3.4 Flashcards
what is the function of the cell body of a neurone
contains nucleas and most of the cytoplasm
what is the function of a dendrite
nerve fibres that receive nerve impulses and pass them towards a cell body
what is the function of an axon
single nerve fibre that carries nerve impulses away from a cell body
what is the myelin sheath
a layer of fatty material that insulates the axon
why is insulating the axon important
tu increase the speed of impulses conduction and to protect the thin axon
when does myelination happen
birth to adolescence
what are glial cells
produce myelin sheath and support neurons
what are neurotransmitters
types of chemicals
how does an impulse pass through the pre synaptic neurone
- impulse stimulates bessickes to move to the synapse
- fuse to the membrane
- discharge neurotransmitters which diffuse accords the synapse
- bind to receptors
how does enzyme degeneration work
neurotransmitters are broken down by enzymes
how does reuptake work
neurotransmitters are taken back up directly by the presynaptic membrane
what determines wether the signal is excitatory or inhibitory
the receptors on the post synaptic neurone
what needs to happen for an impulse to be transmitted
a certain threshold has to be reached
what is summation
the collection of weak stimuli to start an impulse
what are endorphins
neurotransmitters that stimulate neurons involved in reducing intensity in pain, by reducing the transmission of the pain signal
what is dopamine
neurotransmitters that induce feelings of pleasure by stimulating the reward pathway
what are neurotransmitter related disorders
schizophrenia
alzheimer’s
anxiety disorders
what is an antagonist treatment
mimics neurotransmitters by binding to the receptor
what is a antagonist treatment
blocks receptor by binding to them
how do recreational drugs work
affects transmission at synapses in the brain
what does repeated use of an antagonist do
causes drug addiction
what does repeated use of an agonist do
drug tolerance
what is drug addictions effect on receptors
increases the number of receptors and the sensitivity of receptors
what is drug tolerance affects on receptors
decreases sensitivity and number of receptors
what is drug tolerances effect
requires more of the drug for an effect
what is drug addictions effect
need the drug to feel normal
