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Nervous system - Coggle Diagram

- - - - synapses
        
        where communication takes place between neuron's
        
        hundreds of trillions
  - - - reception of information
    - - protein synthesis site
      - keeps the neuron alive
    - - from a few mm to more than a meter
      - propagates electrical signals
    - - link between soma and axon
    - - communication
        
        with cells that are not neurons
        
        with other neurons
  - - - small excess of negatively charged ions inside the neuron
        
        different concentration gradients of various physiological ions
        
        selective permeability of the membrane to different physiological ions
        
        highly permeable to K+
        
        diffusion is therefore only through ion channels
        
        concentration gradient pushes K+ out of the neuron
        
        electrical gradient pulls K+ into the neuron
        
        K+ does NOT diffuse until concentration is the same inside and out
        
        as the K+ goes out, inside becomes more neg, and electrical gradient hence pulls positive K+ back in, much before the concentration of K+ outside can equal the one inside
        
        when these are equal ^^^ = equilibrium of charges
        
        Nernst equation
        
        for K+, equilibrium potential around -90mV
        
        1 more item...
        
        important!!
        
        VIRTUALLY THE SAME AMOUNT OF CHARGES INSIDE AND OUTSIDE NEURON MEMBRANE!!!
        
        remember that the polarity is due to concentration gradient and movement of ions
- - - - afferent
        
        sensory
      - efferent
        
        motor
        
        automatic