MEMBRANE POTENTIAL
● In all types of cells, there is an. Electrical potential difference
between the inside of the cell and the surrounding extracellular
fluid. This is termed as the membrane potential of the cell.
● It is important in nerve and muscle cells, because changes in their
membrane potentials are used to transmit information.
● Membrane potentials are measured in units of volts.
Resting membrane potential
Excitatory post -synaptic potential
Inhibitory post – synaptic potential
Action potential
RESTING MEMBRANE POTENTIAL: Neurons have a selectively
permeable membrane.
● During resting conditions membrane is ,
o Permeable to potassium ions channels are open
o Impermeable to sodium ions channels are closed.
● Diffusion force pushes potassium out ( concentration gradient) .
● This creates a positively charged extra cellular space.
● Electropositive force pushes potassium ions in.
● Thus, there is a dynamic equilibrium with zero net movement of
ions.
● The resting membrane potential is negative (-60mV).
EXCITATORY POST- SYNAPTIC POTENTIAL:
● The pre – synaptic neuron release a neurotransmitters.
● Neurotransmitters diffuses across extra cellular space synaptic
cleft.
● In all types of cells, there is an. Electrical potential difference
between the inside of the cell and the surrounding extracellular
fluid. This is termed as the membrane potential of the cell.
● It is important in nerve and muscle cells, because changes in their
membrane potentials are used to transmit information.
● Membrane potentials are measured in units of volts.
Resting membrane potential
Excitatory post -synaptic potential
Inhibitory post – synaptic potential
Action potential
RESTING MEMBRANE POTENTIAL: Neurons have a selectively
permeable membrane.
● During resting conditions membrane is ,
o Permeable to potassium ions channels are open
o Impermeable to sodium ions channels are closed.
● Diffusion force pushes potassium out ( concentration gradient) .
● This creates a positively charged extra cellular space.
● Electropositive force pushes potassium ions in.
● Thus, there is a dynamic equilibrium with zero net movement of
ions.
● The resting membrane potential is negative (-60mV).
EXCITATORY POST- SYNAPTIC POTENTIAL:
● The pre – synaptic neuron release a neurotransmitters.
● Neurotransmitters diffuses across extra cellular space synaptic
cleft.
