central nervous system and neurotransmitters Flashcards
what is the role of the nervous system
monitors and coordinates internal organ function and responds to changes in the environment
what are the 2 main organs of the CNS
brain
spinal cord
where does the spinal cord receive information from
skin, joints and muscles
where does the brain receive information directly from
sensory organs
what is the role of neurons
transports information across the body
what are 3 parts to a neuron
soma (cell body)
denarites
axon
describe the soma
the body of a neuron and contains the nucleus
describe the denetrites
short, bushy-like
receives information
describe the axon
transmits information
where action potential happens
what covers the axon
mielyon sheet
what is the purpose of the mielyon sheet
speeds up messages
what happens if a neurotransmitter isn’t accepted into the next neuron
re-uptake back into the synapse
how many neurotransmitters do we have
over 100 different kinds
define neuron
a type of cell that receives and sends messages to the brain to the body
describe how neurotransmitters are diffused between neurons
the action potential triggers the release of the synaptic vesicle of the pre-synaptic neuron
neurotransmitters diffuse across the synapse and bind to the receptors sites on the post-synaptic neuron
what does action potential mean
the method by which the nerve impulse passes down the axon of the neuron to stimulate the release of neurotransmitters
what is a neurons resting membrane potential potential
-70 mz
why is a neuron depolarised
the inside is negative (-70mz) and the outside is positive
what happens to neurotransmitter molecules that have not been absorbed by receptors on the post-synaptic neuron (2 ways)
re-uptake
destroyed by enzymes
what is re-uptake
when a neurotransmitter is taken back to the neuron it came from through a transporter
what is serotonin responsible for
happiness and good mood
what is melatonin responsible for
regulates sleep-wake cycle
what is dopamine responsible for
pleasure and motivation
what is schizophrenia suggested to be caused by
excess of dopamine
describe the process of action potential
axon is surrounded by semi-permeable membrane
resting state of a membrane (-70mvz) nothing is being sent
some sodium (+) ions are pulled into the membrane (increases charge to -55mv)
causes ion channels to open (more positive ions reaches 40mv), then the message is sent
