Aluminium versus aluminum. Following up a Topical Words piece on the international spelling of what British English writes as sulphur, many American subscribers wrote in to ask about another element with two spellings: aluminium.
The simplest and presumably most primitive form of nervous system is termed a nerve net. In a nerve net, neurons are dispersed in a thin layer, not clustered into nerves or a central nervous system (CNS), and they are positioned seemingly at random relative to each other.he simplest and presumably most primitive form of nervous system is termed a nerve net. In a nerve net, neurons are dispersed in a thin layer, not clustered into nerves or a central nervous system (CNS), and they are positioned seemingly at random relative to each other.
Cells of the Nervous System. The nervous system is made up of two types of cells: neurons and glia. Neurons are the fundamental cellular unit of the central nervous system (CNS) and peripheral nervous system (PNS). Essential features of neurons:1  The purpose of neurons is to receive, process, and transfer information.2  This information is made up of chemical or electrical signals.ells of the Nervous System. The nervous system is made up of two types of cells: neurons and glia. Neurons are the fundamental cellular unit of the central nervous system (CNS) and peripheral nervous system (PNS). Essential features of neurons: