and what are the 2 divisions called

A

medulla

lateral and anterior

27
Q

what happens to lateral corticospinal tract

A

decussates in medulla (crosses midline)
descends in spinal cord terminating in ventral horn
LMN supplies muscles of body

28
Q

what happens to anterior corticospinal tract

A

remains ipsilateral when travelling down spinal cord

decussate (cross midline) and terminate in ventral horn of CERVICAL and UPPER THORACIC segments

29
Q

where do upper motor neurons of corticobulbar tract terminate

A

on motor fibres of cranial nerves

30
Q

from the extra-pyramidial tracts, which one does decussate (cross midline)

A

tectospinal

31
Q

where does tectospinal originate

A

midbrain - superior colliculus

32
Q

what does superior colliculus receive input from

A

optic nerve

33
Q

what is the function of the tectospinal tract

A

control movements of head and neck in relation to visual stimulus

34
Q

where do UMN from tectospinal tract decussate and terminate

A

decussate in midbrain

terminate in cervical segment of spinal cord

35
Q

where does vestibulospinal tract originate

A

vestibular nuclei of pons and medulla

36
Q

where do vestibular nuclei receive input from

A

organs of balance

37
Q

what is the function of vestibulospinal tract

A

controls anti-gravity muscles to maintain posture and balance

38
Q

what are the anti gravity muscles

A

flexors of arms

extensors of legs

39
Q

what are the two reticulospinal tracts and where do they originate

A

medial - pons

lateral - medulla

40
Q

function of medial reticulospinal tract

A

facilitates voluntary movements

increases muscle tone

41
Q

function of lateral reticulospinal tract

A

inhibits voluntary movements

decreases muscle tone