Summary Listen

Our nervous system is organised into two main systems: the central nervous system and the peripheral nervous system. In both we find neurones and glial cells that provide neuroprotective support in terms of nutrition, insulation and protection to these neurones. A nerve cell’s main task is to send nerve impulses to other nerve cells, muscle cells or glandular tissue. The nerve impulse is an electrical impulse which is controlled by sodium and potassium movements in an out of the cell in the form of an action potential. When a nerve impulse enters the axon terminal it releases a neurotransmitter, such as acetylcholine, into the synaptic cleft. These neurotransmitters stimulate or inhibit the postsynaptic nerve cell. A new nerve impulse is generated in the axon when the threshold membrane potential necessary for the spontaneous opening of sodium channels in the cell membrane is achieved by the summation of all of the stimulatory (excitatory) and inhibitory synapses on the cell body and dendrites of that cell.