Nervous system Flashcards
(114 cards)
overall functions of the NS
NS
to transmit info rapidly
to gather input and respond accordingly
3 main functions of the 5 main parts of the nervous system
NS
Sensory input - sensory receptor, sensory neurons
integration - CNS including interneurons
motor output - efferent/motor neurons, effector cells (muscle cells)
describe sensory input, integration, motoar output
NS
input - detection of stimulus
integration - processing in brain
output - response in another bodypart
CNS vs PNS
NS
CNS - Brain, spinal cord
PNS - efferent, afferent neurons, all other neurons not in CNS
what are the subdivisions of the PNS
NS
Sensory division - sensing external, sensing internal
Motor division -autonomic (parasympahteic, sympathetic) , somatic
Atonomic vs somatic in PNS
NS
Autonomic - involulntary reactions,signals to smooth msucle, cardiac muscle
somatic - voluntary reactions, signals go to skeletal muscle
sympathetic vs parasympathetic
NS
symp - arousal and eng gen, increase stress response, inhibit digest
parasymp - calming, decrease heart, stimulate digestive
types of senses
external: somatic(skin, muscle, joints), special(vision, hearing, equilibrium)
internal: visceral(fullness of stomach, blood pressure)
NS
Types of sensory receptors by location
NS
Exteroreceptors - detect stimuli from outside
interoreceptors - detect stimuli from inside body (viscerla senses)
Types of sensory receptors by stimulus
5
NS
mechanoreceptor - pressure (in skin, stomach, bladder)
photo - light (eyes)
chemoreceptor - chemcials (nose, mout, brain, arteries)
thermo- temp(skin, organs)
nociceptor - pain (skin, organs, glands, vessels)
NS
what are the 5 components of neuron also funct
dendrites - gets input from other neurons
cell body - does metabolism, protein syth
axon hillock - where action potential starts
axon-sends info
synaptic terminal - contains/releases neurotransl
WHat is neuron
describe
NS
Structural and functional unit of nervous system
are excitable - can make large changes in membrane pot(electrical signals)
do not do cell division when mature
nerve cell = neuron
What are the types of neyrons
NS
sensory
interneuron(CNS)
motor neurons(stereotypical neuron)
What do sensory neurons do
NS
Afferent neurons
carries signals from sense recept to CNS
What do interneurons do
NS
association neurons
get signals from sensory neurons
deliver signals to outgoing neurons
can be excitatory or inhibitory
What do motor neurons do
NS
efferent neurons
carries signals out of CNS to effetor cells
What are supporting cells/ glial cells
3 types
90% of cells in nervous system
structural and metabolic support
astrocytes(CNS)
oligodendrocytes(CNS)
schwann cells (PNS)
What is blood brain barrier
and astrocyte use
NS
blood vessels completly sealed off by astrocytes- no electrical conduction
stop things from contaminating brain
uses active transport proteins instea of hole
Wha do schwann cells and oligodendrocytes do
wrap around axon
provide insulation for electrical impulses
layer cllaed myelin sheath
schwann is PNS
oligodendrocyte is CNS
Purpose of myelin sheath
NS
provide electricla insulation
makes impulse travel faster
like insulation around wires
has nodes of ranvier
Types of nerve ciruits
NS
Divergent
convergent
circular
describe divergent nerve circuit
NS
nerve impulse in one presynaptic neuron
nerve impulses in several prostsynaptic neurons
ex photoreceptors to many parts of brain
Describe convergent nerve circuit
NS
nerve impulse from many presysnaptic neurons
nerve impulse in one postsynaptic neuron