3 The Concept Of The Synapse Flashcards
gaps between neurons
where neurons communicate by transmitting chemicals ]
synpase
automatic muscular responses to stimuli
reflexes
circut from sensory neuron to muscle response
reflex arc
repeated stimuli within a brief time have cumulative effect
light pinch of a dog’s foot
temporal summation
the cell that receives a message
postsynaptic neuron
the cell that delivers a message
pre-synaptic neuron
glands that produce hormones
endocrine glands
epinephrine, norepinephrine, insulin, and oxytocin serve both as ________ & ________
neurotransmitters, hormones
a neurotransmitter does not linger at postsynaptic membrane it:
either inactivated or reabsorbs (reuptake)
in certain brain areas, presynaptic neuron takes up most of the released neurotransmitter molecules intact and reuses them
reuptake
graded depolarization; occurs when sodium ion enter the cell
excitatory postsynaptic potential (EPSP)
synaptic inputs from various locations combine their effects on a neuron
several small stimuli on a similar location produced a reflex when a single stimuli didn’t
spatial summation
spatial summation is critical to brain functioning
each neuron recieves many incoming axons that frequently produce _______ responses
synchronized
temporal and spatial summation ordinarily occur _____
together
input from an axon hyperpolarizes the postsynaptic cell
inhibitory synapses
occurs when the synaptic input selectively opens the channel fro potassium ions to leave the cell or for chloride ions to enter the cell
inhibitory postsynaptic potential (IPSP)
periodic reprouction of action potentials even without synaptic input
spontaneous firing rate
IPSP ______ # of action potentials about spontaneous firing rate
decrease
EPSP _______ # of action potentials about spontaneous firing rate
increase
sequence of chemical events:
synthesize, action potential, neurotransmitters released at synaptic cleft, diffuse, separate, reuptake, reverse message
synthesize, action potential, neurotransmitters released at synaptic cleft, diffuse, separate, reuptake, reverse message
chemicals released by one neuron that affect a secon neuron
neurotransmitter
tiny packets that store high concentrations of neurotransmitters
vesicles
effects that begin quickly and last for very brief period of time
excitatory- glutamate
inhibitory- GABA
ionotropic effects
initiates a series of metabolic reactions; slower and longer lasting than the other effects
metabotropic effects
neuromodulators, have several properties that distinguish them from neurotransmittters
neuropeptides
chemicals that are secreated by a gland or ther cell and conveyed by the blood tothe other organs
hormones
a drug that blocks the effects of a neurotransmitter
antagonist
a drug that mimicsor increases the effects
agonist
a drug has _____ for a receptor if it bind to it
fitting the lock
affinity
a drug’s tendency to activate the receptor
turning the lock
effinity
why do drugs effect different people differently
everyone varies in the number of receptors that the drug will influence
increase excitement, alertness, and activity, while elevating mood and decreasing fatigue
stimulant drugs
stimulates dopamine synapses by increasing release of dopamine from presynaptic terminal
amphetamine
blocks the reuptake of dopamine, norepinephirine, and serotonin
cocaine
morphine, heroine, methadone
relax people, decrease attention to real world problems and sensitivity to pain
opiates
How does alcohol affect neurons?
Facilitates response at _____ receptor
Block activity at ______ receptor
GABA, glutamate
