A graded potential is produced when a ligand opens a ligand-gated channel in the dendrites, allowing ions to enter (or exit) the cell. For example, Na⁺ will enter the cell and K⁺ will exit, until they both reach equilibrium.

How is the graded potential created in the sensory receptor?

A receptor potential, also known as a generator potential, a type of graded potential, is the transmembrane potential difference produced by activation of a sensory receptor. A receptor potential is often produced by sensory transduction. It is generally a depolarizing event resulting from inward current flow.

Where do action potentials occur?

Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, endocrine cells and in some plant cells.