Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro Endocrine 2 > Motor tracts > Flashcards

Motor tracts Flashcards

1
Q

upper motor neuron

A

arise and are contained within the cerebral cortex or brain stem

axons travel in desscending tracts and will synapse with LMN or interneurons of the spinal tract

Corticospinal tract, and the corticobulbar tract

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

Lower motor neurons

A

Directly innervate the skeletal muscle

Gamma motor neuron: medium sized myelinated, project to intrafusal fibers in muscle spindle

alpha motor neuron: large cell bodies and large myelinated axons, project to extrafusal skeletal muscle

Ex: Peripheral nerves and cranial nerves

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

Corticospinal tract pathway

A

Direct pathway ( from cerebral cortex to spinal cord and out to muscles)

Medial corticospinal tract: postrual muscles (not clinically significant 10 percent of fibers)

Lateral corticospinal tract: limb muscles and fractination
-90percent of fibers

Pathway:
-Cell bodies arise in the cortex
-Descends from the cortex through the posterior limb of the internal capsule
-Continues through the cerebral peduncles, anterior pons, Pyramids
-fibers deccusate in the pyramids in the lower medulla (decusation of the pyramid)
descends the lateral column of the spinal cord and will synapse on the LMN

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

Voluntary motor control

A

Primary Motor cortex (brodmanns area 4)

  • Precentral gyrus
  • initiates voluntary mvmt
  • other supplementary motor area and premotor cortex give input to the primary motor cortex as well

similar somatotopographic distribution to somatosensory: Feet medial, arms hand middle, face is lateral

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

How does the corticospinal tract ascend from the cortex and what is its blood supply in this structure

A

Posterior limb of the internal capsule

  • anterior=Arms
  • posterior= legs

blood supply: lenticulostriate arteries

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

What travels in the sublenticular limb of the internal capsule

A

Auditory radiation

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

What travels in the Retrolenticular limb of the internal capsule

A

Optic radiation

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

Where does the Corticospinal tract travel in the midbrain and whats its blood supply

A

Posterior Cerebral A (P1)

and in the middle 1/3 of the Cerebral peduncle

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

Where does the corticospinal tract travel in the pons and what is its blood supply

A

Found in the anterior pons with the pontine nucleus and fibers around it

Paramedian branch of the basilar artery

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

Where does the corticospinal tract travel in the medulla and what is its blood supply

A

found in the pyramid where it will decussate at the caudal medulla

Anterior spinal artery specifically the sulcal branch

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

Where does the corticospinal tract travel in the spinal cord and what is its blood supplyy

A

Posterolateral region in the lateral corticospinal trct

the Arms (medial portion of the tract) get blood supply by the anterior spinal artery

the legs (lateral portion of the tract) get blood supply by the posterior spinal A

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

Where does the UMN synapse in the spinal cord

A

on the ventral horn with the LMN

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

What travels in the medial Corticospinal tract

A

Controls postrual and proximal movements of the neck, shoulder and trunk muscles

has the same pathway as the corticalspinal tract until the medulla it does not cross and will travel in the medial corticospinal tract
(only 10 percent of the fibers travel this route)

blood supply will be the anterior spinal A

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

what is the somatotopographic organization all the way down the Corticospinal tract

A

cortex: legs medial and hand lateral

cerebral peduncle: legs anterior and lateral, hand posterior and medial

pons: legs lateral, hand medial
medulla: legs lateral, hand medial

spinal cord: legs lateral, hand medial

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

What is the Corticobulbar tract and what does it carry

A

also called corticonuclear

arises from ventral part of the cortical area 4

descends brain stem and influences muscels innervated by cranial nerves including motor nuclei:

Trigeminal
Facial
glossopharyngeal
vagus
spinal accessory
hypoglossal

axons will decussate and control muscles on contralateral side

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

Where does the corticobulbar tract travel in the internal capsule, and in the midbrain , pons, and medulla

A

the genu

just medial to the corticospinal tract in the cerebral peduncle

in the anterior pons

and in the pyramids

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

Location of the CN V, VII, IX, X, XII, XI in the brain stem

A

pons: V, VII
medulla: IX, X, XII

spinal cord: XI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What type of input: ipsilateral, contralateral, bilateral does each CN recieve: V, VII, IX, X, XI, XII

A

V: bilateral input

VII: bilateral forehead
contralateral lowerface

Muscles of the palate: contralateral

  • Uvula will deviate in lesion
  • ipsilateral to UMN damage
  • Contralateral LMN damage

Muscles of the tongue: Contralateral

  • tongue protruds in a lesion
  • contralateral to UMN damage
  • ipsilateral to LMN

Accessory: Ipsilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

LMN topographically organization of the ventral horn

A

Medial LMN project to axial muscles
Lateral LMN project to limb muscles

LMN innervating the flexors are tend to be posterior
LMN innervating the extensors tend to be anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Indirect pathways: Medial UMN tracts

A

Tectospinal tract
Medial reticulospinal tract
Lateral vestibulospinal tract
medial vestibulospinal tract

These go to activate antigravity axial muscles

21
Q

Indirect pathways: Lateral UMN tracts

A

Rubrospinal tract
Lateral reticulospinal tract

To activate antigravity LMN of limb muscles

22
Q

Lateral vestibulospinal tract

A

Vestibular nuclei to spinal cord

Ipsilateral LMN
Innervating postural muscles of Limb extensors against gravity

23
Q

Medial Vestibulospinal tract

A

Vestibular nuclei to spinal cord

to cerviical and thoracic (neck and shoulder muscles)
coordination of head movements

24
Q

Medial (pontine) Reticulospinal tract

A

Pontine reticular formation to spinal cord
ipsilateral

Ipsilateral LMN innervating postural extensors and postural reflexors

25
Q

Lateral (medullary) reticulospinal tract

A

Medullary reticular formation to spinal cord
ipsilateral

Facilitates flexor motor neurons and inhbits extensor motor neurons
(innhibit of spinal segmental reflexes)

26
Q

Rubrospinal tract

A

Red nucleus to spinal cord
contralateral

innervates upper limb flexors

27
Q

Tectospinal tract

A

superior colliculus to upper spinal cord
contralateral

to neck muscles to help with coordination of the head with eye movements

28
Q

Corticospinal tract

A

Fine motor control of hand and limbs
motor neuron recruitment to increase force
inhibition of postural reflexes

29
Q

Corticobulbar tract

A

control muscles of face, chewing, speech, nd swallowing

30
Q

What happens if their is a LMN lesion

A

Flaccid paralysis
Wasting or atrophy
Hyporeflexia or areflexia due to denervation
hypotonia - decreased muscle tone
Denervation hypersensitivity - fasciculations

31
Q

Upper motor neuron signs or lesion

A

direct: loss of distal extremity strength and dexterity
babinski sign

indirect:
Hypertonia
Spasticity: rate dependant resistance, with collapse of the resistance at the end of the range of motion: clasp knife phenomenon
Rigidity: not rate or force dependant, constant throughout range of motion
Hyperflexia: may see clonus
Pronator drift

32
Q

either UMN or LMN will tell you the exact level of the lesion?

A

LMN

33
Q

If the UMN lesions at or above the lower medulla what side will the clinical signs be on

A

contralateral

34
Q

if the UMN lesions at the level of the spinal cord what side will the clinical signs be on

A

ipsilateral

35
Q

What is affected when a paitent presents with decorticate posture

A

lesion above the level of the red nucleus, usually includes the midbrain

thumb tuucked under flexed fingers in a fist position, pronation of forearm, flexion at elbow with lower extremity extension with foot inversion

36
Q

what is affected when a paitent presents with decerebrate posture

A

Lesion below red nucleus but above reticulospinal and vestibulospinal nuclei

upper extremity in pronation and extension and the lower extremity in extension

37
Q

spinal shock mirrors what type of lesion characteristics

A

LMN lesions

38
Q

hemisection of the spinal cord

A

Also called Brown-sequard syndrome

pain and temp from contralateral side of body loss 2 segments below the lesion

Discriminative touch and proprioception on ipsilateral

LMN signs at level of lesion: flacid paralysis

UMN signs on ipsilateral side of lesion

39
Q

Syringomyelia

A

Formation of a cyst within the spinal cord
Pain and temp affected first
-Anterior white commissure resulting in cape like deficit area

Motor loss:

  • May have LMN signs if Ventral horns are affected
  • May have UMN signs if lateral corticospinal tract is affected

Highly correlated with Chiari I

40
Q

Anterior cord syndrome

A

Compression or damage to anterior part of spinal cord
-usually due to spinal cord infarction, intervertebral disc herniation and radiation myelopathy

  • also can have damage to anterior spinal A
  • Lose bilateral Corticospinal tract, ALS and Anterior fasciculus
41
Q

Central cord syndrome

A

Compression and damage of central spinal cord

caused by usually cervical hyperextension

symptoms similar to syringomyelia

42
Q

Medial medullary syndrome

A

usually an issue with the Anterior spinal Artery

Pyramid is affected= contralateral UMN damage
Medial Lemniscus= contralateral vibration, proprioception, and Discriminative touch is loss
Hypoglossal nucleus = LMN problems so the tongue will potray towards the lesion

Dejerine syndrome

43
Q

Lateral Medullary syndrome

A

usually arise with loss of Posterior Inferior Cerebellar Artery

Wallenberg syndrome

ALS = Contralateral Pain and temp to the body
Spinal trigeminal nucleus = ipsilateral Pain and temp to the face
Nucleus ambiguus= ipsilateral hoarseness and swallowing issue, uvula deviate away from lesion
Vestibular nuclei = dizziness and nausea
Restiform body = ataxia and wide base gate
Hypothalamicspinal tract = ipsilateral horners syndrome

44
Q

Central Seven Palsy

A

lesion to the corticobulbar tract involving the CN VII

muscles of the upper face are controlled by bilateral so no deficits there

muscles of the lower face are controlled contralateral so there will be drooping of muscles at the corner of the mouth on the contralateral side of the lesion

45
Q

Bells palsy

A

LMN damage causing ipsilateral flaccid paralysis of upper and lower face

46
Q

Weber syndrome

A

supplied by the Posterior Cerebral Artery P1

in the midbrain

Corticospinal tract = contralateral UMN problems

Corticobulbar tract = Contralateral facial drop

Oculomotor N = dilated pupil and eye looks down and out

47
Q

Spastic Cerebral palsy

A

Movement dysfunction :

  • abnormal sypraspinal influences
  • failure of normal neuronal selection
  • consequent aberrant muscle development

Motor disorders:

  • Paresis
  • Abnormal tonic stretch reflexes, both at rest and during movement
  • Reflex irradiation
  • lack of postural preperation prior to movement
  • abnormal cocontraction of muscles
48
Q

Amyotrophic Lateral Sclerosis (ALS)

A

Lou Gherigs disease

Destroys only the somatic motor neurons:
-UMN and brainstem and spinal cord LMN

Leads to Paresis, myoplastic hyperstiffness, hyperreflexia, babinskis sign, atrophy, fasciculations and fibrillations

Cranial nerve involvement leads to difficulty breathing swallowing and speaking

49
Q

Polyneuropathy

A

involvement of sensory motor and autonomic

progressing from distal to proximal

due to dying back or impaired axonal transport

demyelinization may also contribute

glove and stocking

Neuro Endocrine 2 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions