week 7 path Flashcards
what are the two smaller systems that make up the nervous system
the CNS and the PNS (peripheral nervous system
what constitutes the CNS
CNS consists of the brain, spinal chord, and cranial nerves 1 and 2
what constitutes the PNS
cranial nerves 3-12, spinal nerves and the autonomic nervous system
what are the three main characteristics of neurons
excitability (ability to start an impulse)
conductivity (conduct nerve impulses from one neuron’s to the next)
ability to influence and communicate with other cells
what is the myelin sheath
an insulated layer that forms around neurons and allows impulses to smoothly travel across
what is an action potential
basically the action of the neuron initiating, receiving and processing a message. it is defined as a rapid, self-propagating and transient change in voltage across the cell membrane
how does sodium and potassium move around to cause an action potential
sodium comes in and potassium leaves
what is the synapse
basically the bridge between two neurons. this is where near transmitters are released to continue the message further (the space between two neurons)
what type of movement happens when an action potential reaches a gland vs. muscle
a gland is involuntary, a muscle is voluntary
how does a signal transmit across the synapse
the action potential starts at the presynaptic terminal of the first neuron.
it then gets to the synaptic cleft and acetylcholine is released.
there are receptors on the post synaptic cleft (second neuron) that receive acetylcholine.
what does a neurotransmitter do
its a chemical substance that travels actoss the synapse to signal the action potential to continue into the other neuron.
they can be excitatory or inhibitory
whats the difference between excitatory and inhibitory neurotransmitters
excitatory causes an influx of sodium which promotes an action potential.
inhibitory causes efflux of potassium, which prevents the firing of the action potential.
what does the GABA neurotransmitter do (what kinds of things does it regulate)
its inhibitory, contributes to motor control, vision and regulates anxiety
what does dopamine (neurotransmitter) do
controls movement and posture, regulates mood
what does acetylcholine (neurotransmitter) do
excitatory nt that triggers muscle contraction and stimulates the secretion of hormones. affects alertness, anger, focus, aggression, sexuality and thirst.
(the “go” neurotransmitter)
what does norepinephrine do
a nt that is important for attentiveness, sleeping, dreaming, and learning. Also released as a hormone and affects blood vessel constriction and increased heart rate
whats the difference between epinephrine and norepinephrine
what does serotonin do
regulates body temperature, sleep, mood, appetite, and pain.
describe the neuromuscular motor pathway
motor cortex, spinal cord, peripheral nerves, neuromuscular junction, muscle fibre.
when in the motor pathway do upper motor neurons switch to lower motor neurons
when it gets to the peripheral nerves
how does a signal generate from brain to muscle fibre
the motor pathway lol
which area of the brain is responsible for movement (captain of the ship)
the motor cortex
which two parts of the brain help the motor cortex
basal ganglia and cerebellum
which part of the brain initiates and regulates body movements
the basal ganglia
which part of the brain regulates details of motor control, balance, smoothness, and coordination
cerebellum
which part of the brain is affected with Parkinson’s
basal ganglia because its initiates all body movements
what is the analogy we use for the spinal chord
a massive information highway between the brain and the rest of the body
whats the difference between the ascending and descending pathway
ascending pathway: signals to brain
descending: signals to muscles
what are afferent vs efferent nerves
afferent: sensory spinal nerves
efferent: motor spinal nerves
what is the purpose of spinal/peripheral nerves
allow brain to stay connected to peripheral parts of the body, banishes out to muscles and organs all over the body. this is how the body reacts to environmental stimuli
whats the difference between pyramidal and extrapyramidal neurons
pyramidal: efferent neurons carry impulses for voluntary muscle movements, whereas extrapyramidal: efferent neurons that carry impulses for involuntary movement
what happens at the neuromuscular junction
neurotransmitter are released on to the muscle fibre to trigger a nerve impulse/muscle contraciton
what is the path behind MS
it is a chronic, inflammatory autoimmune disorder. it damages the myelin sheath. this affects the neurons of the brain, spinal cord, and optic nerve.
how does MS cause sensory, motor and cognitive deficits
impulses are disrupted from scarring in demyelination that blocks movement of signals
what are the risk factors of MS
females, being on colder climates (associated with a vitamin D deficiency), being 30 (average age of onset), and it can be inherited genetically
what are some precipitating factors that can lead to exacerbation of MS
infection, trauma, pregnancy, stress, fatigue, poor health, recent surgery
how can you determine the clinical manifestations of MS
it depends on where the damage to the myelin sheath is and how quickly individuals start treatment
what are the overall symptoms of MS
general weakness, limb paralysis, slowed speech and chewing.
what type of disorder is MS
autoimmune, chronic, and inflammatory
what are some serious complications of MS and why do they occur
Paralysis can lead to bedsores. Bladder problems may cause repeated urinary tract infections. Inactivity can result in weakness, poor posture muscle imbalances, decreased bone density, and breathing problems.
what type of disease is Parkinson’s
it is a progressive neurodegenerative disease of the CNS
what are the risk factors for developing Parkinson’s disease
more common in men
60 is the average age of diagnosis
antipsychotic meds
illicit drug use
dementia
exposure to chemicals
what is the patho behind Parkinson’s
dopamine producing neuron’s in ten substantia nigra are destroyed. dopamine is the inhibitory neurotransmitter which means less inhibition of overall muscle movement
list 3 classic clinical manifestations of PD
tremor (from too much acetylcholine)
rigidity (from increased resistance to passive motion)
bradykinesia (loss of automatic movements, slowness of movement)
which motor system is affected with Parkinson’s disease
the extrapyramidal motor function.
how does Parkinson’s disease affect the brain and movement
the brain needs a good balance of acetylcholine and dopamine to produce proper motor function. If dopamine is lost, there is no inhibition of motor function.
which areas of the brain are effected with PD
the substantia nigra and midbrain
what are the 5 stages of Parkinson’s
- initial stage (unilateral limb movement, minimal weakness, hand trembling)
- midstage (bilateral limb involvement, mask like face, slow shuffling gait)
- moderate stage (postural instability, increased gait disturbances)
- severe disability (akinesia, rigidity)
- complete ADL dependence
what are the 6 complications of neuromuscular disorders
aspiration, pneumonia, UTI, pressure sores, malnourishment, falls
what are dermatones
area of the skin innervated by sensory fibres of a dorsal route (sensory nerves)
what are myotomes
muscle group innervated by motor neurons of a ventral route (movement)
muscle equivaent of a dermatome
what are the functions of the vertebral column
protects the spinal cord,
supports head, provides flexibility
what is the order of the vertebrae from top to bottom
7cervical
12thoracic
5lumbar
5sacral
4coccygeal
where are the cervical vertebrae located
in the neck
where are the thoracic vertebrae located
upper back
where are the lumbar vertebrae located
lower back
where are the sacral and coccyx vertebrae located
bum (coccyx is the tailbone area)
how would you classify a spinal cord injury
- mechanism of injury
- level of injury
- deficity
- completeness/degree
where is the vertebral damage causing tetraplegia
C8 and above
where is the damage causing paraplegia
T1-T6
which vertebrae damage causes total loss of respiratory function
above C4
which vertebrae landmark causes CV changes like bradycardia and hypotension
above T6
if the injury is in C4 where would it be located on the body
middle of the neck
if the injury is in T6 where would it be located on the body
upper back
what is the skeletal level of spinal cord injury
what is peripheral neuropathy
damage through destruction/inflammation to peripheral nerves
- causes abnormal processing of sensory input
whats the difference between mononeuropathy and polyneuropathy
mono: damage to a single nerve, poly: systemic/multiple nerves
what are some common causes for peripheral neuropathy
diabetes, hypothyroidism, vitamin deficiencies, MS, Lyme disease, shingles.
what are some life threatening causes of peripheral neuropathy
gillian barret: viral infection that begins in peripheral nerves
botulism: neurotoxin exposure
tetanus: neurotoxin exposure
what are some autonomic clinical manifestations
bowel, bladder, and digestive dysfunction
heat intolerance
hypotension
