Question

To result in an action potential in the central nervous system, EPSP's must ____ through temporal and spatial summation to ____ threshold voltage.

O add up; exceed
O accelerate; reach
O flow; polarize
O sum; activate

Answer 1

They have to sum ;active

Answer 2

accelerate; reach

Step-by-step explanation:

EPSPs fire to trigger action potentials in the postsynaptic cell, by getting the membrane potential to threshold at the axon hillock true, or initial segment of the axon

synaptic knob can fire several times, as others fire as well, so EPSPs can be summed or added; the whole cell body depolarizes, causing current flow, eventually causing an AP to propagate down the axon if brought to threshold at the axon hillock/initial segment.

-remember, as one synaptic knob firing causes 0.5mV charge, you need much more than one to get to threshold.

T/F: if a knob is closer to the axon hillock, more charge will get to it

EPSPs, as described above, are what happens in efferent neurons, which go to effectors, and in interneurons, which are found in the CNS between afferent and efferent neurons

-we already covered afferent neurons, which cause APs to fire in the membrane next to the receptor (toward the CNS)