W YORK NE NmN、d三 Describe the maintenance of resting potential in a cell Explain how a cell is induced exciting Contrast graded potentials and action potentials Describe how a cell has refractory phaseLEARNING OBJECTIVES  Describe the maintenance of resting potential in a cell  Explain how a cell is induced exciting  Contrast graded potentials and action potentials  Describe how a cell has refractory phase