One of the main functions of the nervous system is communication, as already described, which it achieves via signaling through electrical impulses and chemical processes. But possibly more tangibly, a really important function of the nervous system is controlling the body. Information comes in via sensory receptors, is transmitted to the brain where it is processed in order to work out what the most appropriate response should be, and then messages are sent out to the relevant part of the body in order to enact that response. 

Humans have incredibly evolved and complex nervous systems, which means they not only have integrated processing that allows many things to occur at once in the body in response to something happening externally, but beyond that there are much more sophisticated functions such as language, conceptual thinking and nuanced social interactions – all the things that give us life rather than simply existence.

So far this module has pulled no punches in detailing the extreme complexity and intricacy of the nervous system, from the multifaceted brain and many-branched spinal cord to the tiny neuronal dendrites and all-important neurotransmitters. Such complexity means that there is a lot that can go wrong.