Neuromuscular junction. Light micrograph of neuromuscular junctions, the connection points between a motor neurone axon (nerve fibre, dark branched) and the skeletal muscle fibres that it controls (reddish tissue bands). The end of a motor neurone axon divides into branches, each one terminating on a different muscle fibre. A single axon thereby has the ability to activate up to several hundred muscle fibres. The end of each branch divides to form a cluster of small swellings known as motor end plates on the muscle fibre surface. These activate and inhibit muscle activity.