chapter 15 Flashcards
1
Q
- originate in the brain, terminate in the spinal cord
- send axons down SC tracts
A
upper motor neurons
2
Q
originate in the spinal cord and terminate in skeletal muscle
A
lower motor neurons
3
Q
loss of movement
A
paralysis
4
Q
paresis
A
weakness
5
Q
stroke or paralysis
A
plegia
6
Q
mono
A
one limb
7
Q
hemi
A
both limbs on one side
8
Q
di- or para-
A
relating to both upper or lower limbs
9
Q
quadri- or tetra-
A
relating to all four limbs
10
Q
less than normal muscle tone
A
hypotonia
11
Q
absent muscle tone
A
flaccidity
12
Q
descriptors indicating higher than normal muscle tone
A
- hypertonia
- rigidity
- spasticity
- tetany
13
Q
- impulses from pyramidal neurons in precentral gyrus pass through corticospinal tracts
- descend w/o synapsing and decussate at the medullary pyramids
- axons synapse w/ interneurons or ventral horn motor neurons
- regulates fast and fine (skilled) movements
A
direct (pyramidal) pathway
14
Q
cross sectioning of the spinal cord at any level, results in total motorand sensory loss in regions inferior to the cut
A
transection
15
Q
transection between T1 and L1 results in
A
paraplegia
16
Q
transection in the cervical region results in
A
quadriplegia
can result in death if affecting C3-C5 (phrenic nerve that keeps the diaphragm alive)
17
Q
transient period of functional loss caudal to lesion
A
spinal shock
18
Q
a neurological condition that causes involuntary and rhythmic muscle contractions and relaxations
A
clonus
19
Q
parasthesias
A
sensory loss
20
Q
motor function loss
A
paralysis
spastic or flaccid
21
Q
- damage to UMNs of primary motor cortex
- spinal neurons remain intact
- muscles are stimulated by reflex activity–no voluntary control
- muscles often shorten permanently
A
spastic paralysis
22
Q
- severe damage to ventral root or ventral horn cells
- impulses do not reach muscles
- no involuntary or voluntary control of muscles
- muscles atrophy
A
flaccid paralysis
23
Q
- smoothens and coordinates skillful movements
- influences voluntary and automatic aspects of movement
- does NOT initiate activity
- integrates sensory information concerning position of body parts
- coordinates skeletal muscle activity
- maintains posture
A
cerebellum
24
Q
- often due to congenital defects, vascular accidents, and a growing tumor
- results in ataxia, nystagmus, tremor, dysphagia, and dysarithria
A
cerebellar disorders
25
* neurological sign that refers to a lack of muscle coordination, which can cause clumsy movements:
* abnormal eye movements, like nystagmus; changes in speech, like scanning speech; difficulty walking; lack of balance; slurred speech; trouble swallowing
ataxia
26
* a condition that causes involuntary, rhythmic eye movements
* movements can be side to side, up and down, or circular
* can affect one or both eyes, and the movements can be continuous or intermittent
nystagmus
27
* a speech disorder that makes it difficult to speak clearly due to issues with the muscles, nerves, or brain that control speech
* makes it difficult to form and pronounce words
dysarithria
28
a neurological procedure that damages the globus pallidus, part of the brain's basal ganglia
pallidectomy
29
* often leads to involuntary movement, changes in muscle tone, and disturbances in body posture
* features: tremors, hypokinetic movements, and hyperkinetic movements
basal ganglia disorders
30
types of hyperkinetic movement
* chorea
* athetosis
* ballismus
* dystonia
31
jerky movements
chorea
32
continuous twisting movements
athetosis
33
violent flinging movements
ballismus
34
rigidity
dystonia
35
**TREATMENTS**
* cannot use dopamine, as it cannot cross the blood brain barrier
* have to use Levodopa (L-Dopa), as it can cross BBB
* surgical procedures such as a pallidectomy
treatments of parkinson's disease
36
**SIGNS AND SYMPTOMS:**
* develop slowly usually and start on one side and then proceed to both sides of the body
* *motor:* tremor (pill rolling at rest), bradykinesia, cogwheel rigidity, difficulty starting and stopping movements, balance and coordination problems, may freeze, lost blinking reflex, forward leaning
* *autonomic:* excessive sweating, salivation, lacrimation, orthostatic hypotension, depression, and dementia in 15-20% of pts
(signs and symptoms of) Parkinson's Disease
37
* chronic disorder of basal ganglia funciton characterized by slowness of voluntary movements, rigidity, and tremor
* degeneration of substantia nigra --> overactive BG --> sends abnormal stimuli to cortex --> motor problems
Parkinson's disease
38
* damages both UMNs (weakness, lack of motor control esp. over spinal reflexes; stiffness and spasticity) and LMNs (causing irritation due to decreased neuronal firing --> weakness, denervation atrophy, and hyporeflexia
* results in loss of myelinated fibers in the corticospinal tracts
* atrophy of precentral gyrus
* affects mostly men between 40-60 y/o
* fatal
* due to degeneration of UMNs in spinal cortex and cell bodies in brainstem and anterior horn cells of the spinal cord
Amyotrophic Lateral Sclerosis (ALS)
## Footnote
aka Lou Gherig's Disease
39
**SIGNS AND SYMPTOMS**
* when LMNS die, denervation occurs due to lateral sclerosis in SC's lateral column, results in muscular atrophy
* generalized muscle weakness
* paresis in localized muscle group (which may manifest as muscle cramps in distal legs)
Amyotrophic Lateral Sclerosis (ALS)
40
**TREATMENT**
* antispasmodic drugs
* respiratory support
(treatments of) ALS
41
* damage to many nerves whether by demyelination or axonal degeneration of peripheral nerves
* longest axons affected first, symptoms begin in distal extremities
* if ANS is involved --> hypotension, impotence, constipation
polyneuropathies
## Footnote
ex: Guillain-Barré Syndrome
42
causes of polyneuropathies
1. immune mechanisms (ex: Guillain-Barré syndrome)
2. toxic agents (arsenic, lead, alcohol)
3. metabolic diseases (diabetes mellitus, uremia)
43
* mostly follows a viral infection (typically either upper RT or GI tract)
**SIGNS AND SYMPTOMS**
* ascending muscle paralysis of the limbs (symmetric flaccidty and paralysis of respiratory muscles)
* parasthesia and numbness
* ANS involvment (postural hypotension, arrhythmias, sweating abnormalities, urinary retention
Guillain-Barré Syndrome
44
**TREATMENT**
* maintain pt airway
* support respiration
* steroids
(treatments of) Guillain-Barré Syndrome
45
damage to one nerve
mononeuropathies
## Footnote
eg: Carpal Tunnel Syndrome
46
one single lower motor neuron and all of the skeletal muscle fibers it is controlling
motor unit
47
responsible for fine, precise movements
small motor units
48
responsible for strength, and force of contraction
large motor units
49
a process that occurs when a nerve fiber is damaged, causing the axon distal to the injury to break dow (axon and myelin sheath), causing astroglial scar tissuse to replace it
Wallerian Degeneration
50
* compression of the median nerve as it passes w/ flexor tendons through canal or tunnel made by carpal bones and transverse carpal ligaments
* due to reduction in size of tunnel or an increase in the volume of tunnel contents
* caused by wrist injury or wrist overuse
carpal tunnel syndrome
51
**TREATMENT**
* splinting
* rest
* surgery
* anti-inflammatory drugs
(treatment of) carpal tunnel syndrome
52
**SIGNS AND SYMPTOMS**
* pain
* parasthesias
* numbness in thumb and fingers
carpal tunnel syndrome
53
potential issues with the motor unit
* NMJ disorders
* muscular atrophy or dystrophy
* LMN lesions or infections
* peripheral nerve injury
54
typical NMJ problems
* decreased ACh release
* decreased ACh effects on the muscle cell
55
a plant derived substance that affects voluntary muscles by blocking the motor end plate, leading to muscle paralysis
curare
56
* a disease in which antibodies made by a person's immune system prevent certain nerve-muscle interactions (autoimmune)
* ACh receptors on muscle cells are destroyed
* causes weak and easily fatigued muscles
myasthenia gravis
57
**SIGNS AND SYMPTOMS**
* difficulty swallowing and chewing
* drooping eyelids
* ventilator needed if respiratory muscles are affected
myasthenia gravis
58
**TREATMENT**
* drugs that increase the release of acetylcholine (ACh)
* removing thymus gland
* immunosuppressant drugs
(treatment of) myasthenia gravis
59
types of peripheral nerve injuries
* demyelination
* axonal degeneration
60
reasons for demyelination
* schwann cell disorder
* damage to myelin sheath
61
reasons for axonal degeneration
* damage to LMN cell bodies in the spinal cord
* damage to axons in the spinal or peripheral nerves
62
* demyelinating disorder of white matter of brain, spinal cord, and optic nerve
* occurs mostly in young and middle aged adults
* females are 2x more at risk than males
* first symptoms arise at 20-40 y/o
* remyelination can occur if demyelinating process can be stopped before oligodendrocytes die
multiple sclerosis
63
demyelination and gliosis
stage 2 multiple sclerosis
64
**SIGNS AND SYMPTOMS**
* vision disturbances
* fatigue and weakness
* bowel and bladder dysfunction
* vertigo
* tinnitis
* facial weakness
multiple sclerosis
65
inflammatory lesions
stage 1 multiple sclerosis
66
**TREATMENT**
* steroids
* immunosuppressive drugs
(treatment of) multiple sclerosis
67
* destruction of ventral horn motor neurons--muscles atrophy
* death may occur from paralysis of respiratory muscles or cardiac arrest
poliomyelitis virus
68
semi-permeable membrane that surround muscle cells, separating the intracellular and extracellular environments
sarcolemma
69
* due to lack of innervation
* if LMN dies or axon destroyed
* muscle cells in motor unit go through temporary, spontaneous contractions
* after a few months, muscle degenerates
* crushed axons in PNS can regenerate when proper conditions are provided
denervation atrophy
70
* 1 in 3,500 births
* females are carriers, disease seen mainly in males
* detection between 2-7 years old
* death in early 20s
* muscle fibers lack dystrophin
* present w/ problems regulating calcium release
duchenne muscular dystrophy
71
role of dystrophin
stabilizes sarcolemma
72
**SIGNS AND SYMPTOMS**
* postural hip muscles affected first
* shoulder muscles next
* frequent falling from 3-4 y/o
* death due to respiratory and cardiac muscle wasting
signs and symptoms of duchenne muscular dystrophy
73
how is duchenne muscular dystrophy diagnosed
* muscle biopsy
* EMG
* gene probes
74
**TREATMENT**
* prednisone
* myoblast transfer therapy
(treatment of) duchenne muscular dystrophy
75
* originates in the motor cortex and provides control of delicate muscle movement
pyramidal motor system
76
* originates in the basal ganglia
* provides background for more crude, supportive movement patterns
extrapyramidal system
77
what can cause the death of LMNs
* loss of spinal reflexes
* flaccid paralysis
* denervation atrophy of muscles
78
an injury to the C7 peripheral nerve results in
hand weakness only
79
a spinal cord injury at T12 or lower results in
flaccid paralysis to body levels below site
80
* disruption of communication between muscle and all neural input from spinal cord reflexes
* causes spontaneous contraction of muscle units
* can be due to infeciton or inflammation of LMN (e.g. due to poliomyelitis virus)
LMN lesions
81
* weakness and loss of voluntary motion
* spinal reflexes remain intact but cannot be modulated by the brain
* increased muscle tone
* hyperflexia
* spasticity
upper motor neuron lesion
82
lesion at or above the level of the pyramids results in...
paralysis on the opposite side
83
**SIGNS AND SYMPTOMS**
* loss of fine, skilled, voluntary lower limb movement
* reduced bowel and bladder function
* reduced sexual function
* hypertonia
L1 UMN lesion (or above)
84
**SIGNS AND SYMPTOMS**
* loss of fine, skilled, voluntary lower limb movements
* reduced bowel and bladder functiion
* reduced sexual function
* hypertonia
* reduced upper limb movement
* LMN reflexes intact, but no more input from higher brain centers
* immediate weakness--later converts to hypertonicity or spasticity and clonus
above C5 UMN lesion
