Exam 5 Flashcards
(94 cards)
1
Q
Axons
A
conduct impulses AWAY from cell body
2
Q
Dendrites
A
conduct impulses TOWARD cell body
3
Q
Astroglia
A
provide link between neurons and capillaries, part of blood brain barrier
4
Q
Oligodendroglia
A
provide myelin for axons in CNS
5
Q
Microglia
A
phagocytic activity
6
Q
Schwann Cells
A
provide myelin for axons in PNS
7
Q
Nodes of Ranvier
A
where action potential is generated, gaps between schwann cells - speed up rate of conduction
8
Q
Resting Potential
A
-70mv; polarity due to unequal distribution of Na/K and (-) charged proteins inside
balance maintained by active transport and passive diffusion
9
Q
Action Potential
A
Stimulus increases permeability of neuronal plasma membrane - reach threshold - Na channels open (depolarize) - action potential - K channels open (repolarize) - refractory period - Na/K pump restore resting potential
10
Q
Synapse
A
connection between 2 neurons or neuron and effector cell
11
Q
Acetylcholine
A
excitatory and inhibitory
in NMJ, PNS (autonomic nervous system)
degraded by acetylcholine esterase
12
Q
Epinephrine (adrenaline)
A
catecholamine
excitatory in brain
SNS
13
Q
Norepinephrine (noradrenaline)
A
catecholamine
excitatory in brain
NMJ and SNS
14
Q
Dopamine
A
catecholamine
excitatory and inhibitory
CNS
15
Q
Serotonin
A
excitatory
In CNS (brain), GI
regulates behavior, attention, digestive processes
implicated in mood changes
16
Q
Glutamate
A
excitatory
17
Q
GABA
A
inhibitory
brain
18
Q
Autonomic Nervous System
A
Involuntary body functions (cardiac m, smooth m, glands, respiration)
Preganglionic fibers - in brain/spinal cord
Postganglionic fibers - outside CNS
19
Q
Sympathetic Nervous System (SNS)
A
fight or flight
increase general level of activity in body (cardio, respiratory, neurologic)
augmented by increased adrenal medulla secretions (adrenaline/noradrenaline) in response to stimulus by SNS
20
Q
Neurotransmitters in SNS
A
-preganglionic fibers - acetylcholine; cholinergic
-postganglionic fibers - noradrenaline; adrenergic
-post fibers in sweat glands/blood vessels of skeletal m
are cholinergic
21
Q
Receptors in SNS
A
Cholinergic (acetylcholine) - nicotinic (always stimulated)
Adrenergic
-alpha (norepinephrine)
-beta (nor and epinephrine) - heart muscle
22
Q
Parasympathetic Nervous System (PNS)
A
stimulates digestive system
aids recovery after sympathetic activity
ganglia located close to target organ
vagus nerve - innervates heart and GI
23
Q
Neurotransmitter in PNS
A
acetylcholine - both pre and post synaptic
24
Q
Receptors in PNS
A
nicotinic - postganglionic neurons, stimulated by acetylcholine
Muscarinic - effector organs, stimulated or inhibited by acetylcholine
25
Glioma
largest category of primary malignant tumors
| classified according to cell origin and location
26
Menningioma
tumor in meninges
27
Adenoma
tumor in pituitary
28
Pathophysiology of Brain Tumors
usually no well defined margins, invasive, difficult to remove
mass adds pressure and compresses tissues
inflammation around tumor- adds additional pressure
heriniation
29
Transient Ischemic Attacks (TIAs)
-results from temporary localized reduction of blood flow
in the brain (recovery in 24 hours)
-partial occulusion of an artery, small embolus, vascular
spasm, local loss of autoregulation
-may be warning before stroke
30
Cerebrovascular Accidents (CVAs) / Stroke
-Infarction of brain tissue due to lack of blood
*ischemia: occlusion of cerebral vessel (atheroma,
embolus) - 5 min can cause irreversible n cell damage
*intracerebral hemorrhage: rupture of cerebral artery in
pt with hypertension - more severe area of brain is
damaged, complicated by 2nd effects of bleeding
31
Cerebral Aneurysms
-localized dilation in the wall of an a. (usually at
bifurcation)
-aggravated by hypertension
-rupture, slow bleed - causes vascular type headache;
massive tear - leads to sudden fatal increase in ICP and
death
32
Meningitis
-bacterial infection in meninges of CNS (blood, direct
access through wound)
-infection spreads rapidly through the covering of the
brain
-diagnostic test: lumbar puncture to examine CSF,
identify organism
33
Brain Abscess
-localized infection (frontal or temporal)
-necrosis of tissue, edema of surrounding area
-from: spread of organisms from ear, throat, lung, sinus;
septic emboli; acute bacterial endocarditis; site of injury
or surgery
34
Encephalitis
-infection of parenchymal or connective tissue in
brain/spinal cord usually viral (spread by mosquitos)
-Western Equine - kids
-St Louis - older
-West Nile
-Lyme Disease - ticks, bulls eye lesion
*microbes spread through blood circulation
35
Rabies (hydrophobia)
-viral by bite of animal, transplantation of contaminated
tissues
-travels along PNS to CNS (necrosis, inflammation) to
salivary glands
*difficult swallowing, foaming at mouth, fear of fluids, -respiratory failure- death
-prophylactic immunization
36
Tetanus
-clostridium tetani (spores can survive in soil for years)
-infection through puncture would (rusty object)
-endotoxin enters nervous system - inhibits GABA
release
-Symptoms: muscle spasm, lock jaw, difficulty
swallowing, respiratory failure
37
Poliomyelitis (Infantile Paralysis)
-polio virus attacks motor neurons of spinal cord and
medulla
-Endemic in Wes/Central Africa - direct contact or oral
droplet
38
Multiple Sclerosis (MS)
-progressive demyelination of neurons in brain, SC and
cranial nerves - scars are formed (lesions, plaques)
-onset between 20-40, women 2:1
-Cause: unknown; genetic and environmental;
autoimmune; change in blood flow to neurons; infection
(clostridium perfringens)
-more common above 37th parallel - lack of vitamin D
39
MS Mechanism
-loss of myelin interferes with conduction of impulses in
affected fibers
-may affect motor, sensory, autonomic fibers
-occurs in diffuse patches in nervous system
40
MS Lesions
-early - loss of myelin in white matter of brain/SC, occurs
as inflammatory response
-plaques - develop later, become visible, larger areas of
inflammation and demyelination, vary in size
-remission - initial inflammation may subside, neural
function may return to normal for short POT
-recurrence - each causes additional areas of CNS to be
affected, neural degeneration becomes irreversible
function lost permanently
41
Parkinsons
-primary or idiopathic (after 60)
-secondary - due to encephalitis, trauma, vascular
disease, drug induced
-progressive degenerative disorder - decreased number
of dopamine secreting neurons in Substantia Nigra due
to neuronal death -- affects mvmt
42
Parkinsons Risk Factors
over 50
male
exposure to toxins, drugs (herbicides, pesticides, MPTP
43
Parkinsons Pathophysiology
-presence of Lewy bodies - clumps of aggregated
proteins with brain cells (causes neurons to die), alpha
synuclein found within
-diagnosed based on med history, neurologic exam
44
Amyotrophic Lateral Sclerosis (ALS)/Lou Gehrigs
-muscle wasting, degenerative hardening of lateral
corticospinal tract
-onset between 40-60 (men higher)
-affecting motor neurons (upper in cerebral - spastic
paralysis and hyperreflexia, lower in brainstem and SC
decrease m tone and reflexes
-death occurs due to respiratory failure (2-5 yrs after
diagnosis)
45
Myasthenia Gravis (MG)
-onset 20-30 (women more affected), men over 50
-autoantibodies to acetylcholine receptors at NMJ
(destroy and prevent m stimulation)
-S/S: m weakness in face and eyes, difficulty
chewing/swallowing, head droops
-use of acetylcholinesterase inhibitor- slows breakdown
of acetylcholine (will accumulate), increase change of
binding - strength increase (+ sign)
46
Huntingtons
-progressive neurodegenerative disorder (rapid, jerky
involuntary mvmts - autosomal dominant
-40+ years of age
-Trinucleotide repeat disorder - defective Huntington
protein (glutamine repeats 30-40) - binds to other
proteins, destabilizing and precipitating them (toxic to
neurons)
-progressive atrophy to brain (basal ganglia and frontal
cortex)
-depletion of GABA in basal nuclei
-levels of acetylcholine in brain appear to be reduced
47
Dementia
-progressive chronic disease with decreased cortical
function
-Causes: vascular disease (arteriosclerosis), infections,
toxins, genetic disorders
48
Alzheimers
-progressive cortical atrophy- neurofibrillary tangles (in
cytoplasm, disrupt metabolism); amyloid plaques
(outside cell, disrupt communication)
-affect women more than men
-more at risk with low education
49
AIDS Dementia
-common in later stages
-virus invades brain tissue
-may be exacerbated by other infections/tumors
-gradual loss of memory and cognitive ability, impaired
motor function
-kids with congenital HIV infection - brain frequently
affected, severe developmental delay
50
First Order Neurons
-Activation of a delta and c fibers in PNS causes action
potential and depolarizes the nerve that travels to cell
bodies in dorsal root ganglia and then to SC
-Functions:
*transduction - detection of noxious stimuli
*transmission - passage of resulting sensory input
from peripheral
51
3 Sources of Pain
-damaged cells
-secondary plasma leakage and lymphocyte migration &
leakage of neuropeptides from nerves
-nociceptors
52
Acute/Subacute Pain
-recent onset -
53
Chronic Pain
->3 months
-loose link with pain generator
-learned behavior, get positive reinforcement for pain
behavior
-no clinical findings to support pain
-pain associated with other forms of distressful stimuli
(anxiety, guilt)
-serves no biological purpose
54
Cutaneous Pain
sharp, superficial
55
Muscular Pain
deep aching, poorly localized, dull or sharp
56
Neurovascular Pain
throbbing, pulsing, pounding (migraine)
57
Neuropathic Pain
shooting, sharp, burning pain (usually comes on by itself)
58
Visceral Pain
-deep aching, pressing, boring, stabbing (feel outside of
affected organ)
-pain fibers from visceral organ, coming from somatic
tissues and converge in spinal cord - brain cant
determine if pain is coming from somatic or visceral
59
Complex Regional Pain Syndrome (CRPS)
Females>males
Pathogenesis
*abnormal activity of SNS --> sympathetic pain (chain
adjacent to spinal column, peripheral changes)
*gate control theory --> imbalance between
painful/nonpainful stimulus coming into SC
*Reflexive muscle spasm
60
CRPS Stage I
-acute (several weeks to several months (3)
-associate with SNS
-beginning signs of trophic changes
-occurs after noxious event
-mvmt worsens pain, immobility of limb is protected
position, limb maybe warm and red or dry and cool, pale
-may resolve spontaneously, responds well to treatment
61
CRPS Stage II
-last several months (3-6)
-over reactive SNS
-trophic changes of skin - limb edematous, cool, hair
loss, cracked brittle nails
-follows nerve injury
-persistent pain and exacerbated with stimulus, edema
spreads and joints become stiff, muscle wasting begins,
osteoporosis may begin, cutaneous and trophic
changes present
-treatments can be effective
-combo sympathetic block and treatment
62
CRPS Stage III
-lasts unlimited amt of time
-pain and sensory changes
-progressive atrophy of skin, subcutaneous tissue,
muscle and bone
-skin cool, thin and shiny
-rarely fully recover
-severe trophic changes, extreme immobility of affected
limb, edema has resolved, cutaneous tissues become
atrophied, changes in nails, xrays show osteoporosis,
resistance to treatment
63
Definite Diagnosis
```
-pain and tenderness in distal extremity
(disproportionate to injury)
-S&S of vasomotor instability
-swelling in extremity
-dystrophic skin changes usually present
```
64
Possible/Probably Diagnosis
- vasomotor instability and or swelling
- pain and mild-moderate tenderness may be present
- dystrophic skin changes are present
65
Doubtful Diagnosis
- unexplained pain and tenderness in an extremity
| - diagnostic blocks can indicate sympathetic involvement--> takes symptoms away
66
Aura (prictal or promodal)
subjective sensation or motor phenomenon that precedes and marks onset of seizure
67
Ictal Period
abnormal EEG activity - the seizure
68
Postictal Period
following seizure - confusion
69
Status Epilepticus
series of rapidly repeated epileptic convulsions without any period of consciousness between. may last hours or days
70
Generalized (tonic-clonic, grand mal)
-sudden cry, fall, rigidity followed by ms jerks, frothy
saliva, shallow breathing, bluish skin, loss of
bladder/bowel control
-usually 2-5 minutes
71
Absence (petit mal)
- blank stare lasting only a few sec
- most common in kids
- may result in learning disorder
72
Myoclonic
-sudden brief, massive muscle jerks that may involve the whole body
73
Atonic
- legs suddenly collapse, kid falls
| - 10sec
74
Infantile
- starts between 3mth and 2 yrs
| - go into fetal position
75
Partial (simple)
- preoccupied or blank stare
- experiences distorted environment - may see or hear things that aren't there
- feel unexplained fear, sadness, anger
76
Complex
- blank stare--> chewing and random activity
- appears unaware of surroundings
- no memory of what happened
77
Bone Remodeling Regulation
Stress imposed: weight bearing, m tension, disuse
| Hormones: GH- tissue growth, PTH- Ca
78
Osteoblasts
-bone forming
-make collagen and toher proteins of matrix
-promote calcification- depositions of ca salts in bone
-become osteocytes when trapped in matrix - stop
producing collagen
79
Osteoclasts
-bone resorbing
-secrete collagenase and other matrix degrading
enzymes - break down collagen
-regulated by PTH
80
Healing of Bone Fracture
-hematoma - fibrin network is formed - granulation tissue
forms
-phagocytic cells remove debris
-fibroblasts lay down new collagen fibers
-chrondroblasts form new cartilage
-osteoblasts generate new bone to fill the gap and
replace the callus
81
Rickets/Osteomalacia
-deficit of vitamin d from malabsorption, dietary deficits, -lack of sun exposure
-children(rickets) - leads to weak bones and other
skeletal deformities
-adults (osteomalacia) - leads to soft bones, resulting in
compression fractures
82
Paget's Disease
-excessive bone destruction with replacement by fibrous
tissue and abnormal bone
-occurs in adults over 40
-pathologic fractures are common (vertebrae)
83
Osteogenesis Imperfecta
-mutation in collagen I gene (autosomal dominant)
-extremely fragile bones
-short stature, blue sclera, loose joints, flat feet, brittle
teeth
-bowed arms/legs, kyphosis, scoliosis
84
Legg-Calve-Perthes Disease
-boys ages 2-12 (girls have it more severe)
-temporary reduced blood supply to head of femur in hip
joint
85
Osteomyelitis
- infection of the bone (staph aureus)
| - common in kids- associated in younger males
86
Osteosarcoma
- most common primary neoplasm of bone
- occurs in metaphysis of long bones of leg
- common in kids, adolescents and young adults
87
Ewings Sarcoma
- occurs in the diaphysis of long bones of leg
| - common in kids
88
Chondrosarcomas
- arise from cartilage cells
| - more common in adults over 30
89
Duchenne Muscular Dystrophy
-x-linked autosomal recessive disorder (boys)
-mutation of dystrophin gene - link between membrane and actin/myosin apparatus
-deficit of dystrophin - degeneration and necrosis of m
cell - skeletal m fibers replaced by fat and fibrous
connective tissue - cant replace functionally
(hypertrophic appearance of calf) - m function gradually
lost - cardiomyopathy commonly develops
-die from respiratory failure before 20
90
Osteoarthritis
-wear and tear joint disease (aging)
-weight bearing joints mostly affected w/ fingers
-articular cartilage damaged, surface rough and worn,
inflammation - edema
-tissue damage causes release of enzymes accelerating
degradation
-subchondral bone may be exposed and damaged
-bone spurs form
-cartilage fragments accumulate in joint space (becomes
narrower) - lose normal ROM - pain with weight bearing
91
Rheumatoid Arthritis (RA)
-autoimmune disorder (women)
-RF (antibody against IgG) - antigen/antibody complex
reacts w/ complement and deposits in tissue (type III) -
inflammation
-t cells stimulate - production of cytokines - inflammation
-synovitis
-pannus formation - granulation tissue spreads
(exacerbates condition -secretes enzyme destroying
cartilage)
-cartilage erosion - unstable joint
-fibrosis - calcifies and obliterates joint space - ankylosis - joint fixation and deformity
92
Juvenile Rheumatoid Arthritis (JRA)
-RF not present
-more acute onset
-inflammation in connective tissue including joints due to
antibody-antigen complex
93
Gout (gouty arthritis)
-results from deposits of uric acid crystals in joint- local
inflammation - cartilage damage
-often affects single joint (big toe)
-uric acid - waste product of purine metabolism
94
Ankylosing Spondylitis
- ankylosis - joint fixation
- spondylitis - inflammation of spinal joint
- sacroiliac and costovertebral joints
- men 20-30
- inflammation in low back then up spine
- kyphosis develops
- osteoporosis common
- lung expansion limited - rib mvmt reduced
