15. Resting Membrane Potential

Electric nature of neaurons

• POlarized membrane

  • charge difference

• outside = +

• inside = -

• -70mv is resting potential

Resting potential of the memrbrane

• Extar celular fluid

  • higher con of

    • Cl-

    • Na+

    • Ca2+

• Cytosol

  • Higher conc of

    • K+

    • Proteins (anion)

• Charge created becuase of clumps of + or - ions near plasma membrane (immidiate inside/outside)

• ion conc result of 2 processes

  • Na/K+ pump

  • membrane permeability

membrance permeability

2 types of channels

1. leak ion channels

   • K+ leak more numorous

2. Gated ion channels

   • ligand gates

   • mechinacally gates

   • voltage gate d

• permieability corusponds to

  • # of open channels

  • size of ions

  • # of gated channels

    
    

How K+ ions and proteins contribute to the charge around the membrane/resting potential

• K+ ions leaving the cell through leak from area from high conc of K+ to a area of lower conc of K+

  • net positive charge on outside of cell

  • proteins on inside of cell start to move towards outside of cell

    • making negative inside

    • pulling K+ from outside back in

  • Eventually you get movement of K+ out = K+ in

    • reating potential

Characteristics responsible for the RMP (resting membrane…)