Neurons transmit electrical JXUwMDMxJXUwMDA0JXUwMDFkJXUwMDA1JXUwMDE5JXUwMDFmJXUwMDE2JXUwMDE2 when they are JXUwMDJiJXUwMDA3JXUwMDFkJXUwMDA0JXUwMDE4JXUwMDE5JXUwMDBkJXUwMDE1JXUwMDExJXUw MDAx .

In JXUwMDM1JXUwMDAyJXUwMDFiJXUwMDFiJXUwMDFk neurons the cytoplasm forms a long fibre surrounded by a cell membrane called an JXUwMDM5JXUwMDE5JXUwMDE3JXUwMDAx .

Some axons are surrounded by a fatty JXUwMDJiJXUwMDFiJXUwMDBkJXUwMDA0JXUwMDE1JXUwMDFj , which insulates the neuron from neighbouring cells and increases the JXUwMDJiJXUwMDAzJXUwMDE1JXUwMDAwJXUwMDAx of a nerve impulse.

There are gaps between neurons called JXUwMDJiJXUwMDBhJXUwMDE3JXUwMDBmJXUwMDExJXUwMDAzJXUwMDE2JXUwMDE2 .

At the end of a sensory neuron an impulse triggers the release of JXUwMDNiJXUwMDBiJXUwMDBkJXUwMDA4JXUwMDA0JXUwMDBhJXUwMDAyJXUwMDBkJXUwMDFm into the synapse, which JXUwMDNjJXUwMDBkJXUwMDBmJXUwMDAwJXUwMDEzJXUwMDA2JXUwMDE2 across and bind to JXUwMDJhJXUwMDE3JXUwMDA2JXUwMDA2JXUwMDE1JXUwMDA0JXUwMDFiJXUwMDFk molecules on the membrane of a motor neuron.

The receptor molecules only bind to JXUwMDJiJXUwMDAzJXUwMDE1JXUwMDA2JXUwMDBhJXUwMDBmJXUwMDBmJXUwMDBh chemicals, triggering a nerve impulse in the motor neuron.

A = JXUwMDM2JXUwMDFiJXUwMDE2JXUwMDBmJXUwMDA5JXUwMDEwJXUwMDA2

B = JXUwMDNiJXUwMDFhJXUwMDBkJXUwMDFiJXUwMDFmJXUwMDFjJXUwMDBkJXUwMDEyJXUwMDFl

C = JXUwMDM5JXUwMDE5JXUwMDE3JXUwMDAx

D = JXUwMDJiJXUwMDFiJXUwMDBkJXUwMDA0JXUwMDE1JXUwMDFj