3.3 The Cells Of The Nervous System And Neurotransmitters At Synapses Flashcards
Chemical neurotransmitter or a drug that mimics one
Agonist
Drug that inhibits transmission of nerve impulses
Antagonist
Neural fibre that conducts impulses away from the cell body
Axon
Pathway in which impulses from many neurons are passed to one neuron.
Converging neural pathway
Neural fibre that conducts impulses towards the cell body.
Dendrite
Decrease in number or sensitivity of synaptic receptors as a result of exposure to drugs.
Desensitisation
Pathway in which impulses from one neuron are passed to many.
Diverging neural pathway
Neurotransmitter involved in inducing the feeling of pleasure and other actions.
Dopamine
Neurotransmitter involves in reducing intensity of pain and other actions.
Endorphin
Signal that affects a receptor and which can be passed on.
Excitatory signal
Cell in the nervous us system that physically supports neurons and produces myelin sheaths.
Glial cells
Signal that affects a synaptic receptor but is not passed on.
Inhibitory signal
Conducts impulses within the CNS, linking sensory and motor neurons.
Inter neuron
Carries impulses from the CNS to muscles or glands.
Motor neuron
Insulation of nerve fibres with myelin sheaths.
Myelination
Layer of fatty insulation round a nerve fibre.
Myelin sheath
Conducting nerve cell.
Neuron
Chemical released into a synaptic cleft to transmit impulses to the next well.
Neurotransmitter
Process by which phagocytes engulf and destroy foreign material.
Phagocytosis
Capacity to form new neural pathways.
Plasticity
Membrane of the neuron that contains receptors for neurotransmitters.
Post-synaptic membrane
Membrane of the neuron that releases neurotransmitter.
Pre-synaptic membrane
Protein found in the post-synaptic membrane that binds neurotransmitter.
Receptor
Substance that changes neurochemistry; many are illegal.
Recreational drugs
Pathway that recycles impulses round the same route.
Reverberating neural pathway
Neural pathway that produces pleasure.
Reward pathway
Increase in the number or sensitivity of receptors as a result of exposure to drugs.
Sensitisation
Neuron that carries impulses into the CNS from a sense organ.
Sensory neuron
Junction between neurons.
Synapse
Gap between neurons at a synapse.
Synaptic cleft
Tiny vacuole containing neurotransmitter; found in pre-synaptic neurons.
Synaptic vesicle
