I wonder why is it called plasma membrane - what's the biological meaning of the word 'plasma'?
I thought it was a no-brainer, apparently it's more of a historical journey into the origins of Botany. But I have a hypothesis: During the debate of whether the cell or the fluid within it was the origin of life, that fluid was called 'protoplasm' - first formed, i.e. it's the origin of life. The plasma membrane, then, is simply that which surrounds the 'plasma' - the protoplasm.