1.motor neuron

2. sensory neuron

3.interneuron

The patellar reflex is an example of a 2-neuron reflex arc. It has 1 sensory neuron and 1 motor neuron. It does not contain an association neuron and so is considered the most simple reflex in humans.

it only has 1

1. The neuron fires an action potential, sending the electrical signal down the axon.

Neurotransmitters released by 1 nerve cell are received by another neuron. The receptor of a postsynaptic neuron receives the neurotransmitters.