Neuro Flashcards
what does the nervous system consist of?
brain, spinal cord, and peripheral nerves
major sensory organs
eyes and ears
what is the nervous system divided into
cns and pns
pns consists of what
12 cranial nerves, 31 pairs of spinal nerves, and the autonomic nervous system
basic cell of the nervous system
neuron
short, branch-like extensions on the cell body that carry impulses to the cell body from other cells
dendrites
controls the function of the neuron
cell body
single, long projection that carries impulses away from the cell body
axon
white fatty substance that protects the axon
myelin sheath
nerves with a myelin sheath
myelinated (white nerve fibers)
nerves w/o myelin sheaths
unmyelinated (gray nerve fibers)
impulses move from one neuron to another across a ____
synapse
a chemical ____ such as acetylcholine either helps or stops the impulse from crossing the synapse
neurotransmitter
_____ neurons carry impulses from the skin and muscles to the CNS
sensory (afferent)
____ neurons carry impulses from the CNS to the muscles for contraction or glands for secretion
motor (efferent)
what is the control center of the nervous system
brain
what is the brain protected by
bony skull and membranes
the outer layer of the meninges
dura mater
the middle layer of the meninges
arachnoid
the inner layer of the meninges (directly attached to the brain)
pia mater
where are arterial blood vessels located
epidural space (b/t skull and dura mater)
where is csf found
Subarachnoid space (b/t arachnoid and pia mater)
4 major regions of the brain
cerebrum, diencephalon, brainstem, cerebellum
largest area of the brain that is separated into the right and left hemispheres
cerebrum
deep grooves in the cerebrum
fissures
what connects the hemispheres and allows for communication
corpus callosum
left hemi is responsible for what
speech, problem solving, reasoning, and calculations
right hemi is responsible for what
visual-spatial info, art, music, and surrounding physical environment
the ____ contains gray matter, while the rest of the cerebrum is made up of white matter
cerebral cortex
each hemi is divided into 4 lobes
frontal, parietal, temporal, occipital
____ contains the thalamus and hypothalamus
diencephalon
what does the hypothalamus regulate
temp, fluid balance, thirst, appetite, emotions, and the sleep-wake cycle
what does the brain stem consist of
midbrain, pons, medulla oblongata
___ is the center for auditory and visual reflexes
midbrain
___ controls respiration
pons
___ controls hr, bp, resp, coughing, swallowing, and vomiting
medulla oblongata
___ is connected to the brain stem and has two hemispheres, and coordinates involuntary muscle activity and fine motor movements as well as balance and posture
cerebellum
a clear, colorless liquid that protects the brain and spinal cord from trauma. It also provides a place for nutrient exchange an waste removal
csf (cerebrospinal fluid)
daily production of csf (mL)
125-150 mL
what is in csf
high glucose, few wbc, and no rbc
how much blood does the brain get per/min
750mL/min (20% od cardiac output)
what is the brain’s only source of energy
glucose (cannot store O2 or glucose, so needs constant supply)
two arterial systems that supply the brain
internal carotid (cerebrum) and vertebral arteries (cerebellum and brainstem)
the major arterial supplies of the brain are connected by smaller arteries forming a ring called ____
circle of Willis (alternative routes when artery is blocked)
cerebral veins drain venous blood into the ____
jugular veins
composed of astrocytes that are joined by tight junctions which decreases permeability so that harmful substances in the blood cannot enter the brain
blood-brain barrier
what can pass through the bbb
lipids, glucose, some amino acids, CO2, O2, and water
what cannot pass the bbb
urea, creatinine, some toxins, and most antibiotics
where does the spinal cord exit the skull
foramen magnum
what protects the spinal cord
vertebral column
vertebral column consists of what
C 7, T 12, L 5, S 5, 4 fused coccyx
the ventral horn consists of ___ neurons
motor
the dorsal horn consists of ___ neurons
sensory
the lateral horn consists of ___ neurons
sympathetic
____ matter forms ascending and descending pathways known as spinal tracts
white
these carry messages to and from the brain: ascending sensory pathways and descending motor pathways
spinal tracts
the pns is divided into ____ and ____
sensory and autonomic nervous systems
connects the skin and muscles to the cns
sensory ns
controls visceral organs and some glands
autonomic ns
31 pairs of spinal nerves
C8, T12, L5, S5
sensory fibers are in the ___ root
dorsal
motor fibers are in the ___ root
ventral
an area of skin supplied by a single spinal nerve is called
dermatome (useful for locating pain and neurologic lesions)
which cranial nerves just control sensory function
I, II, VIII
how many pairs of cranial nerves
12
a part of the PNS that is responsible for maintaining the body’s internal homeostasis
ANS
the ANS regulates what
respiration, HR, digestion, urinary excretion, body temp, and sexual function
two divisions of the ANS
sympathetic and parasympathetic
prepares for the body to handle stress “fight or flight”
sns
operates during non-stressful events to conserve the body’s energy “rest and digest”
psns
pneumonic for the cranial nerves and their function
oh oh oh to touch and feel very good vagina ah ha
some say marry money but my brother says big brains matter more
protect the eyeballs
eyelids and eyelashes
thin mucous membrane that lines the inner surface of the eyelid
conjunctiva
secretes and drains tears to cleanse and moisten the eye’s surface
lacrimal apparatus
tears are produced by what
lacrimal gland
where do tears drain
lacrimal ducts (then into nose)
when the cornea is touched the eyelids blink and tears are secreted
corneal reflex
colored part of the eye, regulates light entering the eye by controlling the size of the pupil
iris
a transparent structure behind the pupil that can change shape to focus light onto the retina
lens
vascular layer of the eyeball
choroid
the innermost lining of the eyeball and contains millions of light receptors called rods and cones
retina
light sensitive and allows us to see in dim light
rods
allow us to see color and provide a sharper image
cones
the area where light passing through the pupil and lens focuses on the retina
macula
the center of the macula that allows for detailed color vision
fovea centralis
the optic nerve enters the eye at
optic disk
the eye has two interior cavities
posterior and anterior cavity
posterior cavity behind the lens contains clear gelatinous ___
vitreous body
anterior cavity is divided further into ___ and ____
anterior (b/t cornea and iris) and posterior (b/t iris and lens) chamber
the anterior cavity is filled with ___
aqueous humor (constantly formed and drained to maintain relative pressure within the eye)
___ at the junction of the sclera and the cornea (limbus) allows aqueous humor to flow b/t the anterior and posterior chambers
canal of Schlemm
to change the point of focus from far to near, the lens changes shape, the pupil constricts, and the eyes converge
accommodation
where do the optic and the cranial nerves meet
optic chiasma
impulses generated in the retina travel to the ____ in the occipital lobe of the brain
visual cortex
the visual fields of each eye overlap considerably and each eye sees a slightly different view allowing for ___
depth perception
2 primary functions of the ear
hearing and maintaining balance
3 areas of the ear
external, middle, and inner
glands in the auditory canal secrete what
cerumen (traps debris, protecting the tympanic membrane)
the auditory ossicles (bones) in the middle ear
malleus, incus, stapes
middle ear is filled with air and opens into the ___, which connects it with the nasopharynx (increased likelihood for middle ear infections)
eustachian tube (help equalize pressure with atmospheric pressure)
3 regions of the labyrinth (inner ear)
vestibule, semilunar canals, cochlea
receptors in the ___ respond to changes in gravity and head position, helping maintain balance
vestibule
the cochlea contains the ____, the receptor for hearing
organ of Corti (sensory hair cells)
ringing in the ears
tinnitus
drooping of the eyelids
ptosis
involuntary eye movement
nystagmus
difficulty swallowing
dysphagia
decreased muscle tone
flaccidity
increased muscle tone
spasticity
lack of coordination or unbalanced gait
ataxia
what chart to assess distant vision with
Snellen
what chart to assess near vision with
Rosenbaum
what tests to test hearing
whisper, Rinne (place on bone then move to front of ear), Weber (on top of head and should be heard equally)
the lens becomes less elastic with aging, affecting near vision
presbyopia
eyelid muscles lose tone, causing the lower lid to turn out
ectropion
eyelid margin may turn inward causing lashes to irritate the eye
entropion
older people cannot hear ____ frequency sounds due to the degeneration in the cochlea or loss of small hairs in the ears
high
csf contains ___ mg/dL of glucose
50-70 mg/dL
inability to express or receive and understand speech as a result of brain damage
aphasia
2 categories of CVA (stroke)
ischemic and hemorrhagic
if the brain experiences ____ for more than 10min, irreversible brain damage occurs
anoxia (lack of O2 to the brain)
minimally perfused cells whose survival depends on timely return of adequate circulation
penumbra
smaller blood vessels develop to supply blood to areas with reduced blood flow
collateral circulation
cannot identify familiar objects
agnosia
in a CVA there is usually a ___ deficit
contralateral (opposite side)
weakness on one half of the body
hemiparesis
paralysis of one half of the body
hemiplegia
if Broca’s area is damaged someone may have ___
expressive aphasia
if Wernicke’s area is damaged someone may have ___
receptive aphasia
difficulty speaking caused by paralysis of the muscles that control speech
dysarthria
seeing double
diplopia
awareness of body’s position
proprioception
loss of vision in half of the eye
homonymous hemianopia
inability to carry out a familiar routine/coordinate a movement
apraxia
identifies the size and location of a CVA
CT scan
what is the earliest sign of IICP
change in LOC
what standardized chart assesses LOC
Glasgow Coma Scale
3 categories of the GCS
eye opening, verbal response, and motor response
min and max score of GCS
min 3 and max 15
when is the patient in a coma and unable to maintain their own airway on the GCS
8 (at 8 intibate)
inflammation of the eyelid, may be caused by an infection or dermatitis. Eyelid is irritated and itchy, margins are red, crusted, and scaly
blepharitis
infection of the sebaceous glands of the eyelid, usually caused by staph (red and painful)
hordeolum (stye)
painless cyst or nodule of the eyelid
chalazion
inflammation of the conjunctiva, usually caused by bacteria or virus (staph or adenovirus). Spread by direct contact
conjunctivitis (pink eye)
scratch on the cornea
corneal abrasion
what eye injury is often caused by sports
blunt eye trauma
what test can help identify the presence of foreign bodies and abrasions
fluorescein stain
nearsightedness
myopia
farsightedness
hyperopia
irregularities in the curvature of the cornea and lens. Light rays are imperfectly focused on the retina
astigmatism
clouding of the lens of the eye that impairs vision
cataract
what is a cataract that only affects a portion of the lens
immature
cataract that affects the entire lens
mature
what reflex is lost with cataracts
red reflex
how are cataracts corrected
surgery with implantation of an intraocular lens
disease characterized by increased intraocular pressure and gradual loss of vision
glaucoma
what vision is lost first in glaucoma
peripheral
what is aqueous humor produced by
ciliary body
aqueous humor drainage through the trabecular meshwork and canal of schelmm is slowed, with a gradual increase in IOP
POAG (primary open angle glaucoma)
the angle between the cornea and the iris closes, completely blocking drainage from aqueous humor from the eye, with an abrupt increase in IOP
angle-closure glaucoma
which glaucoma is a medical emergency b/c w/o prompt treatment the affected eye will become blind
angle-closure glaucoma
we want to avoid eye ___ in someone that has had episodes of angle-closure glaucoma
dilation
what is the type of medication that dilates the eye and should be AVOIDED in pts with angle-closure glaucoma
mydriatic (this has a “d” and so does “d”ilate)
what test measures IOP
tonometry (start screening at 40yrs)
what osmotic diuretic is used in ACG
mannitol
what medication constricts the pupil and is given to help open the angle in ACG
miOtic (they cOnstrict)
in glaucoma ___ and ___ are also seen in an ophthalmology exam
fundus pallor and optic disk cupping (examine through funduscopy)
name a miotic
pilocarpine
name a mdriatic
atropine
example of a carbonic anhydrase inhibitor (reduce aqueous humor production, lowing IOP)
acetazolamide
what test measures the depth of the anterior chamber and helps differentiate b/t open and closed angled glaucoma
gonioscopy
what test is used to identify if there is peripheral vision loss
visual field testing
beta blockers can also be given to decrease IOP, what vital sign will we watch to see if there was systemic effects
BP
swimmer’s ear
external otitis
when a pt presents with a foreign body such as a bean, do not do what
irrigate (may cause the object to swell)
what temp of water to use when irrigating the ear and why
body temp (too cold could induce seizure activity)
inflammation or infection of the middle ear
otitis media
the eustachian tube connects to what
nasopharynx (organisms can enter the ear through the nose and throat)
when the eustachian tube is obstructed for a long time. Air in the middle ear is gradually absorbed, causing negative pressure in the middle ear
serous otitis media
acute otitis media usually follows a ___
URI
a sensation of whirling or movement when there is none, key symptom of inner ear disorders
vertigo
anything that affects sound transmission from the external opening of the ear to the inner ear
conductive hearing loss
disorders that affect the inner ear or the auditory pathways of the brain may cause
sensorineural hearing loss
with aging, the hair cells of the cochlea degenerate, causing progressive hearing loss
presbycusis
what consonants can people suffering from hear loss not understand
t, p, or s
most common type of vascular headache (exact causes unknown)
migraine
normal IOP
15-22 (orange 10-20)
normal ICP
7-12 (orange 5-15)
a brief disruption of brain function caused by abnormal electrical activity in the nerve cells of the brain
seizure
involuntary muscle contraction and relaxation, which involves the entire body
convulsion
seizures occurring in a chronic pattern
epilepsy (seizure disorder)
a group of abnormal firing neurons that start a seizure
epileptogenic focus
what can trigger seizure activity
hypoglycemia, high fever, hypoxia
seizures are classified as ____ or ____
partial or generalized
seizures that start in one area of the cerebral cortex
partial seizures
uncontrolled jerking movements of a finger, hand, foot, leg, or the face
simple partial seizure
when a simple partial seizure spreads to other body areas and is known as ____
Jacksonian march
known as psychomotor seizures, usually begin in the temporal lobe and manifestations include automatisms
complex partial seizures
repetitive non-purposeful actions (lip smacking, aimless walking, or picking at clothing
automatisms
a warning sign that something is going to happen
aura
seizures that involve both hemispheres of the brain and result in loss of consciousness
generalized seizures
characterized by a brief change in consciousness such as a blank stare (more frequent in chlidren)
absence seizures
can develop suddenly and is the most common type of seizure with risk for potential injury
tonic-clonic seizures
what is the typical pattern for tonic-clonic seizures
aura, tonic phase, clonic phase, postictal phase
muscles are rigid with the arms and legs extended and jaw clenched. Pupils become fixed and dilated. Breathing stops and cyanosis develops
tonic contractions
movements are jerky as the muscles alternately relax and contract. The eyes roll back; tongue and cheek biting, as well as frothing from the mouth. Urinary and bowel incontinence are common
clonic contractions
post seizure the patient is unconscious for up to 30min
postictal
a continuous period of tonic-clonic seizures usually lasting 5min or more in which the patient does not regain consciousness life threatening medical emergency
status epilepticus
what test can determine the type of seizure and locate the seizure focus
EEG (electroencephalogram)
what class of drug is given to quickly stop status epilepticus
Benzodiazepines (antidote: flumazenil)
meds for seizures
clonazepam
carbamazepine (4-12)
gabapentin
phenobarbital (15-40)
phenytoin (10-20)
valproic acid
a flexion posturing
decorticate (into the core)
an extension posturing
decerebrate
rescue med for migraines
ketorolac
form of vascular headache that typically begins 2 to 3 hours after the person falls asleep. Usually the same side of the head is involved each time
cluster headache
headache that often results from prolonged muscle contraction of the head and neck, due to abnormal posture (viselike feeling)
tension headache
a slow progressive neurodegenerative movement disorder, resulting from a loss of dopamine
Parkinson disease (PD)
an inhibitory neurotransmitter
dopamine
an excitatory neurotransmitter
acetylcholine
3 cardinal signs of PD
tremor, rigidity, bradykinesia
slowed voluntary movements and speech
bradykinesia
the classic tremor in PD that occurs with the thumb and fingers
pill rolling
muscle rigidity makes active and passive movement difficult, the extremity may move but it does so in a jerky movement called ____
cogwheel rigidity
a ___ scan may show decreased levels of levodopa (precursor to dopamine)
PET
most common procedure for PD
deep brain stimulation (DBS)
two other procedures done in PD that destroy certain areas in the brain to decrease tremors
thalamotomy and pallidotomy
progressive, inherited neurologic disease and involves a lack of neurotransmitter GABA (which causes acetylcholine lvls to drop and dopamine lvls to rise)
Huntington disease (HD)
what 3 things does HD affects
personality, intellectual function, and movement
constant, jerky, uncontrolled movements of the body that is a characteristic manifestation of HD
chorea
death from HD is usually due to what
aspiration pneumonia
an acute, progressive inflammation of the peripheral nervous system and often follows a recent viral or bacterial infection
guillain-barre syndrome (GBS)
where do the manifestations of GBS
in the lower extremities
what are the cataracts that occur from aging
senile cataracts
Sense of smell
I, olfactory
Vision
II, optic
Eye movements
Extraocular muscles
Pupillary control (pupillary constriction)
III, oculomotor
Down and inward movement of eye
IV, trochlear
Sensations of face, scalp, and teeth
Chewing movements
V, trigeminal
Outward movement of eye
VI, abducens
Sense of taste on anterior two-thirds of tongue
Contraction of muscles of facial expression
VII, facial
Hearing
Sense of balance (equilibrium)
VIII, vestibulocochlear
Sensations of throat, taste, swallowing movements, gag reflex
Sense of taste on posterior one third of tongue
Secretion of saliva
IX, glossopharyngeal
Sensations of throat, larynx, and thoracic and abdominal organs
Swallowing
Voice production
Slowing of heartbeat
Acceleration of peristalsis
X, vagus
Shoulder movements (trapezius muscle)
Turning movements of head (sternocleidomastoid muscles)
XI, accessory
Tongue movements
XII, hypoglossal
