biopsychology - neurons and synaptic transmission Flashcards
what are neurons?
building blocks of the brain and nervous system
what is synaptic transmission?
the process by which neurons communicate with each other
purpose of motor neuron
send messages from brain and spinal cord to muscles and glands
physical characteristics of motor neuron
short dendrites
long axons
purpose of sensory neuron
send messages from sense organs to the spinal cord and brain (CNS)
physical characteristics of sensory neuron
long dendrites
short axons
purpose of relay neuron
to connect motor and sensory neurons together
physical characteristics of the relay neuron
short dendrites
short axons
how do neurons work?
negatively charged at rest
stimulated by nearby neuron and becomes momentarily positively charged
- causes an action potential to travel down the axon
terminal buttons transmit the signal to other neurons
what is the cell body (soma)?
includes a nucleus which contains general material for the cell
what are dendrites?
branchlike structures that protrude from the cell body
carry nerve impulses from neighbouring neurons to the cell body
what is the function of the axon?
carries impulses away from the cell body down the length of the neuron
what is the myelin sheath?
fatty layer than protected the axon
is segmented by gaps to speed up electrical transmission
what are Nodes of Ranvier?
gaps in the myelin sheath which speed up transmission of electrical impulse by forcing it to ‘jump’ across gaps
what are the terminal buttons?
found at the end of the axon
communicate with the next neuron across the synapse
what is action potential?
the electrical signal caused by change in electrical charge
process of synaptic transmission
action potential reaches the terminal buttons and synaptic vesicles release neurotransmitter into synapse
neurotransmitter stimulates dendrites of neighbouring neurons
- either excites them to fit of inhibits them so they don’t fire
what is re-uptake?
after the neurotransmitter has stimulated adjacent neurons, it is reabsorbed by the terminal button
what is summation?
individual neuron receives many inputs from adjacent neurons
sums the excitatory and inhibitory inputs as to whether it should fire or not
strength - real-world application
drug treatments work by modifying synaptic transmission
e.g SSRIs prevent reuptake to increase effect
some block receptor sites to reduce effect of neurotransmitter
