Neurons are the structural and functional units of the nervous system.
Connections can be made neuron to neuron or neuron to axon.
Axons are connected to structural and functional units of the nervous system.
What are connected to structural and functional units of the nervous system?

1) eardrum
2) axons
3) bacteria
4) cilia
5) organ
6) motors
7) skin cells
8) nerves