How does a thought move a muscle? A nerve signal reaches the muscle. It hands off a chemical message, acetylcholine, that sparks the fiber to contract. Step through the handoff.
The signal arrives
The NMJstep 1 of 5
📷 Reference image
A real labeled figure to compare with the interactive above.
The Neuromuscular Junction — OpenStax, CC BY 4.0 (via Wikimedia Commons)
