nervous system Flashcards
nervous system stages
sensory input
integration
motor output
sensors
detect external stimuli and internal conditions and transmit information along sensory neurons
integration
sensory info is sent to the brain or ganglia where internuerons integrate the info
motor output
leaves brain or ganglia via motor neurons which trigger activity
axon hillock
axon joins the cell body
synapse
juction between axon and another cell
presynaptic cell
neuron
postsynaptic cell
nueron, muscle or gland cell
glia
nourish or insulate neurons
resting potential
K greater inside
sodium potassium pump use energy of ATP to maintain K and Na gradient
depolorization
Na channels open, allowing Na into the cell
action potential
resting threshold peak decline refactory period
electrical synapses
electrical current flows from one neuron to another
chemical synapses
chemical neurotransmitter carries info across the gap junction
synaptic vesicles
presynaptic nueron synthesizes and packages the nuerotransmitter here
synaptic cleft
where it diffuses, received by post synaptic cell
system structure
consists of
circuits of neurons and supporting cells
increased cephilization over evolutionary time
CNS
brain and spinal cord
responsible for integration or sensory and motor signals
PNS
sensory and motor nerves
fight or flight, rest and digest
reflex arc
integration of sensory info occurs in the spinal chord without brain involvement
gray matter
nueron cell bodies, dendrites unmyelinated axons
white matter
bundled axons with myelin sheaths
ventricles
shares cerebral spinal fluid with spinal cord
