Chapter 23 - Nervous System Flashcards
1
Q
meninges layers
A
dura mater: outer
arachnoid mater: AKA subarachnoid space; CSF here
pia mater: inner most; delicate as fuck
2
Q
function of cerebrospinal fluid
A
cushion and protect brain
3
Q
what structure makes cerebrospinal fluid
A
choroid plexus
4
Q
components of CSF
A
clear
small amount of protein
glucose
5
Q
two divisions of the nervous system
A
Central and peripheral
6
Q
components of the brain
A
cerebrum
cerebellum
brain stem
7
Q
where are vascular interconnections located on the brain
A
base of the brain
8
Q
what can only move across the blood brain barrier
A
small, fat soluble molecules
9
Q
what cells make myelin?
A
oligodendrocytes
10
Q
what cells make cerebral spinal fluid
A
ependymal cells
11
Q
what cells wrap around axons?
A
schwan cells
12
Q
EEG
A
electroencephalogram - used to measure electrical activity of the brain
13
Q
angiography
A
procedure that looks for abnormal distribution of blood vessels in the region of a lesion
14
Q
when do genetic/developmental diseases typically start their deleterious forces?
A
within the first half of gestation
15
Q
what is a neural tube defect?
A
incomplete development of brain, spinal cord, and/or meninges
16
Q
what are the two types of neural tube defects?
A
spina bifida
anencephaly = without brain
17
Q
many neural tube defects are caused by a deficiency in?
A
folate/folic acid
18
Q
what tests do you use to diagnose neural tube defects?
A
ultrasound or amniocentesis
19
Q
what is hydrocephalus?
A
large head from an accumulation of cerebral spinal fluid
20
Q
causes of hydrocephalus (3)
A
-obstruction in the flow of CSF
-overproduction of CSF
-inability of arachnoid granulations to restore CSF back into circulation
21
Q
hydrocephalus in children vs. adults
A
children - enlargement of skull
adults - swelling inward, pushing on brain
22
Q
signs and symptoms of hydrocephalus
A
-dilated pupils
-increased BP
-headache
-nausea/vomiting
-seizures
-drowsiness/altered consciousness
23
Q
treatment for hydrocephalus
A
-eliminate the cause
-reduce the pressure
-intracranial shunts
-osmotic agents
-craniotomy
-steroid therapy
-medically induced coma
-hypothermia to slow brain metabolism
24
Q
what is meningitis
A
inflammation of the meninges
25
what is the most common cause of meningitis?
bacteria - gains access to brain and spinal cord via the blood
26
major signs and symptoms of meningitis?
-neck rigidity
-fever
-headache
27
diagnosis of meningitis
spinal tap to collect CSF
28
treatment of meningitis
-antibiotics
-steroids to reduce inflammation
29
what is encephalitis?
diffuse inflammation of the brain
30
what is encephalitis caused by?
viral infections; many are mosquito-borne
31
symptoms of encephalitis
-irritability
-drowsiness
-headache
32
how to diagnose encephalitis
depends on culture and type of viral agent by serologic testing
33
treatment for encephalitis
no specific treatment; you either die, recover fully, or partially recover with neurologic defecit
34
what is poliomyelitis
virus that destroys nerve cells in the spinal cord (causing paralysis)
35
what causes polio?
poliovirus
36
how is polio transmitted?
fecal-oral contamination
37
outcomes of polio
most asymptomatic (95%), less than 1% paralytic
38
what is a cerebrovascular accident?
aka: stroke
-sudden neurologic deficit caused by vascular occlusion; leads to infarcts
39
what is the fourth leading cause of death in the US?
stroke or CVA
40
what is the most common cause of CVA/stroke?
cerebral thrombosis
41
what is a cerebral embolus?
blockage of cerebral artery by a fragment of blood clot from arteriosclerotic plaque; less frequently
42
what is a cerebral hemorrhage?
excess bleeding usually from a ruptured cerebral aneurysm; MOST SERIOUS TYPE OF STROKE
43
how many patients die of CVAs caused by brain hemorrhage?
up to half of patients because of accumulation of blood; rapidly elevates intracranial pressure
44
signs and symptoms of CVAs
-impaired speech or consciousness
-hemiparesis
-poor coordination
-confusion
45
outcomes of CVAs
-1/3 die within 2 weeks
-1/3 recover w/ deficit
-1/3 recover with no deficit (dissolved embolus)
46
Traumatic brain injury (TBI)
brain collides with the inside of skull; causes bleeding, bruising, and tearing of nerve fibers
47
coup vs. contrecoup
coup = direct; primary impact
contrecoup = indirect; secondary impact
48
results of CNS trauma/tbi
-fracture
-injury within the brain (intraparenchymal)
-vascular injury
49
what is the most common head injury?
concussion
50
definition of cerebral concussion
immediate loss of consciousness for seconds to minutes
51
etiology of a concussion
-blunt force impact to head
-brain strikes and rebounds from skull
-disruption of normal brain activity (loss of consciousness)
52
epidural hemorrhage of brain
-hemorrhage above the dura mater; usually in meninges artery
-forms quickly; fatal within 24 hours
53
subdural hemorrhage of brain
-hemorrhage under dura mater
-slow, venous bleeding; 4-6 weeks
54
subarachnoid hemorrhage of brain
-hemorrhage between arachnoid and pia mater where CSF is
-arterial bleeding
-typically from circle of Willis
55
intracerebral hemorrhage of brain
-hemorrhage within brain tissue
56
treatment of TBIs; mild and severe
mild = bed rest and analgesic meds (painkillers)
severe =
-diuretics
-antiseizure and coma-inducing meds
-surgery to remove clots, repair fractures
-craniotomy
57
what is a seizure?
alteration of brain function caused by disorderly discharge of cerebral neurons (abnormal brain electrical activity)
58
epilepsy
2 or more unprovoked seizures occur more than 24 hours apart
59
causes of provoked seizures
-fever
-electrolyte imbalances
-hypoglycemia
-hypoxia
-arrhythmias
-CNS infection/damage
-head trauma
60
causes of unprovoked seizures
idiopathic; strong genetic basis
61
partial seizure
focal; only one small area of the brain
62
simple seizure
w/o loss of consciousness
63
complex seizure
loss of consciousness
64
generalized seizure
occurs in both hemispheres of brain, can be convulsive or nonconvulsive
65
absence (petit mal) seizure
brief loss of consciousness
66
atonic seizure
loss of muscle tone
67
myoclonic seizure
muscles contract
68
clonic seizure
repetitive jerking movements
69
tonic
muscle stiffness, rigidity
70
grand mal seizure
muscles contraction; loss of consciousness
71
how to diagnose a seizure
-EEG
-MRI/CT
72
treatment of seizures
-avoid precipitant
-anti-convulsants (reduce electrical activity)
-surgery (remove seizure focus)
73
degeneration of what is Alzheimer's Disease
cortical neurons
74
degeneration of x = MS
myelin
75
degeneration of x = parkinson's and huntington's disease
basal ganglia
76
general etiology of neurodegenerative disorders
-genetic predisposition
-environmental toxins
-oxidative stress
-aging
77
multiple sclerosis definition
damaged myelin sheaths; disease of oligodendrocytes
78
what is the most common neurologic disability in young adults?
multiple sclerosis
-chronic, progressive, irreversible
79
what percentage of MS patients are unable to walk without assistance 15 years after onset?
50%
80
etiology of MS
autoimmune disease that attacks myelin
-genetic susceptibility
-environmental trigger
81
is MS associated with peripheral neurons?
no - central
82
symptoms of MS
-visual impairment
-urination
-motor weakness
-numbness
-fatigue
-mood swings
83
treatment of MS
-relieve symptoms
-drug therapy to slow progression
84
prognosis for MS
-no cure
-usually die from infections, not disease itself
85
what is dementia
irreversible deterioration of cerebral cortex
86
is dementia age related?
no - not normal part of aging
87
losses in dementia
-orientation
-memory
-language
-judgment
-decision making
88
what is the most common form of dementia?
alzheimer's disease
89
what part of the brain is affected with alzheimer's disease
cerebral cortex; frontal and temporal lobes
90
etiology of alzheimer's
unknown; but it is irreversible, progressive, and chronic
91
what two features are associated with alzheimer's disease?
-amyloid plaques
-neurofibrillary tangles
=decreased acetylcholine production
92
risk factors for alzheimer's disease
-age
-chronic hypertension
-head injury (3x more likely to develop Alzheimers)
93
mult-infarct vascular dementia
cumulative brain damage from small strokes; 2nd most common type of dementia
94
what cells are affected with parkinson's disease
basal ganglia (beneath the cortex)
95
cause of parkinson's disease
unknown; but decreased dopaminergic neurons (less dopamine)
96
manifestations of parkinson's
-disturbances of movement
-rigidity
-bradykinesia
-pill rolling tremor
-abnormal gout
-postural instability
97
how do you treat parkinson's disease
drugs to increase dopamine; no cure
98
what cells are affected in huntington's disease
basal ganglia (beneath the cortex)
99
what is huntington's disease characterized by?
chorea = involuntary, gyrating movements, progressive dementia
100
what type of genetic neurodegenerative disease is Huntington's disease?
autosomal dominant; age-associated
101
neoplasia of brain - metastatic tumors vs. primary
metastatic tumors are more common than primary tumors
102
glioma
poorest prognosis because located deep in the brain; doesn't respond well to treatment
103
astrocytoma
cancer of the astrocyte
104
oligodendroglioma
cancer of the oligodendrocytes
105
lymphoma
cancer of T or B cells
106
meningioma
cancer of the meninges
107
is meningioma benign or malignant
benign in biological sense; depends where it is and what it presses on
108
most common signs and symptoms of brain neoplasms
-increased pressure
-edema
-generalized headache, vomiting, blurred vision, seizures
109
amyotrophic lateral sclerosis (ALS)
death of alpha motor neurons; affects upper and lower motor neurons - damaged nerve fibers
110
ALS only affects what type of muscle
skeletal
111
is ALS age-associated?
yes
112
is ALS a peripheral or central nervous system disease?
peripheral
113
cause of ALS
unknown
114
treatment of ALS
no treatment or cure
115
manifestations of ALS
-muscle atrophy
-paralysis of muscles
-respiratory problems
116
two forms of ALS
sporadic - 90%
familial - 10%
117
What is guillain-barre syndrome?
autoimmune disease that attacks peripheral nerves leading to inflammation and progressive weakness from extremities toward trunk
118
guillain-barre syndrome is polyneuropathic which means:
it affects many nerves in different parts of the body
119
symptoms of guillain-barre syndrome
weakness
tingling
120
can guillain-barre syndrome be life-threatening?
yes - breathing issues
121
bell palsy
unilateral facial nerve paralysis
121
what is guillan-barre syndrome usually preceded by?
viral or bacterial "flu-like" infection
122
cause of bell palsy
unknown
123
symptoms of bell palsy
-inability to control facial muscles
-twitching, weakness
-drooping eyelid
-drooling
124
prognosis of bell palsy
good; symptoms decrease within 2 weeks and complete recovery within 3-6 months *temporary
125
definition of headache
diffuse pain occurring in any portion of the head
126
primary headache
tension, migraine, cluster headaches
127
secondary headache
underlying structural problems
128
there are no pain receptors in the brain, so where does the pain come from
result of vasodilation -- treat with vasoconstrictors
129
migraine headache
-recurrent, intense, throbbing headache
130
do migraines affect women or men more?
women - estrogen
131
aura (migraines)
visual disturbance before the pain of migraine
132
legally brain dead
two EEGs taken 24 hours apart show complete absence of electrical activity in the brain
133
loss of motor neurons is called
neurogenic paralysis
