Nervous System Flashcards
CNS
Brain analyzes, interprets and stores info
Types of receptors
chemoreceptors
thermoreceptors
baroreceptors
proprioceptors
chemoreceptors
detects changes in chemicals such as CO2 or calcium
thermoreceptors
send changes in temperature
baroreceptors
walls of arteries to detect changes in BP
proprioceptors
in muscles to detect changes in body position
2 systems of the PNS
Somatic and autonomic
somatic system
regulates voluntary movement after feedback from senses
autonomic system
involuntary regulation of internal systems
2 parts of autonomic system
sympathetic and parasympathetic
sympathetic nervous system
accelerates systems- fight or flight
parasympathetic
pumps the breaks
2 types of neurons
affrent and effrent
affrent neurons
carry messages to CNS
long dendrite, short axon
effrent neurons
motor commands from CNS to target
dendrites
receive messages then send to cell body
axon
extends from cell body
carry info from cell body ot axon terminal
nucleus
DNA of cell
node of ranvier
allows nutrients and waste to enter/leave cell
synapses
gaps between neurons and muscle cells that neurotransmitters neither excite or inhibit
2 neurotransmitters that activate synapse
acetylcholine (muscle contraction)
norepinephrine (adrenaline)
neuron membrane
negatively charged inside (action potential)
impulse causes sodium ions to penetrate enuron
action potential becomes positively charged and is allowed to move
potassium ions restore balance
motor unit
smallest unit of contraction, recruited in an all or none principal
fewer fibers in motor unit =
more precise movement
force is determined by
number of fibers in a motor unit. smaller units are recruited first
stretch reflex
prevents overstretching through golgi tendon organ reflex
golgi tendon orgon reflex
golgi organs detect degree of force exerted against tendon by a contracting muscle, if the force is too much, golgi organs fire off inhibitory signals to CNS
reciprocal inhibition stretching
stretch is more effective if muscle is already relaxed, done with a partner
plyometrics
concentric muscle contraction is stronger if immediately follows eccentric contraction of same muscle
rapid deceleration of body followed by rapid acceleration in opposite direction
3 phases of plyometrics
pre-stretch, amortization, muscle contraction
