ABSTRACT
Neurones are highly specialised cells that receive, assimilate, and transmit information. The neurone has a cell body that maintains its functional and structural integrity. Fine processes emanate from the cell body and divide further into finer processes. These structures are known as dendrites and their complex network is the dendritic tree. The effect of the dendritic tree is to greatly increase the surface area of the cell body that is available to make contact with other neurones at synapses. The size and extent of the dendritic tree varies enormously but some large cells in the brain can have up to 10000 synapses. The dendrites are the area of the neurone where electrical stimuli are received and integrated. The cell body which contains the nucleus, is connected to an axon along which nerve impulses are propagated. Neurones can conveniently be divided functionally into four areas: (1) a receptor zone where synaptic connections are integrated, (2) an area where nerve impulses originate, (3) the axonal process that transmits the propagated impulse, and (4) the nerve ending where synaptic transmitters are released. Diagrammatic representations of motor and sensory neurones are shown in Figures 11.1 and 11.2.
