Electrical Signals in Neurons

1. Electrical Signals
in Neurons
Ade Wijaya, MD – January 2019
Source: Principles of Anatomy and Physiology: GERARD J. TORTORA

2. Outline:
▪ Ion channels
▪ Resting membrane potentials
▪ Graded potentials
▪ Action potentials

3. Ion Channels

6. Resting Membrane Potentials

9. Graded Potentials

10. ▪ A graded potential is a small deviation from the membrane
potential that makes the membrane either more polarized
(inside more negative) or less polarized (inside less negative)
▪ A graded potential occurs when a stimulus causes
mechanically gated or ligand-gated channels to open or close
in an excitable cell’s plasma membrane
▪ Graded potentials occur mainly in the dendrites and cell body
of a neuron

13. Action Potentials