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Which branching part of a neuron receives messages from other neurons?
At most connections between neurons, the message crosses a tiny gap as a chemical.
Measurements show the human brain has about 100 billion neurons and ten times as many glial cells.
Which animal's nervous system has the most neurons?
A neuron rests at about −70 mV and an action potential peaks at about +40 mV. How many millivolts does the membrane potential change from rest to peak?
What effect does myelin have on an axon?
What does it mean to say an action potential is 'all-or-nothing'?
Why can a neuron not fire a second action potential immediately after the first?
Describe, in order, how a signal is passed across a chemical synapse once an action potential reaches the axon terminal.
A chemical synapse can make the next neuron less likely to fire.
Azevedo et al. (2009) report 86.1 ± 8.1 billion NeuN-positive cells in the adult male human brain. State two assumptions or limits a careful reader should keep in mind when quoting '86 billion neurons'.
