nervous system Flashcards
what is the white matter on a spinal cord diagram?
fat
what is the grey matter on a spinal cord diagram?
neurons
why do children lack motor skills?
their myelin in still immature
what is multiple sclerosis? what are the symptoms?
- a disease that attacks myelin
- symptoms: fatigue, no coordination, impaired sensation
what is the function of the premotor cortex?
- controls advanced movements
- sport/high skill area
- 6th sense
what is the 10 000 hour principal?
10 years, 10 000 hours is how long it takes to be an elite athlete
what is the cerebellum?
- compares information from effector impulses (what’s been done) and sensory receptors (how it was done)
- makes revised impulses (correction factor) from the cerebral cortex
what is the cerebral cortex?
where original effector impulse was initiated
what is the reflex arc? what are the 4 steps?
- involuntary muscle contraction
step 1: receptors puck up stimuli
step 2: sensory/afferent neurons conduct impulse to spinal corn
step 3: association/interneurons process information, execute a response, and send an efferent impulse
step 4: motor/efferent neurons conduct efferent impulse to effectors/muscles
what is the sensory area?
- where sensory impulses terminate
- sensation occurs when impulses reach here
what is the motor area?
- where efferent impulses originate
- the start of motions
- actions can’t be done when these areas are damaged
what is the cerebrum?
- outside portion of cerebral cortex
- largest part of the brain
what does “neur-“ mean?
nervous system
what does it mean when a muscle is innervated?
a muscle is stimulated
nerves ____, muscles ____.
nerves conducts, muscles contract
what is anaerobic glycolysis? (requires and produces)
- requires CHO
- produces lactic acid and ATP energy
what is aerobic glycolysis? (requires and produces)
- requires protein, fat, CHO, and O2
- produces CO2, H2O, ATP
what is mitochondria’s fuel?
free fatty acids
what are the structures of a neuron?
- dendrites
- cell body
- axon
- myelin
- nodes of ranvier
- schwann cell
what is an axon?
- long fibre
- conductor
- covered to protect it from damage
what is myelin?
- covering on axon
- fat deposits insulate
what are the nodes of ranvier?
gap between schwann cells
what are schwann cells?
allows conduction to jump from node to node
what is a nerve synapse?
gap between neurons
what is a neuromuscular junction?
- also called myoneuron junction
- gap between terminal (last) neuron and muscle
what is muscle recruit?
the determining of which muscles to innervate in order to do a movement
how do we increase muscular force?
by increasing the number of fibres used
what are the 2 systems within the nervous system?
- central nervous system
2. peripheral nervous system
what is the central nervous system?
- in charge of everything, the highest centre
- consists of the brain and spinal cord
what is the peripheral nervous system?
- consists of sensory/afferent and motor/efferent nerves
- sensory nerves receive stimuli and send it the CNS for processing
what systems do the motor/efferent nerves control?
autonomic and somatic nervous system
what is the autonomic nervous system?
- controls vital organs and involuntary muscle
- keeps the body in balance
what is the somatic nervous system?
controls skeletal and voluntary muscle
what systems do the autonomic nervous system control?
sympathetic and parasympathetic system
what is the sympathetic system?
speeds up body functions
example) speeds up heart rate, cocaine
what is the parasympathetic system?
slows down/inhibits body functions
example) fentanyl
what is a proprioreceptor?
picks up specialized movement stimuli
what is kinesthesia?
- the feeling of movement
- how something feels good/bad and how positioning feels good/bad
what are the 3 proprioreceptors?
- muscle spindle (in muscles)
- golgi tendon organ (in tendon)
- pacinian corpyscle (in joints)
what is a muscle spindle?
- along the side of muscle fibres
- causes contraction when muscle stretches too fast/much
- has a fascilitory response: a response to an incorrect movement
what is a golgi tendon organ?
- picks up tension stimuli
- relaxes/inhibits to allow continuation of passive stretching
what is proprioneuro fascilitory?
- stretching after surgery to gain more stretch
- isometric contraction > relax > further stretch
what is acetyl choline?
- conducts impulse to the end of it’s destination (the muscle)
- when impulse reaches synapse, ACH is released to bring impulse to postsynaptic neuron
what are the 3 states of neurons/muscles?
- polarization
- depolarization
- repolarization
what is polarization?
- muscle at rest
- positive and negative ions are inside and outside neurolemma, more positive charges outside
- nothing happens because of the location of Na+ and K+
- at resting potential
what is resting potential?
-85mV
what is the neurolemma?
cell membrane of neuron
what is depolarization?
- cell membrane is permeable to Na+, allowing Na+ to enter cell and K+ goes outside
- cell inside is positive, outside is negative
- at action potential
what is action potential?
-70mV
sudden change in electrical activity across nerve/muscle membrane due to a rapid flow of Na+ across cell membrane into cell, releasing acetyl choline
what is repolarization?
- Na+ goes back outside cell via Na+ pump
- K+ goes back inside of cell
- preparation for the next impulse/contraction
how does the muscle reach action potential?
- muscle receives excitability and inhibitory stimuli at the same time
- excitability > inhibitory to reach action potential
