Neuroanatomy Flashcards
1
Q
Cranial nerves 2-12 are attached at the ___
A
Brainstem
2
Q
Alternating hemiplegias
A
Central brainstem lesions
3
Q
Motor cranial nuclei
A
VII, nucleus ambiguus
4
Q
Sensory spinal cord
A
Dorsal roots
Posterior columns
Lateral spinothalamic tract
Anterior white commissure
5
Q
Motor spinal cord
A
Lateral Corticospinal tract
Anterior horn
Lateral reticulospinal tract
6
Q
Brainstem sensory
A
Spinal lemniscus Medial lemniscus Trigeminal lemniscus Lateral meniscus Descending tract of V
7
Q
Brainstem motor
A
Corticospinal tract
Corticobulbar tract
8
Q
Brainstem special systems
A
Medial longitudinal fasci
9
Q
What does trauma to the head cause
A
Hematoma, herniation, hemorrhage’s
10
Q
Subdural hematoma
A
Bridging veins get displacement of the left cerebral hemisphere and midline shift..lateral ventricle enlarged
11
Q
Problem with 9 vs 10
A
9-oropharyngeal sensation:gag reflex
10-laryngoscopy, dysphonia, dysphagia
12
Q
9
A
Sensory gag
13
Q
10
A
Motor gags
14
Q
Phwhat innervates the pharynx
A
Pharyngeal plexus (in buccopharyngeal fascia)
15
Q
Sensory of pharyngeal plexus
A
GVA from the pharyngeal branch of glossopharyngeal nerve
16
Q
Pharyngeal plexus motor
A
SVE fibers from vagus
17
Q
What conveys afferent information from gag reflex
A
GVA fibers from pharyngeal plexus
18
Q
Branches of 9
A
Pharyngeal nerve to pharyngeal plexus
Sensory GVA to mucosa of post1/2 tongue and pharynx and sensory (SVA) to taste buds of post 1/3
Motor SVE to stylopharngeus muscle
19
Q
Spastic hemiplegic involves __ ___
A
Corticospinal tract
20
Q
Corticospinal tract
A
Upper motor neurons
21
Q
Lesion in Corticospinal tract
A
Contralateral spastic hemiplegia
22
Q
What is contralateral spastic hemiplegia
A
Hyperreflexia, hypertonia, paralysis, and disuse atrophy
23
Q
Lesion of ventral roots
A
Lower motor neuron paralysis
24
Q
LMN paralysis
A
Atonia, areflexia, fasciculation, flaccid paralysis
25
Supranuclear fascial palsy
Corticobulbar tract
26
Corticobulbar originates where
Int he head region of the precentral gyrus
27
What is the course of the Corticobulbar fibers
Through the gene of the internal capsule and cerebral peduncle as uncrossed CBT.
Decussate in lower pons (between I and VII) and descend in the lower brainstem as crossed CBT
28
Unilateral lesion of uncrossed CBT
Supranuclear facial palsy
29
Unilateral lesion of crossed CBT (below the decussation
Ipsilateral cranial nerve palsies
30
The __ quadrant of the face is unaffected by unilateral lesions of the Corticobulbar fibers
Upper
31
Unilateral lesion of the Corticobulbar fibers to the facial nucleus result in prarlysis of the __ __ __ of the face
Controlateral lower quadrant
32
Proprioceptice and 2 point tactile discrimination loss below L2 dermatomes indicates involvement of what
Fasciculus gracillis
33
Bilateral atonia, areflexia and flaccid paralysis involving C7-T1 motor dermatomes indicates involvement of which of the following
Anterior horn neurons
LOWER MOTOR NEURON PARALYSIS
34
Hemianalgesia and thermal hemianesthesia indicates involvement of what
Spinal lemniscus
35
Alternating hemianalgesia indicates involvement of which of the following
Descending tract V (8 and 12)
36
What causes alternating hemianalgesia
Lesion of the descending tract of V and the spinal lemniscus
37
CPA and Wallenberg syndrome
Have alternating hemianalgesia
38
Lesion of V
Complete anesthesia of the face and paralysis of the muscle of mastication
39
Bilateral diminution of hearing with a more prominent loss in one ear indicates involvement of what
Lateral lemniscus
40
Unilateral lesion of lateral lemniscus, inferior colliculus, brachium of the inferior colliculus and medial geniculate body result in
Bilateral diminution of hearing with a more prominent hearing loss in the contralateral ear
41
One horizontal gaze to the right, the left eye does not adductor and the right eye shows nystagmus indicators involvemtn of which
Medial longitudinal fasciculus
42
Left eye INO (intraocular opthalmoplegia)
Horizontal base to the left is normal, disturbances in gaze to the right
Gaze to the left shows no addition of left eye and nystagmus in right eye
43
Left internuclear opthaloplegia
Normal horizontal gaze to the left
| Disturbance in horizontal gaze to the right
44
With left INO why do we get normal horizontal gaze tot he left and not to the right
The oculomotor nucleus on the left and right abducens nucleus are not communicating so have no abduction on left and have nystagmus on right
45
What does the abducens nucleus mediate? What about the oculomotor
Abducens-lateral rectus
| Oculomotor-medial rectus
46
Left homonymous hemianopia indicates involvement of which of the following
Optic tract
47
Unilateral lesions of the lateral geniculate body, complete optic radiations or visual cortex result in ___ ___ ___
Contralateral homonymous hemianopsia
48
Left homonymous hemianopia would indicate a lesion on the _ visual pathway
Right (optic tract, lateral geniculate body or complete optic radiations)
49
Internal strabismus indicates involvement of what
Abducens nerve
50
CN1 injury
Specific olfactory challenges
51
CN2 injury
Visual fields, light reflexes, acuity
52
CN3 right
Cardinal signs of gaze
53
CN3 left
Complete ptosis, ext. strabismus, pupil dil
54
CNIV right
Cardinal signs of gaze
55
CN IV left
Inability to adduct and depress
56
CNVI right
Cardinal signs of gaze
57
CN6 left
Internal strabismus
58
CNVII
Muscles of facial expression
59
CNVIII
Unilateral impaired hearing
60
CNIX
Oropharyngeal sensation: gag reflex
61
CNX
Laryngoscopy, dysphonia, dysphagia
62
CNXI
Inability to shrug shoulder (trap) or flex or flex and rotate head opposite affected muscle (scm)
63
CNXII
Paralysis, fasciculataions, derivation of protruded tongue to affected side
64
Contralateral
Sensory or motor deficits occurring not he opposite side of the causative lesion
65
Lesion right motor cerebral cortec
Contralateral paralysis of the left side of body
66
Ipsilateral
Sensory of motor deficits occurring on the same side as the causative lesion
67
Destruction fo the posterior column of spinal cord on right side
Ipsilateral loss of proprioception and tactile discrimination fromt he right side of the body below the level of the lesion
68
Afferent
Sensory
69
Efferent
Motor
70
Somatotropin
Sensory or motor pathways convey their fibers in a highly organized laminated fashion as they ascend or descended to specific regions of the cortex
Parts of cortec, major sensory and motor(pyramidal)
71
Homunculus
Cartoon of exaggerated proportions of the cortical map
72
Fasciculus
Referring to a bundle of nerves
73
Tract
Fasciculus comprised of nerve fibers that have common origin, termination and function
74
Lemniscus
Crossed secondary nerve fibers in a conscious sensory pathway
75
Flax herniation
Cingulate gyrus herniate across the midline beneath the free edge of the falx
Ie midline shift
76
Tectorial or uncal herniation
Hernate cerebrum under falx cerebri and/or through the tentorial notch
77
Herniation of th uncus through the incisors compresses and displaces the ___
Midbrain
78
Bilateral compression of th midbrain reticular formation results in a progressive decrease int he level of _
Consciousness
79
Tonsillar herniation
Space expanding massies in posterior cranial fossa Macy abuse cerebellar tonsil to herniate through he foramen magnum which can compress the lower medulla.upper cervical spinal cord seen in Arnold chair I malformation
80
Expanding masses int he posterior cranial fossa may ___displace the superior portion of the cerebellum through the tentorial notch and compression the midbrain and related structures
Superiorly
81
Cranial nerve and nuclei lesions
Ok
82
Unilateral lesion spinal lemniscus
Contralateral hemianalgesia and thermal hemianesthesia. Loss of passive touch may be masked by the intact posterior columnmedial lemincasl system
Terminates VPL\\contraleral hemianalgesia BODY
83
Unilateral medial lemniscus
Maintains somatopic organization of its fibers throughout the brainstem. It ascends, the position of fibers from the upper and lower extremities rotate 90 degrees
-loss of proprioception, two point tactile discrimination and vibratory sensation on the opposite side of the body and limbs
84
Unilateral trigeminal lemniscus
Okascends adjacent to medial lemniscus in brainstem and terminated at VMP nucleus of dorsal thalamus
Conveys pain, temperature and crude tactile sensation from the opposite 1.2 of face. Located between medial lemniscus and spinal lemniscus
Trigeminal reticulothalmic pathway
C flow pain neurons from the subnucleus caudalis project bilaterally to the brainstem RF as trigeminoretuclar fibers.
85
Unilateral lateral lemniscus
Okconveys bilateral auditory information, predominantly to opposite ear. Located in lateral brainstem
Both dorsal and intermediate stria decussate I th e upper medulla and ascend into e contralateral lateral lemniscus
- auditory path
- complete deafness
- sudden loss of hearing BILATERAL diminution of hearing
- but more prominent loss to contralateral ear
86
Unilateral medial longitudinal fasciculus
Internuclear opthalmoplegia
Abnormal response to horizontal gaze int he direction opposite the side of the lesion
Unilateral-impairment or loss of adduction of ipsilateral eye and nystagmus of the abducting eye
87
Unilateral corticospinal lesion
Unilateral-contralateral spastic hemiplegic or spastic hemiparesis
Descends through the corona radiata, internal capsule, cerebral peduncle, pons and upper medulla. In lower medulla most decussate at pyramidal decussation and form LCST
LCST-descends in lateral funiculars . Most terminate in neuronal pools at all levels of spinal cord (spinal reflex circuits)
Unilateral LCST lesion-ipsilateral paralysis or paresis of the distal limb musculature innervated by those spinal segments below the level of the lesion
Anterior CTS-lesion little effect
88
Corticobulbar tract unilateral lesion
Arise from large pyramid ally shaped neurons of beta in primary and premotor cortices with CST
(Originate in head region of precentral gyrus..course through genu of internal capsule and cerebral peduncle as uncrossed CBT -unilateral lesions of uncrossed cause contralateral supranuclear facial palsy. The decussate in lower pons and descend in lower brainstem, unilateral lesions below decussation may cause some ipsilateral CN palsies)
Descending tracts
Lesion causes UMN paralysis
-spastic paralysis off the antigravity muscles (hypertonic, hyperreflexia, babinski sign, clonus and disuse atrophy)
-SUPRANUCLEAR FACIAL PALSY
89
Brainstem lesion: alternating hemiplegias variations
Lesion of descending tract of V
And spinal lemniscus
Part of CPA and Wallenberg
-lesio in five causes complete anesthesia of face and paralysis of muscles of mastication
90
Syndrome of PICA / Lateral Medullary SYndrome/Wallenberg
Displacement of the PICA on angiograms of the posterior cranial fossa may indicate the presence of a space occupying mass such as a tumor. Thrombosis of the PICA
Causes dysphagia, dysphagia, alternating hemianalgesia
Involved descending 5
- destruction fo the spinal lemniscus results in contralateral hemianalgesia
- destruction of the descending tract of V results in ipsilateral loss of pain and temperature sensations from the face (alternating hemianalgesia refers to ipsilateral loss of pain and temp from face and contralateral loss of pain and temp from body)
- destruction of the glossopharyngeal and vagus nerve
- destruction for he nucleus ambiguus
- destruction of the solitary nucleus results in ipsilateral loss of visceral sensations and reflexes from the palate and pharynx. Ipsilateral loss of taste from 1.2 of tongue and pharynx
- destruction of spinocerebellum tracts may result in asynergia or hypotonia
- irritation of the vestibular nuclei may result in nystagmus
91
Cerebellopontine angle syndrome
Tumor posterior cranial fossa-acoustic neuroma(compress lateral aspect of pone, cerebellum and medulla)
-destruction of the vestibulocochlear nerve results in deafness and vestibular disturbances
-destruction of the facial nerve results in Bell’s palsy
-alternating hemianalgesia refers to ipsilateral loss of pain and temperature sensations from the face and contralateral loss of pain/temperature sensations fromt he body
(Destructing if descending 5 results in ipsilateral loss of pain/temp sensations from the face...destruction oft he spinal lemniscus results in contralateral hemianalgesia of the body)
-involvement of the cerebral artery peduncle results in some degree of ipsilateral cerebellar ataxia, intention tremor, dysmetria and dysdiadochokinesia
92
Benedikts syndrome
Ipsilateral CN3 palsy and contralateral hemitremor
Diplopiaa
Tremor
Ataxia
Contralateralhemiparesis(CST)
Oklesion of the midbrain tegmentum
- destroy oculomotor nerve results in external strabismus, pupillary dilation and complete ptosis
- destruction of the medial lemniscus results in a contralateral loss of proprioception and 2 point tactile discrimination fromt he body and limbs
- lesionsof the red nucleus, fibers of the superior cerebellar peduncle and midbrain tegmentum rpesent with ipsilateral oculomotor palsy and contralateral motor dysfunction such as tremor ataxia or choreiform movements. Also spacicity
93
Parinaud syndrome
Lesion of superior colliculus which contains a center for controlling upward gaze
-paralysis of upward gaze
Due to a pineal tumor or varix of the great vein of Galen
Also destroy the posterior commissure and concomitant loss of the consensual light reflex
94
Thalamic syndrome(dejerine-Roussy syndrome)
Okie to thrombosis of the posterior choriodal or thalamogeniculate branches of the posterior cerebral arteries
- state of constant spontaneous pain without appropriate external stimulus; diffuse
- modification of emotional control
- patient exhibits extreme mood swings from laughter to sobbing within short time
- may involve contralateral hemihypalgesia (crawling sensation) hemiparesis, homonymous hemianopia, or auditory deficits
95
Lesion MLF (medial longitudinal fasculus)
Converts vestibular influences to the cranial nerves 3, 4, 6 and also has fibers or oculomotor system
Lesion-internuclear ophthalmoplegia
- abnormal response to horizontal gaze in the direction opposite the side of the lesion
- impaired of loss of adduction of the ipsilateral eye and a nystagmus of the abducting eye
96
Lesion paramedian pontine reticular formation
Critical center for horizontal gaze, which is an enhancement of the RF immediately adjacent to abducens nucleus. It is the staging and coordinating area for the oculomotor system. Sends fibers to the abducens nucleus of same side for influencing ipsilateral lateral rectus. Also projects through the contralateral MLF to the contralateral oculomotor nucleus that innervated the medial rectus
Includes lateral gaze center-
Unilateral lesion-paresis or paralysis of horizontal gaze toward the same side of the lesion and a gaze preference away fromt he side of the lesion. (Due o destruction of fibers from it to the ipsilateral abducens nucleus and contralateral oculomotor nucleus
Fibers from the vestibular nuclei and the adjacent paramedian pontine reticular formation decussate int he lower pons and ascend to the oculomotor nucleus in the midbrain .
Lesion symptoms left
Horizontal gaze to right is normal
Horizontal gaze to left showed that the right eye did not adductor and the left eye showed a lateral nystagmus
Both eyes could adductor during convergence
The vestibular nerve has direct connection to it
97
Parkinson’s disease neuroanatomical basis
Subcortical degeneration of substantia nigra, globus pallidus, upper brainstem nuclei, an
Nigrostriatal fibers are dopaminergic fibers that originate in the pars compacta of the substantia nigra and terminate in the caudate and putamen (striatum) the neurons int his area of the substantia nigra are destroyed in parkinsons)
Absence of descending tracts and neuronal pools(they convey either facilitatory or inhibitory influences upon lower motor neurons)
Most descending motor neurons terminate in lower motor neuron pools.
Neurons in pars compacta are destroyed in parkinsons.
Nigrostriatal fibers (dopaminergic fibers)
98
Huntintinton chorea neuroanatomical basis
Nigro-striatal fibers are dopaminergic fibers that originate in the pars compacta of the substantia nigra and terminate int he caudate and putamen (striatum) the neurons in this area of the substantia nigra are destroyed in parkinsons
Destruction of the inhibitory GABAnergic fibers in the striatonigral fibers are involved in huntingtons
Chorea is an AD motor disorder on chromosome 4
Normally the gene called Huntington has CAG repeats MORE
SUDEN IRREGULAR AND INVLUNTARY MOVEMENTS
```
Striatonigral fibers (GABAnergic fibers)
Destroy the inhibitory, GABAnergic fibers on the SN fibers)
```
99
Hemibalism neuroanatomical basis
Parkinsons
Issue with descending tracts
Unilateral lesion in subthalamus (connected to globus pallidus)-regulated output of basal ganglia
Unilateral lesion in subthalamus results in contralateral movement dysfunction characterized by wild movements, flailing or both upper and lower extremities. May be due to the reduction or loss of inhibition of the globus pallidus by the subthalamus.
100
Athetosis neuroanatomical basis
Slow involuntary convoluted writhing movements of fingers, hands, toes, and feet
From cerebral palsy,
Huntingtonss
101
Korsakoff syndrome (wernicke’s encephalopathy)
Due to bilateral destruction of the mammillary bodies and the dorsomedial thalamic nucleus.
Sequalea of long term alcohol abuse and chronic thiamine defiency
Clinical-impairment of recent memory due to defective encoding at the time of original learning
Memory retreival int act
CONFABULATION to fill gaps in story
OR PITUITARY TUMOR (get bitemporal hemianopsia)
102
Uncal herniation/tentorial herniation
Rapid bleeding expands the epidural space, pressing upon the adjacent cerebral hemisphere and herniating the cerebrum under the falx cerebri (falx herniation)
And/or through the tentorial notch (tentorial or uncal hernation)
Herniation of the uncus through the incisors compresses and displaces the midbrain. Bilateral compression of the midbrain reticular formation results in a progressive decrease in the level of consciousness
103
Cerebral cortex lesions
Ok
104
Receptive aphasia
From fluent paragrammatical aphasia from wernickes
Wernickes aphasie-can Speak fluently but that weird speech pattern
Speech patterns demonstrate numerous word substitutions, neologisms (new word creation), and a circumlocution of language that belies an underlying fundamental comprehension deficit .
Get from damage to wernickes are 22...assembly for language CANT COMPREHEND THE SPOKEN OR WRITTEN WORD
105
Gerstmann syndromes
Due to lesion of dominant parietal lobe
Characterized by finger agnosia, right-left disorientation, dysgraphia and dyscalculia
*superior parietal lobule-lesion may cause failure to recognize the body scheme on the opposite side
FINGER AGNOSIA
106
Agnosias
From lesion in superior and inferior parietal lobe
Lesion of parietal lobe may disturb our recognition of our own body parts (denial of body scheme) our ability to discrimate objects (agnosia) or our ability to perform certain complex learned motor activities
Auditory agnosia-lesion of auditory association cortec
107
Frontal lobe syndrome
The prefrontal lobe is functionally an extension of the Limbic lobe. It is involved int he regulation of depth of our feelings, the affective component of visceral and comatosensory sensations, motivation and personality
Prefrontal tumors, infarcts, or lobotomies may cause patient to be easily distracted, unable to plan, tactless, extroverted, without emotional tensions, or released from inhibitions. No change in intelligence
Characterized by apathy, occasional euphoria, abruptly irritability and socially inappropriate behavior
108
Can’t comprehend spoken words
Auditory agnosia
109
Associative visual agnosia
Infarction of left occipital lobe and posterior corpus callosum secondary to occlusion fo the posterior cerebral artery may disconnect language from the visual cortex
110
Inability to demonstrate how to produce a voluntary cough
Agnosia
111
Lesion of dominant hemisphere resulting in apraxia is frequently associated with what
Agnosia
112
Visual agnosia
Can’t visually recognize objects or pictures
113
How get associative visual agnosia
Infarction of left occipital lobe and posterior corpus callosum secondary to occlusion of the posterior cerebral artery
114
Lesion of the middle two thirds of cerebral peduncle
CST and Corticobulbar biers
Contralateral hemiplegia
Contralateral supranuclear facial palsy
115
Red nucleus
Part of RF
Descending pathway for extrapyramidal systems
Lesions
Spacisity seen with UMN
116
Lesions of RN
Intention and or resting tremors bc dentatorubral and dentate-Rubio-thalamic fibers fromt he superior cerebellar peduncle course through the RN
117
Lesion of genu of internal capsule
Conveys Corticobulbar fibers
| Contralateral supranuclear facial palsy and some other cranial nerve somatic motor deficits
118
Obstruction of cerebral aqueduct
Internal hydrocephalus of the lateral third ventricle
119
acoustic neuroma
Common tumor of posterior cranial fossa in adults
| CPA
120
Vertebral arteries join to form what
Basilar artery at level of medulla
121
Chiari malformations
Check upper cervical cord for a syrinx
122
Tonsillar herniation
Mas herniate the cerebellum superiorly, inferiorly or both
123
LMS
Medulla infarct
| Dysphagia, dysphagia, and/or alternating hemianalgesia
124
See trigeminal and vestibulocochlear nerves
Ok
125
Lateral medullary syndrome
PICA problem from medulla damage
| Dysphagia, dysphagia and/or alternating hemianalgesia
126
What supplies cerebellum
PICA
127
Why may PICA branches be displaced
Space occupying lesion in PCF
May herniate cerebellum too (tonsil)
128
What level do we see tonsil
Metencephalon
129
Michele eyes mesencephalon
Red nucleus
130
Mickeys dot under chin
CA
131
CPA/cerebellopontine angle syndrome
Mass of acoustic neurons of vestibulocochlear nerve
132
Obstruction CA
Hydrocephalus third and lateral ventricles
133
What in in the genu
Corticobulbar and corticoretuclar tract
134
Lesion genu
Supranuclear facial palsy and CN somatic motor deficits
135
Red nucleus
Part of reticular formation and is part of major descending pathway for the extrapyramidal system (corti our real-spinal path)
136
Lesion red nucleus
Spasticity seen with UMN lesions
| Resting tremor-damage dentatorubral
137
Dentatorubral fibers
From superior cerebellar peduncle course through the RN
138
What level is middle peduncle on
Mesencephalon
139
What is in cerebral peduncle
CSST
140
Damage to CST at cerebral peduncle along with Corticobulbar fibers
Contralateral hemiplegia
| Also maybe contralateral supranuclear facial palsy
141
What does insular cortex do
Visceral sensation and pain
142
Subthalamus nucleu
Subthalmic nucleus
Red nucleus
Substantia nigra
143
Amygdaloid to hypothalamus
Stria terminalis
144
Mamilllothalmic
Hypothalamus to thalamus
145
__ lobe lesion may cause olfactory hallucinations
Temporal
146
Injury to optic nerve
Can be from demyelination
MS
Visual acuity
Visual field defects
147
Damage oculomotor
Ipslateral oculomotor palsy
Dilation of pupil and slowed pupillary constriction in response to light
Can’t move eye normally
Also supplies sphincter pupillary and upper eyelid muscle (levator palpebrae)
Strabismus and diplopia
148
Trochlear nerve damage
Diplopia from superior oblique paralysis
| Down and out
149
Branches of trigeminal
V1 occipital
V2 maxillary
V3 mandibular (also muscles of mastication)
150
Bell’s palsy
Paralysis of facial muscles
151
What glands does facial nerve control
Lacrimal and salivary
152
Sign of CN7 lesion
Bell’s palsy
Loss of taste anterior two thirds tongue
Altered lacrimal salivary secretion
153
Lesion CNVIII
Tinnitus, vertigo, hearing deficits
154
Conductive deafness
External or middle ear
155
Sensorineural deaf
Disease in cochlea or central auditory pathway
156
Glossopharyngeal lesion
Absence of taste on posterior third of tongue, gag reflex absent on the side of lesion
Change in swallowing
157
Glossopharyngeal neuralgia
Sudden onset of pain initiated by swallowing protruding the tongue, talking or touching the palatine tonsil
158
Vagus nerve injury
Pharyngeal branches-dysphagia
Superior laryngeal nerve-anesthesia of the superior aspect of the larynx and paralysis of the Cricothyroidotomy muscle
Recurrent-dysphonia or aphonia
159
Lesion nucleus ambiguus
Nasal speech, dysphagia, dysphagia, and deviation of the uvula toward the contralateral side
160
Lesion facial motor nucleus
In brainstem
| Atrophy of muscles of facial expression
161
The muscles of the face receive input from
Contralateral input from opposite motor cortex
162
Direct activation path
UMN to pyramida tract
163
Indirect path
Extrapyramidal tract which has contact with LMN
164
Control circuits
Basal ganglia, cerebellum, have NO direct contact with LMN
165
UMN
From motor cortex and synapse onto cranial nerve nuclei in contralateral brainstem (corticobulbar) or onto cells in the contralateral spinal cord (corticospinal tract)
166
LMN
Originate in cranial nerve nucleu(cranial nerve) or spinal cord(spinal nerves) they synapse onto muscles
167
What is the junction between LMN and muscle
Motor end plate
168
CST
Main path for all voluntary msucles
UMN
Cross at pyramids
169
Prefrontal cortex UMN
UMN initiate movement
170
Frontal lobe UMN
Do not initiate impulse
| Suppress and inhibit LMN
171
If lose inhibitory UMN
Spasticity
172
CBT
UMN from motor cortex lower third
| Crosses
173
Damage UMN
Spasticity and cant initiate skilled movement
| Reflexes exaggerated
174
LMN damage
Flaccidity decreased muscle tone
175
Bilateral UMN lesion
Spastic dysarthria
Pseudobulbar dysarrhythmia
Strained phonation imprecise articulation
176
Unilateral UMN lesion
Flaccid dysarthria
| Unilateral lower facial weakness vocal prob
