Summations

Question 1

what is summation?

Answer 1

the effects of neurotransmitters released from many neurones, or one neurone that stimulated a lot in a short period of time is added together

Question 2

what are the two types of summation?

Answer 2

• temporal summation
• spatial summation

Question 3

what is spatial summation?

Answer 3

• where two or more presynaptic neurones release their neurotransmitters at the same time onto the same postsynaptic neurone
• the small amount of neurotransmitter released from each of theses neurones can be enough altogether to reach threshold in postsynaptic neurone and trigger an action potential

Question 4

what happens in spatial summation if some neurones release inhibitory neurotransmitters?

Answer 4

total effect of all neurotransmitters would be no action potential

Question 5

what is temporal summation?

Answer 5

when two or more nerve impulses arrive in quick succession from the same presynaptic neurone
- action potential is more likely as the neurotransmitters are released into the synaptic cleft