"Acetylcholine is the major neurotransmitter at the neuromuscular junctions of the body. The Humanoids seem very interested in the biochemistry of our nervous system." (Dr. Bruce Grey)
QUESTION:
For a neurotransmitter to act on a muscle, it must first cross a tiny gap called the ________.
![[ Level 4 ]](cs4_biolevel_1_4.jpg)
