Term
| what is a synapse? what are the types? |
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Definition
-the junction where information is transferred in 1 of 3 ways:
1) from 1 neuron to another (neuro-neuronal)
2) from a neuron to a muscle (neuro-muscular)
3) from a neuron to a gland (neuro-glandular) |
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Term
| what way of synapse transfer is from a neuron to a gland? |
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Definition
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Term
| what is the presynaptic cell? |
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Definition
| -the neuron SENDING the signal |
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Term
| what is the postsynaptic cell? |
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Definition
| -the structure RECEIVING the signal |
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Term
| what are the two signals involved in neuron transmission? |
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Definition
1) presynaptic cell (neuron SENDING the signal)
2) postsynaptic cell (structure RECEIVING the signal) |
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Term
| what are the 2 functional types of synapses? |
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Definition
1) electrical synapse: cells are joined by specialized cellular adhesions (gap junctions)
2) chemical synapse: specialized for release and reception of neurotransmitters |
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Term
| what type of functional synapse is more common? |
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Definition
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Term
what are gap junctions?
function?
where found? |
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Definition
-specialized cellular adhesions in electrical synapses
-allow electricity to flow very quickly from cell to cell
-ex: heart |
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Term
| what are neurotransmitters? |
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Definition
-released and received in chemical synapses
-convert electrical signals into chemical signals |
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Term
| how do neurotransmitters convert electrical signals into chemical signals? |
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Definition
-the chemical signal travels across the synapse to the post-synaptic structure
-then it is converted back into an electrical signal |
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Term
| what are the factors that tell whether the postsynaptic structure can be excited or inhibited? |
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Definition
-neurotransmitter
-receptor
-type of ion channel that receptor is associated with |
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Term
| what is excitatory postsynaptic potential? (EPSP) |
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Definition
-a neurotransmitter binding to its receptor causes ion channels that allow depolarization to open
-membrane becomes more positive on the inside and is brought closer to threshold
-mostly associated with chemically-gated sodium channels |
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Term
| in EPSP (excitatory postsynaptic potential) what causes ion channels that allow depolarization to open? |
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Definition
| -a neurotransmitter binding to its receptor |
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Term
| what charge does the inside of the membrane become during EPSP? where does it go? |
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Definition
-membrane becomes more positive on the inside
-brought closer to threshold |
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Term
| which channel is excitatory postsynaptic potential mainly associated with? |
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Definition
| -chemically-gated sodium channels |
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Term
| what is inhibitory postsynaptic potential? (IPSP) |
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Definition
-a neurotransmitter binding to its receptor causes ion channels that allow hyperpolarization to open
-membrane becomes more negative inside and is taken further away from threshold
-mainly associated with chemically-gated potassium channels (w/ potassium efflux) OR chemically-gated chloride channels (w/ chloride influx). |
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Term
| what does a neurotransmitter binding to its receptor cause in IPSP? |
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Definition
| -causes ion channels that allow hyperpolarization to open |
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Term
what charge is the inside of the membrane with an IPSP?
-where is it taken? |
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Definition
-more negative on the inside
-further from threshold |
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Term
| which channel is inhibitory postsynaptic potential mainly associated with? |
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Definition
-chemically-gated potassium channels (with potassium efflux)
-chemically-gated chloride channels (with chloride influx) |
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