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.
The nervous system consists of two major subdivisions: the CENTRAL NERVOUS SYSTEM (CNS) and the PERIPHERAL NERVOUS SYSTEM (PNS). The CNS consists of the BRAIN and SPINAL CORD. This is where almost all the important PROCESSING in the nervous system takes place.he best functional definition of an axon is that it is a nerve process which is capable of transmitting a nerve impulse (action potential) over some distance. The nervous system also contains cells which are not neurons and which do not DIRECTLY participate in the task of sending and receiving electrical signals.