Neurones

Neurones

Neurones carry signals from and to each other and the motor and sensory organs. The signals are transmitted along neurones electrically as action potentials and from axon to dendrite (or end organ) as chemical messages via the synapse.

Structure:

Neurones consist of a cell body, numerous dendrites, an axon and synapses. The cell body houses the nucleus and all of the biochemical machinery for the cell's function. Besides spurious exceptions, neurones have one axon. The axon is the single output of the neurone, transmitting the action potential from the axon hillock to the synapse at its distal end. the synapse is where the electrical signal is transduced to a chemical message sent to the dendrites of other neurones. Axons are commonly myelinated to improve their speed of conduction, in the PNS this is done by Schwann cells and oligodendrocytes in the CNS. The dendrites are numerous and collect signals from many axons and transmit them to the cell body where they are collated and will either excite or inhibit the neurone from firing an action potential along its axon.