Exam 1 Flashcards
4 main functions of the nervous system
maintain homeostasis
program reflexes
voluntary control of movement
memory and learning
parasympathetic nervous system
slow heart rate
constricts bronchi
contracts bladder
sympathetic nervous system
increase heart rate
dilate bronchi
inhibits bladder contraction
cell body of neuron
soma with nucleus
axon hillock
transition part of cell body and axon
generates AP
synapses
between two neurons
anterograde
away from soma
retrograde
towards soma
how are neurons classified?
structure
number of processes
myelination
function
bipolar neuron
interneurons in spinal cord
sensory neurons
two processes
unipolar neuron
sensory neurons in spinal and cranial nerve ganglion
one process
multipolar neuron
motor neuron
anterior horn cell
many processes
pyramidal cells
pyramid shape
2 dendritic trees
excitatory in cortical structures
plasma membrane makeup
phospholipid bilayer with phosphate hydrophilic heads and lipid hydrophobic tails
leak channels
difference in ion concentration
modality gated
sensory stimuli: light, sound, touch
ligand gated
neurotransmitter
voltage gated
change in charge
intracellular fluid
more potassium
organic anions
negative and positive proteins
extracellular fluid
more sodium
more calcium
chloride
resting membrane potential
-70mV polarized
movement in resting membrane potential
selective permeability to potassium
sodium potassium pump
anions inside cell
sodium potassium pump
3 sodium out
2 potassium in
local potential
spreads short distance
receptor potential
modality gated, long distance
How does large depolarization change cell charge
make it less negative (more positive)
charge needed for action potential
+15
cell needs to be at -55
where in the cell is action potential fired
axon hillock
what are sodium and potassium channels doing at resting potential
closed
what are sodium and potassium channels doing at threshold potential
sodium channels open and let sodium into the cell
what are sodium and potassium channels doing at depolarization
more sodium channels open and sodium goes into thee cell for about 1ms and then they close
what are sodium and potassium channels doing at repolarization
potassium channels open and potassium exits the cell
what are sodium and potassium channels doing at hyperpolarization
potassium channels stay open and it continues to leave the cell
absolute refractory period
sodium channels shut off soon after highest point of depolarization and no action potential can occur
relative refractory period
during repolarization and hyper polarization, a larger stimulus is needed to cause action potential
what is the conduction velocity of an unmyelinated axon
square root of diameter at the axon
what is the conduction velocity of a myelinated axon
proportional to the diameter of the axon
where do action potentials occur in myelinated neurons
nodes of ranvier
what do glial cells do
protection and support neurons
maintain homeostasis, clean debris, form myelin
what do astrocytes do
help with communication
scavengers
nutrition
blood brain barrier
what do microglia do
developing brain and help neural niche and pruning
what is a primary RF is many diseases including demyelination disorders?
oxidative stress
oxidative stress
disturbance is the balance between production of reactive oxygen species (free radicals) and antioxidant defenses
examples of peripheral demyelinating diseases
peripheral diabetic neuropathy
chronic inflammatory demyelinating polyradiculoneuropathy
POEMS
Charcot Marie Tooth disease
causes of PDN
compression, genetics, social and lifestyle (chronic alcohol consumptions, smoking, obesity)
pedal parasthesias
pins and needles and tingling
A1c testing
measures percentage of hemoglobin proteins that are covered in sugar
normal is less than 5.7%
lab testing for PDN
serum glucose
A1c
complete blood count
erythrocyte sedimentation rate
signs of PDN
decreased light touch sensation
loss of ankle reflexes
GI problems (discomfort, dysphagia, nausea, constipation, diarrhea)
Cardiac problems (hypotension, sinus tachycardia, variable HR, syncope)
Bladder problems (weak system, straining to void, incomplete emptying)
Skin (heat intolerance, gustatory sweat, diaphoresis)
Nervous (carpal tunnel, radiculopathy, lumbosacral and cervical neuropathy)
DPN treatment
improve glycemic control
pharmacological treatment of symptoms disturbing sleep or ADLs
PT
Chronic inflammatory demyelinating polyradiculoneuropathy
acquired immune mediated demyelinating disease of PNS with progress loss of motor and sensory functions
what happens in CIDP
immune system attack myelin sheath of PNS which causes segmental demyelination and axonal degeneration
CIDP symptoms
tinging/ numbness of extremities
symmetrical weakness/ parasthesia of arms and legs
loss of reflex
fatigue
ataxia
limb incoordination
diagnosis of CIDP
elevated CSF protein w/o increased leukocyte
MRI evidence of gadolinium enhancement or nerve root plexus hypertrophy
primary demyelination
improvement following immunotherapy
treatment of CIDP
intravenous immunoglobulin
corticosteroids
therapeutic plasma exchange
immunosuppressive therapy
CIDP and PT
demyelination means less recruitment of muscle fibers for a given task so be careful of overexertion
manual therapy to reduce contractures and improve ROM
gait retraining, balance and exercise programs
What happens to pt. with CDIP taking immunotherapy?
improvement right away
dysphagia
problems swallowing
gustatory sweating
sweating while eating
extreme diaphoresis
sweating
dysphesia
stimulus that normally isn’t painful is painful
stocking glove distribution
longest sensory nerves affected first (toes, fingers, feet, hands)
POEMS
Polyneuropathy
Organomegaly
Endocrinopathy
Monoclonal Protein
Skin Change
Sclerotic bone
Polyneuropathy cause
plasma cell proliferative disorder
Neoplasms
proliferative disorder of plasma cells
originate in bone marrow
abnormal secretion by the plasma cells of homogenous immunoglobulin with paraprotein idiotype
who gets POEMS
males over 60
symptoms of POEMS
sensory: tingling, paresthesia, coldness in feet, proprioception disturbances
motor: symmetrical severe weakness of extremities that progress distally
nerve conduction: high serum concentration of vascular endothelial GF
hepatomegaly
testicular atrophy and gyenocomastia
DM
hyperpigmentation and hypertrichosis
treatment of POEMS
high dose chemo
stem cell transplant
corticosteroids
low dose alkylation therapy
PT and OT
Survival/ prognosis of POEMS
13.8 years
cardiorespiratory or renal failure
CMT
hereditary gene abnormality affecting Schwann cells and peripheral nerve axons
CMT symptoms
motor: weakness and paralysis or foot/leg, foot drop, high stepped gait, falling, foot deformities, atrophy
sensory: reduce temp/ touch sensation, muscle cramping, contractures, scoliosis, hip displacement
CMT diagnosis
nerve conduction studies
EMG
nerve biopsy
genetic testing
CMT treatment
pain meds
PT
OT
orthopedics
