nervous system and the five senses Flashcards
what are the two branches of nervous system?
Central nervous system and peripheral nervous system
what is the function of CNS?
to integrate and respond to signals from PNS
what are the two components of CNS?
Brain and spinal cord
what is the function of PNS?
keep in touch with outside environment and respond to it
what is PNS comprised of?
nerves outside of brain and spinal cord; motor and sensory neurons
what is the autonomic nervous system?
part of PNS; responds to stimuli over which we dont have control over.
what are the two branches of autonomic
sympathetic and parasympathetic
what is sympathetic branch?
fight or flight response; response to perceived threats
what does the sympathetic branch secrete
adrenaline(epinephrine)
what is a neuron(neurone)
a specialized nerve cell;
- it doesnt undergo mitosis after birth, cannot be replaced
- conducts action potentials
what are action potentials
change in electrical potential with passage of an impulse along the membrane of a muscle cell or nerve cell
what is synapse
small gap b/w ends of nerves
how do nerve impulses continue when it reaches a synapse?
neurotransmitters
what are neurotransmitters
they transmit nerve impulses across synapses
what are an example of the 5 neurotransmitters
acetylcholine serotonin dopamine adrenaline endorphins
when does the impulse for release of neurotransmitters occur?
at the axon end
4 stages of action potentials?
- resting potential
- depolarization
- repolarization
- resting potential
what is a nerve?
is a cord made up of bundles of axons, it comprises white matter
what is white matter
nerve cords
what is grey matter
bodies of nerve cells
where is grey matter mainly found?
in the brain and spinal cord, but also in ganglia and some organs.
what is somatic nervous system branch?
controls voluntary movements
motor neurons
CNS to muscles and glands
sensory neurons
sensory organs to CNS