neurological system Flashcards
what are the two divisions of the nervous system?
central and peripheral
what does the central nervous system include?
brain and spinal cord
what does the peripheral nervous system include?
includes the 12 pairs of cranial nerves, the 31 pairs of spinal nerves and all thier branches
- acts as the messenger
- the PNS carries sensory (afferent) messages to the CNS from sensory receptors, motor (efferent) messages from the CNS out to muscles and glands, and autonomic messages that govern the internal organs and blood vessels
what is the cerebral cortex?
its the cerebrums outer later of nerve cell bodies
-responsible for governing thought, memory, reasoning, sensation, and voluntary movement
what is myelin?
is the white insulation on the axon that increases the conduction velocity of nerve impulses
does each part of the cerebrum have a hemisphere?
yes
what are the hemispheres divided into?
the frontal, partial, temporal, and occipital lobe
where is Wernicke’s area located?
whats it associated with?
in the temporal lobe
-associated with language and comprehension
what will happen is the Wernicke’s area is damaged?
- when damaged, it will result in receptive aphasia
- a person will hear sounds but has no meaning, like hearing a foreign language
where is the brocas’ area located?
what it associated with?
- located in the frontal lobe
- mediates motor speech
what will occur if the Broca’s area is damaged?
- expressive aphasia results
- the person can understand language and knows what they want to say but can only produce a garbled sound
what is synapse?
-site of contact between two neurons
what is the basal ganglia and where is it located?
- it controls automatic movement (eg, swinging of the arms when walking)
- it is buried deep within the two cerebral hemispheres
what is the thalamus?
- main relay station for the nervous system
- sensory pathways of the spinal cord and brain stem form synapse on thier way to the cerebral cortex
what is the cerebellum?
the lobe that is concerned with motor coordination of voluntary movements (eg, postural balance of the body)
characteristics of the spinal cord?
- long, cylindrical structure of nervous tissue approximately as big around as the little finger
- goes from medulla to L1 and L2
- main pathway for ascending and descending fibre tracts that connect the brain to the spinal nerves, and it mediates reflexes
what is a nerve?
-is a bundle of fibres outside of the CNS
what is peripheral nervous system composed of and what two groups is the PNS divided into??
- cranial nerves and spinal nerves
- these nerves carry somatic and automatic fibers
What is the somatic nervous system involve?
-innervates the skeletal (voluntary) muscles
what is the automatic nervous system involve?
-innervates smooth (involuntary) muscle (eg, cardiac and glands)
what does the diencephalon contain?
part of the forebrain, containing the epithalamus, thalamus, hypothalamus, and ventral thalamus and the third ventricle.
where do cranial nerve 1 and II extend from?
extend from the cerebrum
what is the third leading caused of death in Canada?
strokes
what does stoke prevalence increase with?
increases with age, hypertension, smoking and atrial fibrillation
what is a stroke?
a stroke, or cerebrovascular accident, occurs when the blood flow is interrupted to part of the brain
what are the two types of strokes?
- ischemic: when a clot blocks a blood vessel in the brain
- hemorrhagic: occurs when a blood vessel in the brain ruptures, pt has a much worse outcome
symptoms of a stroke?
- sudden weakness or numbness
- sudden confusion, difficulty speaking, changes in vision, trouble walking, dizziness or severe headache
how can atrial fibrillation cause a stroke?
In atrial fibrillation, the chaotic rhythm may cause blood to pool in your heart’s upper chambers (atria) and form clots. If a blood clot forms, it could dislodge from your heart and travel to your brain. There it might block blood flow, causing a stroke
what are some subjective questions for the neurological system?
- headaches? (anything that comes with it, is it sudden?)
- head injuries?
- dizziness / vertigo? ever feel lightheaded?
- seizures?
- tremors? do they worsen with anxiety?
- is weakness general or localized?
- incoordination?
- numbness or tingling? pins and needles?
- difficulty swallowing? when did this start?
- past history?
how long does a migraine last?
lasts longer than 4 hours
how long do concussion symtoms usually last for?
7 to 10 days
what is postictal period?
the period directly after seizure where pt is incontinent, sleepy, etc
how do you test cranial nerve one?
- olfactory nerve
- test sense of smell with those who report loss of smell, head trauma, or suspected intracranial lesion
- with pts eyes closed, occlude one nostril at a time and ask the pt to sniff
- use familiar scents
- normally a person can identify the scent through each nostril
- important to test ppl with Parkinson’s
how do u test the optic nerve II?
- Optic nerve
- test visual acuity and test visual fields by confrontation
1st: Snellen test (the chart)- first both eyes, then right then left
2nd: confrontation test: cover same eye and ask pt to look in your eye then move hands and ask pt to tell u when they can see the hand. tests peripheral vision
what is cranial nerve III?
oculomotor nerve
what is cranial nerve IV ?
trochlear
what is cranial nerve VI ?
Abducens
how do u test cranial nerves 3,4, and 5?
- check pupils size, regularity, equality, light reaction and accommodation (PERRLA)
- assess extraocular movements
- ICP cause sudden, unliteral dilation and nonreactivity of a pupil
- Nystagmus (back and forth oscillation of the eyes) occurs with damage to the cerebellum and brainstem
accommodation: get pt to follow finger towards nose. eyes should follow finger - cardinal position of gaze (follow finger in directions)
how to test cranial nerve V?
trigeminal nerve (6) -motor function: assess the muscles of mastication by palpating the temporal and massester muscle as the pt clenches the teeth sensory function: with the pts eyes closed, test light touch sensation by brushing a cotton wisp on designated areas of the patients face, forehead, cheeks, chin. have pt say "now" when they feel It
how to test cranial nerve VII?
Facial nerve (7) note mobility and facial symmetry as the pt responds to your requests to frown, close eyes tightly, lift eyebrows, show teeth and puff cheeks -loss of movement and asymmetry of movement occur both with CNS lesions (eg, CVA) and with peripheral nervous system lesions (eg, case of bells plasy)
how to test cranial nerve VIII?
acoustic nerve (8) -test hearing acuity by determining the pts ability to hear normal conversation, by the whispered voice test
how to test cranial nerve IX and X?
Glossopharyngeal (9) and Vagus (10)
-depress the tongue and note pharyngeal movement as the pt says “ahh”. the uvula and soft palpate should rise in the midline, and the tonsillar pillars should move medially
how to test cranial nerve XI?
Spinal accessory nerve (11)
- examine the sternomastoid and trapezius muscles for equal size
- check equal strength by asking the pt to rotate the head forcibly against resistance applied to the side of the chin
how to test cranial nerve XII
nerve 12- hypoglossal nerve
- inspect the tongue
- no wasting or tremors should be present
- note the forward thrust in the midline as the pt sticks out the tongue
how to inspect and palpate motor system
1) Muscles: assess size, strength, and tone
-atrophy: abnormally small muscle with wasted apperance, occurs with disuse, injury, lower motor neuron disease
-flaccidity: decrease resistance, hypotonicity
-spasticity and rigidity: types of increased resistance
2) Involuntary movements (tic, tremor)
-normally, no involuntary movement occurs
3) Gait:
-observe the pt walk 3-6m
Ataxia: uncoordinated or unsteady gait
Ask pt to walk heel-to-toe manner- normally, a person can walk straight and stay balanced
what is the Romberg test?
- ask the pt to stand up with feet together and arms at sides and ask the pt to close thier eyes and hold the position
- a positive Romberg sign is loss of balance that occurs when the eyes are closed
- a positive Romberg’s signs occurs with cerebellar ataxia (caused by multiple sclerosis, alcohol intoxication)
what is the finger to nose test?
-ask pt to touch the tip of his or her nose with each index finger
Neurology A test of voluntary motor function in which the person being tested is asked to slowly touch his nose with an extended index finger; the FTNT is used to evaluate coordination, and is altered in the face of cerebellar defects.
what is the heel-to-shin
- test lower extremity coordination by asking the pt to assume a supine position, to place the heel on the opposite knee, and run it down the skin from the knee to the ankle
- lack of coordination (heel falls off skin) occurs with cerebellar disease
- done on every stroke pt
how to test reflexes (called stretch deep tendon reflexes)
-measure the reflexes: reveals the intactness of the reflex arc at specific spinal levels, as well as normal override on the reflex of the higher cortical levels
-stimulate the reflect by directing a short, snappy blow if the relax hammer onto the muscles insertion tendon
4+- very brisk, hyperactive with clonus indicative of disease
3+- brisker than average, may indicate disease
2+average, normal
1+- diminished, low normal
0- no response
Clonus: a set of rapid, rhythmic contractions of the same muscle
what goes under dramatic growth during the first year of life?
an infants neurological system
what happens by two months of age?
a baby can smile responsively
what begins at 4 months of life?
babbling
what happens at aprox 9 months?
baby will start using one or two words (mama or dada) non-specifically
what is an early sign of cerebral palsy in an infant?
if affected infants, after you release the flexed knee, the legs quickly extend and adduct
what should happen after 6 months of age?
-baby should be able to hold head in midline when sitting, if not, baby should be referred for neurological evaluation
what should a neurological deficit caused by head trauma or disease process be monitored closely for?
-it needs to be monitored closely for deterioration in neuro status
what does a neurological exam include?
-level of consciousness
-motor function
-pupillary response
-vital signs
(start documentation with pts level of conciousness)
what should a nurse assess and note about LOC?
- a change in LOC is the most important factor in the examination
- it is the earliest and most sensitive index of change in the neurological status
- note the ease of arousal and the state of awareness or orientation
- note complacency in previously combative patient
how to assess motor function?
- ask the pt to lift the eyebrows, frown and bare teeth
- ask the pt to squeeze ur fingers
how to assess pupillary responses?
- note the size, shape, and symmetry of both pupils
- shine a light into each pupil and note the light reflex. both pupils should constrict briskly
- in a brain-injured pt, sudden, unilateral dilation and non-reactivity of the pupil is an ominous sight
- cranial nerve III (optic) runs parallel to the brain stem. when ICP pushes the brain stem down, it puts pressure on the nerve, causing pupil dilation
what to assess and note about vital signs?
A cushing reflex consists of signs of increasing ICP:
-a sudden elevation of systolic blood pressure with widening pulse pressure
-decreased pulse rate (heart rate)
-irregular respirations
Any changes are late consequences of rising ICP
what is the Glasgow coma scale
- divided into three areas: eye opening, verbal response, and motor response
- fully alert normal pt has a score of 15
- a score of 7 or less reflects coma
- lowest score is 3
what is peripheral neuropathy?
- loss of sensation
- loss is more severe distally (feet and hands)
- caused by diabetes, and chronic alcoholism
what is complete transection of the spinal cord
- complete loss of all sensory modalities below the level of lesion
- condition is associated with motor paralysis and loss of sphincter control
- caused by spinal cord trauma, demyelinating disorders, and tumors
what is decorticate rigidty?
DeCORticate - brings extremities to CORE of body
- occurs with brain injury (damage to cerebral hemispheres)
- adduction and flexion of the arms, tight against the thorax
- flexion of arms, wrists, and fingers (hands are closed shut)
- legs will be rotated internally
- feet will be plantar flexed
what is decerebrate rigidity?
- can indicate damage to brain stem
- arms will be adducted, stiffty extended
- palms will be flexed and pronated
- legs are extended that feet are plantar flexed (pointing)
