Conversation so far:
what is the job of a motor neuron
A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch.
where is the motor neuron located
A motor neuron is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord.
what types of motor neurons are there
There are two types of motor neuron – upper motor neurons and lower motor neurons.

Question: what is an upper
Self-contained rewrite: what is an upper motor neuron