1
Q
Babinski sign
A
- Upturning toes indicates pathological upper motor neuron lesion
- Corticospinal tract
2
Q
Corticospinal tract
A
- Voluntary mvmt of body
- 80% Cross over at medulla
- Originate in cerebral cortex
- Form pyramids of medulla
- Upper motor neurons
- Synapse with interneurons
3
Q
Deep tendon reflexes
A
- Stretch reflex, direct response from spinal cord
-Hyporeflexia- Lower motor neuron
Hyperreflexia- Upper motor neuron, pyramidal tract
4
Q
Flaccid paresis
A
- Lower motor neuron
- Weakness, hypotonia, hyporeflexia
- GBS, encephalopathy, botulism
- Inability to contract muscles
5
Q
Hemiparesis
A
- Injury above medulla cause contralateral hemiparesis
- Injury below medulla cause ipsilateral hemiparesis
6
Q
Hyperreflexia
A
- Upper motor neuron involvement
- Can be DTRs or superficial
7
Q
Superficial reflex
A
- Sensory signal must ascend to brain
- Interruption of pathway between brain and spinal cord
8
Q
Hypertonia
A
- Upper motor lesion
- Anterior horn of spinal cord
- Reticulospinal tract
9
Q
Hyporeflexia
A
- Lower motor neuron issue
10
Q
Hypotonia
A
- Diminished resistance to passive movement
- Lower motor neuron disease
11
Q
Internal capsule
A
- Ascending and descending motor neurons
- Corticospinal tract travels through
- Going to and coming from cerebral cortex
- Primary motor cotrex- hemiparesis and hemiplegia
12
Q
Lateral corticospinal tract
A
- Fine mvmt of ipsilateral limbs
- Largest part of corticospinal tract
- Descending motor neuron
- Decussates in pyramid of medulla
13
Q
Pyramidal tract
A
- Originate in cerebral cortex
- Carry motor fibers to brainstem, spinal cord
- Voluntary control of musculature
14
Q
Extrapyramidal tract
A
- Originate in brainstem
- Motor fibers to spinal cord
- Involuntary control of musculature
- Tone, balance, posture and locomotion
15
Q
Primary motor cortex
A
- Organized somatotopically
- Dorsal potion of frontal lobe
- Excites lower motor neuron, inhibits reflexes, tone
- Betz cells
- Anterior to central sulcus
- Activates contralateral side of body
- Posterior limb of internal capsule
- Cross over at medulla
16
Q
Premotor cortex
A
- Frontal lobe, anterior to primary motor cortex
- Timed individual mvmts via direct and indirect stimulation
- Excites groups of neurons
- Spatial and sensory guidance of tasks
- Visually cued conditional tasks
- Projects to spinal cord
- Trunk muscles
17
Q
Reticular formation
A
- Brainstem
- Interconnected nuclei, motor integration
- Behavioral arousal and consciousness
- CV control
- Pain modulation
- Habituation
- Sleep and consciousness
- Raphe, red and parvocellular nuclei
18
Q
Ventral corticospinal tract
A
- Descending
- Cerebral cortex to spinal cord
- Ends in mid thoracic region
- Cross at anterior white commissure
- Voluntary motor impulses to precentral gyrus
19
Q
Ventral horn of spinal cord
A
- Motor neurons of axial muscles
- Corticospinal tract runs through
- Intact sensation but weakness with lesion
20
Q
Vestibular nuclei
A
- Medulla
- Input from CN VIII
- Lateral and medial nucleus to cerebellum
- Vestibulospinal tract- coordinate head and trunk movements
21
Q
Vestibulospinal tract
A
- Extrapyramidal system
- Motor commands
- Alter muscle tone, extend and change position of limbs and head
- Maintain posture and balance
- Medial pathway, anterior horn cells
- Funiculus
- Righting reflex
22
Q
Lateral tracts
A
Precise movement of distal limbs
23
Q
Medial tracts
A
Gross movement of proximal limbs and trunk
24
Q
Muscle tone
A
- Continuous, passive contraction of muscles
- Hypertonia = UMN
- Hypotonia = LMN
25
Neuromuscular junction
- Very large synapse, contact points
| - LMN to skeletal musc
26
Nicotinic acetylcholine receptor blockers
- Paralysis of muscle, can't sense ach
- Inhibit effect of acetylcholine
- Immobilization of pts
27
Acetylcholine agonists
- Nicotine is mild agonist
- Activation of cholinergic system- BP, addiction
- Stimulates muscle and doesn't allow reexcition- exhaustion of muscle
28
Acetylcholinesterase blockers
- Build up of acetylcholinesterase at neuromusc jxn
- Tx myasthenia gravis
- Indirectly provided cholinergic action
- Prolongation of muscle activity
29
Stretch reflex arc
- Activated by DTRs
- Direct activation of LMN
- Stretch -> afferent signal -> spinal cord -> efferent reflex -> activate musc, inhibit antagonist
- Protective measure
- Responsible for muscle tone
30
Lateral funiculus motor systems
- Contralateral corticospinal and spinothalamic tracts
- Ventral horn
- Activate lateral musculature (forearms)
- Internal capsule
- Inhibition from ventral horn
31
Primary motor cortex
- Precentral sulcus of central lobe
- Analogus to primary somatosensory cortex
- Fine motor control areas larger
32
Corticospinal tract
- Limbs, head and trunk
33
Corticobulbar tract
Face, neck, throat
34
Lesion of lateral corticospinal tract
- Ipsilateral deficit, weakness
- Loss of fine motor movement in distal extremities
- Hypertonia/ spasticity and clonus
- Exaggerated babinski sign
35
Unilateral destruction at dorsal column- C4
Ipsilateral proprioception loss
36
Proprioception sensation
- DCML
| - Decussates at caudal medulla
37
Unilateral destruction at dorsal root ganglion- C4
- Ipsilateral proprioceptive sensation loss
38
Unilateral destruction at anterolateral system- C4
- Unaffected
39
Unilateral destruction at lateral primary sensory cortex
Contralateral proprioception
| - Loss of face
40
Unilateral destruction at medical somatosensory cortex
Contralateral proprioception
| - Loss of limbs
41
Reticular activating system
- Within reticular formation
- Interconnected nuclei
- Regulates activity in cerebral cortex
- Auditory and temperature activation
- Avoidance of pain, smells
42
Paresthesia
- Odd, unnatural sensation
- Peripheral neuropathy,
- Damage to relay nucleus, nerve or primary cortex
43
Dysthesias
Unpleasant or painful sensations produced by stimulus
