neuro pt 2 Flashcards
functions of nervous system
detecting, analyzing, and transmitting information
neuroglial
-capable of mitosis
-protect and provide developmental, physiological, and metabolic support fot neurons
sensory neurons
have dendrites on both ends
-connected by long axon with cell body in middle
-carry signals from peripheral to central
Afferent
incoming sensory pathways
motor neurons
control muscle contactions
- have cell body on one end. long acon and dendrites on the other end
-carry signals from central to peripheral
efferent
outgoing motor pathways
ICP
pressure inside skull, include brain(78%), CSF(10%), and blood(12%)
should alwyas be balanced
levels of ICP
normal: 5-15
Moderate 21-30
very severe: 41+
causes of increased ICP
acquired brain injury (non-traumatic)
traumatic brain injury
early s/s of increase ICP
LOC
sluggish pupillary response headache
slurred speech
decrease motor function
projectile vomitting
late s/s of increase ICP
increased confusions
dilated pupils
changes in vitals
abdnormal reflexes
loss of brainstem reflexes
decorticate and decerebrate
cushing’s triad
sign of cerebral swelling
1. change in respirations-irregular and deep
2. a widening pulse pressure
3. bradycardia
concussion
mild form of TBI by impact to head or whiplash
contusion
bruises on specific brain areas from impact to head
coup contrecoup
contusion present at both the site of impact and the exact opposite end of impact
diffuse axonal injury
tearing of brain’s axons
-happens when brain is injured as it shifts and rotates in skull
-causes coma
-may have normal CT
chronic traumatic encephalopathy (CTE)
brain degeneration likely caused by repeated head traumas
-diagnosis made only at autopsy
second impact syndrome
aka repetitive head injury syndrome
-individuals expereince a second head injury before complete recovery from initial injury
TBI: epidural hematoma
arterial bleed
-high pressure bleed, fast bleeding
-most dangerous
-increased ICP
-untreated= death fast!
TBI: subdural hematoma
venous bleed
-low pressure bleed
-increased ICP
Subarachnoid Hemorrahage (not stroke)
small arteries tear during initial injury
-pathologic presence of blood within subarachnoid space
-2nd most common acute brain injury
roles of spinal cord
send motor commands from brain to body
-send sensory info from body to brain
-coordinate reflexes
ascending spinal tract
sends sensory info to brain
descending spinal tract
sends motor info down the cord
complete SCI
all sensory and all motor control are lost below level of inury
incomplete SCI
some motor or sensory function loss below affected area are preserved
paraplegia
paralysis that affects all of part of the trunk, legs, and pelvic organs. may still have movement of upper limbs
tetraplegia/quadiplegia
arms, hands, trunk, legs, and pelvic all affected,
basically neck down, no bueno
brown sequard ISCI
usually caused by puncture or infection
-symptoms: same sided weakness, loss of bladder/bowel control, contralateral sensory loss
-excellent prognosis
central cervical cord syndrome ISCI
-cause: hyperextension of neck, spinal cord gets bruised squashed or compressed
-symptoms: most commone ISCI, impacts upper limbs more than lower, sevre arm weakness
-high chance of walking again
posterior ISCI
cause: SCI trauma, demylinated disorders, external compression
-symptoms: low sensation of vibration/fine touch, loss of proprioception, loss of balance/coordiantion, power perserved
-good prognosis, walk again but very unsteady/fall risk
anterior ISCI
cause: severe blood loss, anterior 2/3 of spinal cord
-symptoms: motor paralysis below level of lesion, loss of pain sensation below injury, preserved touch and proprioception
-poor prognosis 10-20% chance of motor recovery
Spinal shocks
-inital shock/ “temporary”
-T7 or below
-complete loss of reflex function
-transient drop in bp and poor venous circulation
-loss of thermal control
neurogenic shock
-T6 or above
-sudden loss of sympathetic nervous system that maintains normal vascular tone
-blood volume is displaced causing hypotension and bradycardia
-right after SCI, can also happen well after
Autonomic nervous system dysfunction
-aka autonomic dysreflexia or neurogenic shock
-most common SCI at or below T6
-SNS massively overacts to a noxious stimulus
-PNS not effective at regulating below SCI
-vasodilation above injury
-vasoconstriction below injury
PNS and SNS out of control
disorders of upper motor neurons
ALS
-TBI
-SCI
-MS
-CVAs
-huntingtons disease
disorders of lower motor neurons
poliomyelitis
Multiple sclerosis
progessive diseas of the brain and spinal cord
-destruction of mylein sheath on CNS
-causes: largely unknown, auto-immune, genetic suseptibility
-pathogenesis: T cells attack myelin sheath, demyelination, damages action potential between axon on neurons
ALS
neurodegenerative disorder affects motor system and presents with progressive muscle weakness
-aka Lou Ghrigs disease
-pt. survives about 2-5 yrsafter disease onset
symptoms of ALS
impaire fine motor control
-change in vocal pitch
-slurred speech
-dysphagia
-severe weakness
-muscle cramps
-uncontrolled laughter/crying
-muscle atrophy
-problems speaking
-impaired breathing
myasthenia gravis
-mostly affects women in 20-30s and men 50-60s
-drooping eyelids
-weakness of eye muscles and facial muscles
-double vision
-excessive muscle fatigue after activities
-impaire speech
-weakeness of upper and lowe extremities
generalized myasthenia gravis
chronic type 2 hypersenstivity
-B-cells make antibodies that bind to ACh receptors
-blocks transmission og ACh to post-synaptic membrane
-messages from CNS to contract muscles fail
