Synapse-Anatomy

SYNAPSE-ANATOMY

Functional anatomy of the synapse 

  • A typical motor neuron (efferent neuron) shown under electron microscope numerous (average about 6000) small knobs spread over the surface of the dentrites (80-90%) and soma (10-20%).  These knobs are the ends of nerve fibrils that have their origin in many other neurons (usually not more than a few derived from any single previous neuron). The knobs are referred to as presynaptic terminals or terminal knobs, buttons, end feet and synaptic knobs.

Synapse

  • Neurons in other parts of the cord and brain differ markedly from the motor neuron in the following features :
    • Size of the soma
    • Size, length and number of dentrites (ranging in length as long as many centimeters)
    • Size and length of axon
    • The number of presynaptic terminals (range from few to more than one hundred thousand).
  • These differences are responsible for the neurons of the different parts of the nervous system to react diversely to incoming signals in their functions.
Last modified: Thursday, 26 May 2011, 6:12 AM