Nervous system would not exist without the human brain. Most neurons send signals via their axons, although some types are capable of dendrite-to-dendrite communication. (In fact, the types of neurons called amacrine cells have no axons, and communicate only via their dendrites.) Neural signals propagate along an axon in the form of electrochemical waves called action potentials, which produce cell-to-cell signals at points where axon terminals make synaptic contact with other cells. Synapses may be electrical or chemical. Electrical synapses make direct electrical connections between neurons, but chemical synapses are much more common, and much more diverse in function. At a chemical
Common Source Data Base Common Source Data Base Technical documentation is used in many areas of the everyday life. Nearly everything has to be provided with at minimum a drawing including a few locators. The product liability and many other issues regarding consumer protection have to be covered inside technical documentation. A special form of technical documentation is electronic technical documentation, a further subform is interactive electronic technical documentation (IETD). The complexity of IETD especially regarding the huge mass of data elements, their linkage and the version management issuing and release process must be controlled via a special document management system. To handle these