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 is a complex, sophisticated system that and regulates and coordinates body activities and its interaction with the external environment.It has two major parts-the central nervous system and the peripheral nervous system. The central nervous system comprises of the brain and spinal cord.he central nervous system consists of the brain and spinal cord, the peripheral nervous system consists of all of the other nervous tissue in the body such as the nerves going to and from the spinal cord and the nerves in the limbs.