What is meant by functional unit of a system?
Like when we say that the neuron is the basic unit of neural system, do we mean that all those things that are performed by neural system can be performed by an isolated neuron?
If yes, how? And if not, then why do we call it as functional unit of neural system?
Like we say hepatic lobule functional unit of the liver is not hepatocytes, because we say that liver has complex functions, and single hepatocytes cannot perform it. So the functional unit of liver is the hepatic lobule.
Basically I am asking can a single neuron perform the most complex functions of neural system: like memory storage, control and coordination (to a smaller extent) regulation of a cell.
How can a single neuron control or regulate another cell, because wouldn't it need other neurons for processing of stimulus?
Can an isolated neuron process any stimulus and make other cell to respond in some way? If not so why we call it the functional unit of neural system?