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Dendrites – Structure and Functions

  • image descriptionDendrites are often, but not always, branched cytoplasmic processes that attach to one side of the cell body.
An image of a neuron showing the dendrites in separated illustration (expand)
An image of a neuron showing the dendrites (which is labeled) in separated illustration (expand)
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  • They contain many of organelles found in the cell body, which perform the same metabolic functions.
  • Dendrites make up most of the receptive zone of a neuron and can detect specific changes in the surrounding environment (stimuli).
  • For example, CNS dendrites have membrane receptors that respond to image descriptionneurotransmitter molecules released by the axons of nearby neurons.

Take your nervous system anatomy knowledge to the next level with these interactive quizzes, worksheets and labeled diagrams.

  • The neurotransmitters serve as a stimulus because they change the environment around the dendrites.
  • When the neurotransmitters bind to the dendritic receptor, chemical gates open and surrounding image descriptionion diffuse through the receptor channels.
  • The ion exchange image descriptionalters the polarity of the dendritic membrane.
  • The inside of the receptive relative zone becomes increasing positive relative to the outside.
  • If the charge difference reaches a threshold level, it triggers electrochemical events in the axon process of a neuron.
  • Dendrites in other parts of the body are receptive to different types of chemical and mechanical stimuli, such as light, touch, stretch, temperature, etc.
  • When detected, these stimuli cause similar electrochemical changes to occur in the responding dendrites.