Neuro I Flashcards
function of the NS
controls and coordinates the body’s activities to maintain homeostasis
generation of sensory input to be processed
processing incoming data
generation of impulses that control voluntary and involuntary motor functions
storage of information
neurons
are the functional unit of the NS
cell body of neuron
main part of neuron, forms gray matter, center of the neuron
dendtites
recieve nerve impulses, branch like projections, carries impulses towards cell body
3 characteristics of a neuron
excitability
conductivity
influence
excitability
ability to generate an impulse
conductivity
ability to transmit an impulse within itself
influence
ability to influenec other neurons
axon
projects impulses away, found in myelin sheath
myelin sheath
speeds axon transmission, insulates & maintains white matter, nodes of Ranvier
axon with myelin sheath is myelinated or non myelinated
myelinated
multipolar neuron
multiple dendrites one axon
bipolar neuron
one dendrite, one axon
unipolar neuron
one process
lipid gives myelin what?
white color
insoluble in water-so need fat soluble Rx is needed to penatrate myelin sheath
classifications of neurons
structural-defined by the processes they have
functional-diretction of impulses conducted
sensory neurons
transmit nerve impulses toward CNS from peripheral sensory organs
Afferent-towards the brain (CNS)
motor neurons
transmit nerve impulses away from CNS to muscles, glands, organs
Efferent-away from CNS (brain)
Afferent
sensory neurons
Efferent
motor neurons
inter neurons
conduct impulses from one neuron to another
Sensory to motor or motor to sensory
two types of cells in the NS
neurons & neuroglia (glial) cells
Neuroglia cells
purpose: repair, support & protect neurons
more neuroglia than neurons
common source of primary tumors
types of neuroglia cells
astrocytes
ependymal cells
microglia
oligodendrocytes
produce the myelin sheath
astrocytes
found mostly in gray matter, Star of NS,
acumulate where neurons have been damaged
contribute to scar formation (gliosis)
feed neurons, from blood brain barrier
what forms the blood brain barrier
astrocytes
ependymal cells
aid in secretion and regulation of CSF
microglia
remove waste
can damaged nerves regrow
yes
in the CNS-it is limited
in the PNS- slow process
Nerve impulse conduction
travels by electrical transmission along axon and chemical transmission between neurons until it reaches its destination.
an electrical impulse is a result of what
K+ and Na+ ions moving in and out of the cells
Action potential
Our electrical impulses, has 3 states:
resting state
depolarization
repolarization
resting state of action potential
no impulse, increase of K+ within cell and decrease of Na+
depolarization
channels in cell membrance open & Na+ rushes in cell
repolarization
when the Na+ moves back out of cell and K+ moves back in cell
when the impulses reaches the end of the nerve fiber it is then transmitted across the junction between nerve cells at what?
the synapse
saltatory conduction
type of nerve conduction when nerve is myelinated
action potential jumps from one node of Raniver to the next, with saltatory conduction the Na+ and K+ ions only require to move in and out of cells at the Nodes of Tanvier
the synaptic transmission is compossed of what 4 components
presynaptic knob, synaptic cleft, neurotransmitter, and the receptor site
neurotransmitter
chemicals involved in the transmission of an impulse across the synapse
have excitatory or inhibitory
chemicals found in the neurotransmitters
acetylcholine
serotonin
norepinephrine
dopamine
name the two divisions of the nervous system
central and peripheral
the CNS consists of what
brain (cerebrum, brainstem, cerebellum)
and spinal cord
brainstem consists of what
midbrain
pons
medulla
the peripheral nervous system consists of what
12 pairs cranial nerves
31 pairs spinal nerves
autonomic nervous system (sympathetic & parasympathetic)
what are the protective structures of the NS
cranium
-14 facial bones, 8 cranial bones
foramen magnum
large hole, largest hole in skull, where brainstem and spinal cord connect
scalp
outermost layer of protection, fibrous, freely moving
dura mater
outer layer, thickest, toughest
arachnoid
middle layer, thin, delecate, loosly encloses the brain
pia mater
innermost layer, thin, vascular, mesh like
meninges
3, protective membranes that surround the brain and spinal cord
epidural space
between skull & dura mater, above dura mater
subdural space
below dura, between dura & arachnoid
subarachnoid space
between arachnoid & pia mater, holds CSF
name the layers of the protective structures of the nervous system
skin
bone
epidural space
dura mater
subdural space
arachnoid membrane
subarachnoid space
pia mater
brain
falx cerebri
dural fold that separates the 2 cerebral hemisphers
tentorium cerebelli
double dura later fold between the cerebral hemispheres and cerebellum
allows for some expansion
supratentorial
surgery above the tentorium (cerebrum)
infratentorial
surgery below the tentorium
(cerebella)
CSF
cerebrospinal fluid
clear, colorless, odorless
fills ventricles and subarachnoid space of brain and spinal column
no RBC in CSF
what is the purpose of CSF
protects and cusions
shock absorber
what is CSF made of
H2O, protein, O2, CO2, Na, K, Cl, glucose
CSF flow
termed the 3rd circulation,
it is a closed system
absorbed by the arachnoid villi projections
the brain requires ____% of the bodys total oxygen and glucose requirements
25%
Venous drainage of the brain
exits via 2 vascular channels called dural sinuses which empty into the jugular veins
has NO valves, gravity is needed for drainage of blood
where does the arterial supply for the brain enter
foramen magnum
the anterior circulation is supplied by
the common carotid -external & internal carotid
the posterior circulation of the brain is supplied by
the R & L subclavian artery which branhes into R &L vertebral arteries then come together again to make the basiliar artery
circle of willis
allows blood to circulate from one hemisphere to another, acts as a safety valve, protects from occlusion or differential pressures, formed by the basilar artery and internal carotids
blood brain barrier
a pysicological barrier between blood capillaries and brain tissue, made of astrocytes and tight capilaries, protects brain from potential damaging agents, chemicals and toxins
what medications can get through the BBB
lipid souluable
3 divisions of the brain
cerebrum, brain stem, cerebellum
gyrus
convolution (folds) on the surface of the brain, increases surface area
fissure
deep seperations in the cerebral hemispheres
great longitudinal fissure
divides the cerebral hemispher into right and left
cerebrum
largest part of brain, contains nerve centers associated with sensory, motor and higher mental functions
cerebral cortex
outer layer of the brain, it is the gray matter, has billions of neuron cell bodies & dendrites
Made of cell bodies
2 hemispheresof the cerebrum
each hemisphere has 4 lobes
-frontal, parietal, temporal, occipital
have corresponding cortex layer
the white matter of the brain is made up of?
axons
frontal lobe of the brain
contralateral (left controls right, right controls left)
function: ig motor movements, memory, higher cognitive function (problem solving), judgement, broca’s area
Broca’s area is responsible for
expressive speech-ability to form words
damage to this area can cause stuttering, expressive aphasia
can be impaired by trauma or alcohol
cerbral dominacny for 90% of persons is which lobe
left frontal lobe
parietal lobe
primary sensory area
interprets sensory thought-touch, position
body awareness
spatial awareness-ability to comprehen out position in relation to our enviornment (so we are not clumsy)
temporal lobes
auditory reception-hear and interpret sound
Wernicke’s area-reception of speech, ability to understand written & spoken language
receptive aphagia
Wernicke’s area of the brain
temporal lobe
helps with ability to understand writeen and spoken language
damage to the temporal lobe can cause
occipital lobe
primary receptive area for vision and visual association
damage to this area will cause to not understand what is seen
basal ganglia
base/clump of neurons
deep in the hemispheres
responsible for execution, initiation, completion of voluntary movement and autonomic movements (blinking)
diencephalons
area of the brain just above brainstem
includes thalamus, hypothalamus
thalamus
major relay station for all sensations
hypothalamus
regulates autonomic nervous system
effects temperature, fluid balance, reproduction, metabolism, and hunger
limbic system
effects feeding and sexual behaviors and emotional responses
brain stem
connects spinal cord with cerebrum and cerebellum
contains ascending and descending pathways for impulses to go to and from the brain
attachment for crainal cerves III-XII
brainstems 3 main structures
midbrain, pons, and medulla oblongota
what is the medulla oblongata
primary rhythm center, responsible for RR, HR, BP cardiac function
Reticular formation
RAS
special neurons that control the sleep-wake cycle
reticular activating system controls what
attention span, conciousness, damage could cause issues with LOC
cerebellum
located in posterior fossa, above brainstem, below the occipital lope
responsible for fine motor moements, balance, truckal stability
spinal cord
continuious with the brain stem, mass of nervous fibers, extends from C1-L1
what is the spinal cord protected by
meninges (dura mater, arachnoid & pia mater)
and vertebrae
gray matter in the spinal cord
anterior/ventral-wider arms of the H
where primary motor neurons are located, hold motor tracks
the white matter is made up of what?
what does it do?
myelinated nerve tracks, carry messages between the brain and the perioheral muscles
Sensory
afferent messages ascending tracks, messages to the brain
motor
efferent messages, descending tracks, messages go down or away from the brain
ascending tracts of the spinal cord do what
carry sensory input to the brain from the periphery
such as touch, pressure, vibration, and kinesthesia
spinocerebelalr tracts effects what
muscle tension and body positon
nothalamic tracts effects what
temperature and pain
descending tracts in the spinal cord do what
carry motor messages
corticospinal
descending tract, cortex of frontal lobe & crosses at the medulla
its responsible for voluntary motor function
lesions in the upper motor neuron cause what
weakness, paralysis, hyperflezia, spastic muscle tone
lesions in the lower motor neuron cause what
weakness, paralysis, decrease muscle tone (flacid), hyporeflexia
do reflexes have cerebral input
NO
monosynaptic reflex steps
- receptor organ:arrival of stimulus& activiation of receptor
- sensory neuron: activation of sensory neuron
- information processed in spinal cord
- motor neuron: activation of motor neuron
peripheral nervous system includes what structures
all neuronal structures that lie outside of the CNS
- crainal nerves
- spinal nerves
- autonomic nervous system
which crainal nerves start at the brain stem
III-XII
Cranial Nerve I
Olfactory
- smell
- sensory
Oh, Oh, Oh To Touch And Feel A Guys Vein And Hotdog
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Trigeminal
- Abduncens
- Facial
- Acoustic
- Glossopharyngeal
- Vagus
- Accessory (spinal)
- Hypoglossal
Crainal nerve II
Optic
- sensory
- vision
Snellen chart
Crainal nerve III
- oculomotor
- motor
- eye movement, eye lid, pupil constriction
What crainal nerves are tested together
III, IV, VI
&
IX & X
crainal nerve IV
Trochlear
- motor
- eye movement
Crainal nerve V
Trigeminal
- sensory & motor
- facial sensation, chewing, corneal reflex
crainal nerve VI
Abducens
- motor
- eye movement
crainal nerve VII
Facial
-sensory & motor
taste & facial expressions
crainal nerve VIII
acoustic
- sensory
- heaing and equilibruim
Crainal nerve IX
Glossopharyngeal
- sensory and motor
- taste on posterior part of tounge, swallow & gag
Crainal nerve X
Vagus
-smooth muscle of palate, pharynx and layrnyx, controls parasympathetic NS
Crainal nerve XI
Accessory (spinal)
- motor
- muscles of neck
Crainal nerve XII
Hypoglossal
- Motor
- Toungue movement
how many spinal nerves are there?
31 pairs
the dorsal root is the attachment for what
sensory fibers
the ventral root is the attachment for what
the motor fibers
dermatomes
area of skin that issupplied by sensory fibers of sensory root
myotome
cauda equina
horse tail, where the nerves come off
autonomic nervous system
effects involuntary function of caridac, smooth muscle, and glands
2 divisions of the autonomic nervous system
sympathetic and parasympathetic NS
sympathetic nervous system
Fight of Flight
causes casoconstriction of blood vessels,
increase BP< RR< HR
originates at T1-L2 (Thoraciolumbar division)
parasympathetic nervous system
rest and digest
conserves and stores bodys energy stores
decreases BP, HR, RR increases parastalsis
orginates in brain stem and sacral (craniosacral)
nursing assessment of the conscious patient contains an assessment of what?
mental status
LOC
crainal nerves
motor and sensory function
cerebellar function
reflexes
what kind of subjective data would you gather from a conscious patient
chief complaint (open ended ?’s)
medical history
any exposures to toxins, chemicals, etc..
learning disabilities?
recent and remote Hx
speech
nutritional/elimination
activity/sleep pattern
cognition
who will do an in depth assessment of speech
speech pathologist/therapist
expressive aphasia may show damage to what area of the brain
Brocha’s (frontal lobe)
know what they want to say but they are unable to express or say
receptive aphasia may show damamge to what area of the brain
Wheinki’s area (temporal lobe)
can form words but not cordinated
Romberg’s test
feet together, arms at sides, eyes open then closed to show position sense and equilibrium
(swaying = +Rombergs)
cerebrallar function tests are used to show what
balance and coordination
- finger to exaimers finger
- walk heel to toe
- touch finger to nose
- Romberg’s test
incontinence with back pain shows possible damage to what crainal nerve
Vagus
-X
what objective dada would you get with a conscious patient
mental state
crainal nerve functions
motor function
verebellar function
sensory function
reflex function
abnormalities with motor function
atrophy
contractures
tremors
twitching
hypertonia
hypotonia/flaccidity
2 point discrimination
2 points of an instrument on the same area
can they feel both
stereognosis
ability to ID a common object with just feel
astereognosis
inability to ID a common object with just feel
graphesthesia
ability to ID #’s and letters by feel when they are drawn on a body part with a finger
babinski
when stoke lateral aspect of foot
if you have fanning of toes = + Babinski
geriatric changes with nervous system are
loss of neurons (decrease in brain weight)
decrease in efficiency with regulating temperature
decrease blood flow
decrease of CSF (cushing and nurishment)
loss of myeling (decrease reaction time)
muscle atrophy
dinimished sense
slow reflexes
sleep patterns alter
full conscious
alert, oriented, follows commands, answers ?’s
confusion
disoriented to time and place
lethargy
oriented but slow speech, mental process and motor activity
obtundation
difficult to arose requires constant stimulus to answer ?’s and floow commands
stupor
vigorous stimulation and doesnt follow commands
coma
sleep like state, doesnt respond to stimulus
glascow coma scale
calculate neuro status
15=fully intact
7=a level of coma
3 or less = deep coma/death
decortication
abnormal flexion response
towards cored
damage above brain stem
decerebration
abnormal extension response
brainstem disfunction
what crainal nerves are checked in a unconscious patient
III (oculomotor)
V (trigeminal)
IX & X (gag reflex)
pupil changes of slow or absent can indicate what
increase of crainal pressure or cerebral herniation
oculocephalic reflex
unconsious pt only
eyes are held open, head is turned side to side,
if the eyes move with the head = ABNORMAL
oculovestibular reflex
administer cool fluid into the pts ear, if the eyes deciate to side of the injection that is NORMAL
In the NIH stoke scale you want the over all # to be what
lower the better
Xray will indicate what
evaluate skull and vertebrae for abnormalities, fx, calcifications..etc
cerebral angiography
contrast medium into femoral artery
*flushing or warm feeling
visualize intracranial and extracrainal blood bessels
for occlusion, patency, narrowing, stenosis, abnormal bleed
*assess for bleeding, PT must lay flat, check 6 p’s, increase fluids to flush dye out
CT Scan
cross sectional view of head and brain
bone=white
CSF=black
brain=gray
ID changes in tissue density, abnormal size, shape and location of structures, edema, infarction, growth, clots, bleeding, skull fx
Lay motionless for 15-20 minutes, murmur noise
MRI
NO RADIATION (use magnets)
clearer imagesof soft tissues
sharp detailed cross sections of brain,
LOUD, @ 1 hour, wear headphones
MRA
type of MRI to check blood flow and abnormalities, small vessels may be difficult to view
myelogram
visulize spinal column and subarachnoid space using a contrast medium (lumbar puncture)
not done frequently
CSF analysis
obtain by lumbar puncture
check for RBC
below L3
have transient pain (pain/twitching down leg)
manometer
used during lumbar puncture
measures pressure of CSF
pt is asked to extend thier legs
EEG (electroencephalopgraphy)
electordes are placed on scalp with paste mixture
shows electrical activity of brain
-seizures, sleep disorders, parkinsons, etc
why should you eat prior to a EEG
because low glucose can alter the brain patterns
EMG (electromyography)
needle electrodes are plcaed in muscle to measure nerve conduction
muscle at rest = no electrical activity
pt will have pain
evoked potentials
measures the electrical signals along nerve pathways
measure amount of time it takes a impulse to move through pathway
- visual
- auditoy
- somatosensory (electric shock)
PET
3D image of brain function
given a chemical substance that is inhaled
blood flow, brain metabolism
carotid duplex
blood flow velosity in carotid artery, looks for blockages or occlusions
transcrainal doppler
image flow velocity of intracrainal blood vessels (temporal/occipital area)
inner ear does what
sends into to brain (hearing & equilibrium)
auricle
is the outer part of the ear
AKA pinna
made of cartliage, collevts and transmits sound waves and sends them to tympanic membrane
external auditory canal is lined with what
fine hairs, sebacous glands and ceruminous glands
cerumen
ear wax
protective helps provent debris from entering the ear
tympanic membrane
eardrum
concave shape, shiny, pearly gray translucent
sound waves conducted by the tympanic membrane then the ossicles
ossicles
malleus, incus, stapes
what is the middle ear connected to
nasal pharnx by the eustacian tube
eustachian tube
helps to equalize pressure between outter and inner ear
to open you must yawn or swallow
inner ear contains
vestubule, cochlea, semicircular canals, membranous labyrinth, bony labyrinth
membranous labyrinth
holds semicircular canals, and orgin of cortie
surrounded by endolymph fluid
endolymph fluid
allows structures to float to prevent damage if have head injury
vestibule
separets cochlea from semicircular canals
entrance to inner ear
communicates between cochlea and semicircular canals
semicircular canals
sensory organs that help with equilibrium
if have excess of fluid in these canals have balance issues
cochlea
snail shape
within is the orgin of cortie
organ of corti
lined with tiny hair cells, when they are stimulated they transmit a electrical impulse of acustical nerve
transmission of sound is measured in what
dB and Htz
bone conduction bypasses what
external and middle ear
your equilibrium is controlled by what
vestibule amd semicircular canals
dynamic equilibrium
ability to remain stable with movement
static equilbrium
orientation to body to ground so we can maintain our posture
nystagmus
abnormal fine eye twitching
report if blurry vision or fluttering feeling
vertigo
sensation that you are spinning in space or moving
vertigo will contimue while you lay down, where dizziness will go away
hibituation
you should continue the activity in small incriments to acculmate yourself and it will eventually get better
what disease if a pregnant women has can affect the babies hearing
rubella
conductive hearing loss
problem with sound wave condiction
-hardening of ossicles
sensorineural hearing loss
problem with inner ear
cochlea, hair cells, nerve (acustic)
Presbycusis
hearing loss associated with aging
ear changes in the elderly
- eardrum thickens, decrease ability to produce sound waves
- in hair and cerumen
- califying of ossicles
- damage to hair cells over time
tinnitus
ringing of the ears
Rinne Test
vibrating fork is placed on patients mastoid bone then when they no longer hear sound the fork is moved to front of pinna
positive Rinne test
air conduction time is greater than bone conduction
Weber test
stem of an activated tuning fork is placed on the center of the skull
conductive hearing loss in weber test
sound will lateralize to the poor ear
sensorineural hearing loss in the weber test
sound will lateralize to the good ear
audiometry
sound proof room, sounds vary in frequency and intensity
single most important test for evaluating hearing
electrostagmography
irrigate the ear and watch for eye movement
otologist
MD, Dx ear problems, perform surgery
otolaryngologist (ENT)
perform surgery
audiologist
eval & Tx ear disorders
not an MD
for ear drops how do you palce pt
lay on unaffected side, pull ear up and back on aduld, down and back on kid
how should you place a pt for ear irrigation
pt should lean towards you
orbit of eye
bones, protective socket for eyeball
palpebral conjunctiva
eyelid, mucous membrane that lines eyelid
what is the purpose of the conjunctiva
secretes mucous and oil, keeps cornea moist clear and free of infection
function of lacrimal system
allows tears to flow from outer to inner eye
puncta
tiny openings in the lids that let tears drain into lacrimal duct, nose
pathway for vision is
light passes through cornea, pupil, posterior cavity, focused on retnia and then the optic nerve
ciliary muscles help with what
help to change the shape of the lens for focusing (accomadation)
what controls the constriction and dilation of the iris
sphincter and dilator iris muscles
sclera
toughest, thickest, outer layer
helps maintain shape and protects
white part of the eye
can be blue in children and yellow in african americans and the elderly
cornea
transparent and avascular
initial means of refraction = crude focus
iris
colored part of the eye highly vascular
choroid
below sclera
supplies blood to retinal layer
lens
directly behind pupil
biconvex
bends light rays to focus on retina
retina
made up of neurons, inner most layer
if it is damaged you have vision loss
converts image to a form that the brain can understand and process into vision
rod vs cone
rod-receptors for dim light
cones-color receptors
macula
area of retina responsible for central vision
free of blood vessels bc has concentraded cones
fovea centalis
center of macula
most sensitive area
sharpest visual acuity
optic disc
depression the optic nerve exits at the optic disk also where we get blood flow
anterior chamber
from cornea ro lense
posterior chamber
from iris to lense
light ray that enters the eye will travel through…
cornea
aqueous humor
pupil
lens
vitrous humor
retina
optic disc, nerve
optic chiasm
occipital lobes
pseudopedrin can do what to the eyes
dilate the pupils
longterm corticosteriods can put a pt at risk for what
glacoma and catarects
ptosis
drooping of eyelid
anisocoria
unequal pupil size
exopthalmos
bulging of eye
enopthalmos
sunken apperance of the eye
snellen chart
20 feet from chart and read the smallest letters, at least 50% of the letters must be correct
OD
right eye
OS
left eye
OU
both eyes
Jaegar chart
near vision
hold about 14 inches away
refractometry
multiple lenses used with snellen chart
opthamoscope
dark room, dilate eyeevaluating optic disk, retina and macula
absence of red reflex
abnormal
looking for a reflection of light off retina
intraoccular pressure
mearsured with puff of air
normal is 10-21 mHg
Ishihara test
dosts are arranaged in a simple pattern to test for color blindness
ophthalmologist
MD who provides total care, surgery etc
optometrist
dont perform eye surgery
optician
grinds and fits lenses according to a Rx
arcus senilis
milky white or yellow ring aound iris
due to cholestrol deposits
eye medications need to be spread out for how long
in between multiple eye medications 5-10 minutes
ointments
stay on longer
thicker
but can cause blurry vision
