Neuron

• NEURON


  -       or the nerve cell

  -       the basic structural and functional unit of the nervous system

  -      a cell in the nervous system whose function it is to receive and transmit information
• Components and Parts of Neuron

  
• PART OF THE NERVE CELL

  -       Cell Body

  -       Dendrites

  -       Axon
• COMPONENTS OF THE NERVE CELL

  -          Myelin Sheath

  -          Terminal Button

  -          Glial Cells (Glia)
• Myelin Sheath


  -          a layer of fatty tissue surrounding the axon of a neuron that both acts as an insulator

  -          allows faster transmissions of the electoral signal
• Terminal Button


  -          this is at the tip of each branch when axon branch out towards their end

  -          forms junctions with other neurons
• Glial Cells (Glia)


  -          cells that surround and link to the neurons, protecting them, providing them with nutrients, and absorbing unused neurotransmitters
• NEURONS ARE GROUPED INTO THREE, ACCORDING TO THEIR FUNCTIONS


  -          Sensory or Afferent Neurons

  -          Motor or Efferent Neurons

  -          Inter-neurons, Connector Neurons or Association Neurons
• Sensory or Afferent Neurons

  -          carry messages or nerve impulses from the sense organ toward the brain/central nervous system
• Motor or Efferent Neurons


  -          carry messages or nerve impulses away from the brain, like muscle and glands
• Inter-neurons, Connector Neurons or Association Neurons


  -          carry messages or nerve impulses within the brain/central nervous system
• CHARACTERISTICS OF A NEURON

  -          Irritability

  -          Conductivity
• Irritability


  -          characteristic of a neuron

  -          the ability of neurons to react to external stimulations
• Conductivity


  -          characteristic of a neuron

  -          the ability of neurons to transmit nerve impulses up to the end of the nerve fiber
• NERVE IMPULSE


  -          Stimulus

  -          Electric Signals

  -          Resting Potential

  -          Action Potential

  -          Synapses
• Stimulus


  -          nerve impulse that refers to anything that excites or initiates an activity
• Electric Signals


  -          nerve impulses or messages
• Resting Potential


  -          or polarization stage

  -          under nerve impulse

  -          more negative than positive ions or charged particles inside the neuron, while it has more positive ions outside
• Action Potential


  -          sending of a nerve impulse 

  -          ‘firing’ of a neuron down the axon from the end of one neuron to the next neuron
• Synapses


  -          under nerve impulse

  -          spaces between the axon of neuron
• LAW OF GOVERNING NEURON

  -          All or Nothing Law

  -          Law of Dynamic Polarity
• All or Nothing Law


  -          states that it is either that neuron reacts or not at all, but if it does react, it reacts with fullest strength
• Law of Dynamic Polarity


  -          states that nerve impulses travel only in one direction from neuron to neuron