Neurological System Overview Flashcards
what are the two major parts of the neurological system?
CNS & peripheral NS
what is a function of the nervous system?
controls the motor, sensory, autonomic, cognitive, & behavioral activity
what is the brain made up of?
neurons & spinal cord
list some functions of the brain (6)
- contains over 100 billion cells that monitor all of the above along w internal & external environment & helps to maintain homeostasis
- works very closely w the endocrine system
- cells link motor & sensory pathways
- responds to internal / external environments
- maintains homeostasis
- directs all psychological, biologic, & physical activity through complex chemical & electrical messages
what are neurons? what 3 things do they contain?
cells of the NS (primary functioning unit) contain dendrites, axon, & nerve cell bodies
dendrites
receive electrochemical messages from the previous neuron
axon
carries impulses away from cells; long part of the nerve; if damaged in anyway, the impulse will not be carried properly & the wires will short out
nerve cell bodies
ganglia; helps w transmission of messages
acetylcholine
- part of SNS or PNS?
- function
part of the parasympathetic nervous system; usually excitatory; may be inhibitory (heart vagal nerve)
serotonin
- SNS or PNS?
- function
Inhibitory; controls mood / sleep, inhibits pain (lots to do w depression)
dopamine
- SNS or PNS?
- function
- which type of patients lack dopamine?
inhibitory; affects behavior (attention, emotion) fine motor movement; parkinson’s disease patients often lack dopamine
norepinephrine
- SNS or PNS?
- function
excitatory; affects mood & overall activity; fight or flight
gamma-aminobutyric acid
- SNS or PNS?
- function
inhibitory; calms nerves down; often used in patients w seizures or neuropathy pain (gaba pentin) decreases stimulation of nerve
enkephalin / endorphin
- SNS or PNS?
- function
excitatory; pleasurable sensation; inhibits pain transmission; released a lot when exercising
which two neurotransmitters must have a good relationship?
acetylcholine & dopamine!
the brain accounts for approximately ____ of total body weight
2%
3 major areas of the brain & their main functions
- Cerebrum: deals w cognition, concentration, abstract thinking, motor function, speech, judgment, & personality
- brain stem: Center for auditory & visual reflexes; Reflex centers for respiration, BP, HR, coughing, vomiting, swallowing, & sneezing are also located in the medulla
- Cerebellum: integrates sensory info to provide smooth coordinated movement; Controls fine movement, balance, & position (postural) sense of proprioception (awareness of position of extremities w out looking at them)
corpus callosum
connects the two hemispheres of the cerebrum; transmits info across the two hemispheres
3 parts of the cerebrum & their functions
- Thalamus: relay station for senses except smell (memory, sensation, & pain impulses); relays
messages from one area of the brain to the next - Hypothalamus: relay station for all hormones
Important in the endocrine system
Works w the pituitary
Temp regulation
Hunger center / appetite control
Sleep-wake cycle, BP, aggressive & sexual behavior, emotion responses (blushing, rage, depression, panic, & fear); Controls / regulates ANS - Basal ganglia: responsible for control of fine motor movements, including those of the hands & lower extremities
list & describe the 4 lobes of the basal ganglia
- frontal: largest lobe; front of the brain (concentration, abstract thought, info storage / memory, & motor function) responsible for person’s affect, judgment, personality, & inhibitions
parietal: analyzes sensory info & relays the interpreted info to the cortex. Essential to person’s awareness of body position in space, size, shape, & right-let orientation
Temporal: contains the auditory receptive areas; plays role in memory of sound & understanding of language & music
Occipital: responsible for visual interpretation & memory
which lobe of the basal ganglia is the Broca’s speech area part of? which hemisphere of the brain is it in?
frontal lobe; left hemisphere
if a patient has a left hemispheric stroke, which side of the body will it affect?
right!
the spinal cord has ascending & descending pathways - what is the difference?
ascending: carries signals from the periphery to the brain
descending: carries signals from the brain to the periphery
list the 4 segments of the spinal cord
- cervical
- thoracic
- lumbar
- sacral (posterior leg, cervical vertebrae)
if there is a fracture in C1 or C2 area of the brain, why is this extra serious?
they are typically deadly!
how does the cranium protect the brain? how many bones does it have?
protects the brain from swelling when injured; has 8 bones
what does the vertebral column protect? how many vertebrae does it contain?
protects the spinal cord; has 33 vertebrae
what is the role of the meninges? how many layers does it have? (list & briefly describe them)
anchor the spinal cord & brain together
3 layers:
1. dura mater: outermost layer; tough & thick layer (epiDURAL)
- Arachnoid (spider webs): middle layer; cerebral spinal fluid being made & stored in the subarachnoid space & coats the surface of the brain
- Pia mater: innermost layer that hugs the brain
cerebral spinal fluid (CSF)
- what is it?
- how much is produced per day?
- important function?
- what does it contain?
- clear, colorless fluid produced in the ventricles
- produce about 500 ml per day
- important in immune & metabolic functions in the brain
- contains protein, glucose, & electrolytes
which ventricle drains CSF & where does it drain it to?
4th ventricle drains this fluid into the subarachnoid space on the surface of the brain & spinal cord
what should the CSF NOT contain?
RBC & minimal WBC
if sugar is found in nasal drainage, what does this indicate?
a CSF leak!
how do arteries & veins protect the brain?
provide nutrients & O2 to brain tissue (remains constant) - if not enough, there will be confusion in patients
what percentage of CO goes to the brain?
15%-20%
circle of willis
collateral circulation in the brain; if blocked, then brain tissue will die (strokes, aneurysms, & clots often occur in the bifurcation along the circle of willis)
how many layers do blood vessels in the brain have?
2
how many layers do arteries in the brain have? this makes arteries more susceptible to ___
3; rupture
veins in the brain have no ___
valves
blood brain barrier
- what is it?
- what is it formed by?
- what does it prevent?
protective function formed by epithelial cells of the brain’s capillaries & prevents certain drugs from crossing into the brain tissue
what types of drugs can cross the blood brain barrier?
lipophilic (fat-soluble) drugs
what types of drugs can not cross the blood brain barrier?
hydrophilic (water-soluble) drugs
resting potential in spinal cord
nerve impulses get prepared to fire
nerve impulses in spinal cord
message is carried down nerve cell
myelin in spinal cord
coding that helps carry nerve impulse
receptors in spinal cord
- where are they located?
- what is their function?
located on the dendrites; pick up the neurotransmitters that are in the synapse
in the peripheral & autonomic NS, impulses are carried along ___
axon
how many cranial nerves are there?
12
how many pairs of spinal nerves are there?
- list them
31 pairs
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
sympathetic NS
- function
- what is the main neurotransmitter?
- “fight or flight”
- norepinephrine is the main neurotransmitter
parasympathetic NS
- function
- what is the main neurotransmitter?
- “rest & digest”
- acetylcholine is the main neurotransmitter
olfactory cranial nerve
- number
- S or M?
- function
I ; sensory only ; olfaction (smell)
optic cranial nerve
- number
- S or M?
- function
II; sensory only; vision
oculomotor cranial nerve
- number
- S or M?
- function
III; sensory & motor; extraocular eye movement (PERRLA)
trochlear cranial nerve
- number
- S or M?
- function
IV; sensory & motor; serves the superior oblique eye muscle (up & down eyeball movement)
trigeminal cranial nerve
- number
- S or M?
- function
V; sensory & motor; sensory from face & mouth (brush cotton ball across cheek), motor to muscles of mastication (jaw movement)
abducens cranial nerve
- number
- S or M?
- function
VI; sensory & motor; lateral eye movement
facial cranial nerve
- number
- S or M?
- function
VII; sensory & motor; serves the muscles of facial expression (raise of eyebrows & puff out cheeks) & taste on tip of tongue
vestibulocochlear or auditory cranial nerve
- number
- S or M?
- function
VIII; sensory; equilibrium & hearing (whisper test)
Glossopharyngeal cranial nerve
- number
- S or M?
- function
IX; sensory & motor; gag reflex / swallowing & ability to taste on the back of tongue
Vagus cranial nerve
- number
- S or M?
- function
X; sensory & motor; vibrations from pharynx (voice box) & swallowing & speaking
Accessory cranial nerve
- number
- S or M?
- function
XI; sensory & motor; serves muscles that move head, neck, & shoulders
Hypoglossal cranial nerve
- number
- S or M?
- function
XII; sensory & motor; positioning & moving of the tongue
which group of meds can cause muscle weakness?
statins!
which vitamins are vital to the neuro system? lack of ___ & ___ can cause seizures or muscles weakness
B vitamins; lack of Mg & Ca
when examining reflexes, which type are abnormal?
pathologic
list the 6 types of deep tendon reflexes
- Biceps
- triceps
- Brachioraldialis
- patellar
- achilles
- clonus
clonus reflex
hyperactive dorsiflexion (jerking) - when tapping knee w hammer in particular spot, foot jumps up
what are the 3 superficial reflexes (cutaneous) - can touch the skin & may withdrawal from you
- corneal
- gag
- upper / lower abdominal
list the 4 pathologic reflexes
- Babinski’s
- snout
- suck or rooting
- Grasp
Babinski’s reflex
- describe
- indicate of?
Abnormal is dorsiflexion of the toes (fanning) when something is rubbed against bottom of foot
indicative of upper motor neuron lesion
normal in a baby but not in an adult
snout reflex
- describe
- indicative of?
pursing lips when touched; normal in a baby but not in an adult
indicative of progressive nerve degeneration
suck or rooting reflex
- describe
- indicative of?
lips will be touched & patient will immediately try to suck
normal in a baby but not in an adult
indicates progressive nerve degeneration
grasp reflex
- describe
- indicative of?
touching palm of hand & trying to close hand around you
indicative of progressive nerve degeneration
CT scan
- used w or w out contrast?
- pre procedure responsibilities
- post procedure responsibilties
- if patient has mental status changes or possible CVA, will use w out contrast first!
- pre procedure responsibilities: always find out which type of stroke it is before giving a CT w contrast; assess allergies
& kidney function - post procedure responsibilities: increase fluids to flush contrast out
which procedure is usually done after a CT scan if answer was not found?
MRI
MRI
- pre procedure responsibilities
- Ask if pregnant, have any metal in body or a pacemaker, or work as a mechanic (checklist on sheet of paper to fill out before patient can be sent to MRI)
- Remove any medication packages that have a foil backing on them!
purpose of an MRA
visualizes the cerebral vasculature (looks at blood vessels feeding the brain)
PET scan
- purpose
- computer-based nuclear imaging; will detect if there is a decrease in blood flow due to lack of sugar in the brain or due to metabolic changes
- can see tumors, aneurysm, or blood clots
brain requires ___ of our body’s blood glucose to function properly
80%
SPECT
- purpose
three-dimensional imaging technique; assesses perfusion of the brain; detects how far a stroke has extended in the brain
Myelography
- purpose
- often done on which patients?
x-ray of the spinal subarachnoid space after contrast is injected into that
- Looks for any changes in the spinal cord, disk, or vertebrae
- Often done for patients who are having lots & lots of back pain
transcranial doppler
- purpose
ultrasound of the brain; goes across the cranium; records blood flow velocities of intracranial arteries
- Looks for any signs of stroke, bleeding, tumors
cerebral angiography
- purpose
contrast media is injected into the arteries of the brain to look for any type of clots & assess blood flow to the brain
electroencephalogram (EEG)
- purpose
- used in which patients?
- nursing implications
- purpose: assesses the electrical activity in the brain; detects seizures or if someone is brain dead
- Used in patients that have seizures or are suspected of having seizures
- patient will have numerous electrodes placed on their head
- nursing implications: sleep deprivation, withhold anticonvulsants, tranquilizers, stimulants, & depressants 24-48 hours before; omit coffee, tea, cola, chocolate but MAY have a meal
electromyography (EMG)
- purpose
assesses the nerve innervation to the muscle (see if the muscle is responding to the impulses sent to it by the nerves)
nerve conduction
- purpose
can see if impulses are getting through the nerves
lumbar puncture
- purpose
- nursing implications
- assesses for any infection in the brain (meningitis or herpes encephalitis) that may be causing swelling; admin of medications (epidural in pregnant women)
- nursing implications:
- Be sure patient is lying on side curled up in fetal position
- Make sure they lay still as this procedure goes into the epidural space to withdrawal cerebral spinal fluid
- CSF is sent off to lab to test for glucose, red cells, white cells, & other electrolytes
*see lumbar puncture procedure document on canvas
list some complications of a lumbar puncture (8)
- post-lumbar H/A (place patient flat in bed; remain for 24 hours in order to hold spinal fluid)
- herniation of the brain
- abscess
- hematoma
- *meningitis
- difficulty voiding
- elevated temp
- backache / spasms, stiff neck
muscle biopsy
- purpose
piece of muscle is taken to assess a patient’s weakness and see if it’s either the muscle or nerve causing the problem
list some structural & physiologic changes in the geriatric population (4)
- Decrease in brain size (1,400 grams to 1,200 grams)
- Decreased cerebral blood flow & metabolism
- Visual & auditory changes (especially at night)
- Sleep disturbances (less stage 4 sleep)
list some motor alterations in the geriatric population (8)
- Decreased muscle mass
- Decreased motor alertness = response time is slower
- Atrophy
- Loss of myelin sheath
- Deep tendon reflexes decline
- Pupils begin to change
- Decrease in neurons = fewer synapses resulting in decreased response time
- Issues w spinal column
- Kyphosis: hump back
- Scoliosis
list some sensory alterations in the geriatric population (5)
- Decrease in temperature regulation & pain perception
- Increased risk for delirium - mental status changes are not a normal part of aging though!
- Depression is often misdiagnosed!
- Decrease in hearing, taste, & smell
- Decreased tactile sensation (patients can get burns on them from heating pads due to this decreased sensation)
