Before the heart muscle can contract, it must receive an electrical signal called a(n) ______________.

Question

Quizplus · Accepted Answer

An action potential is an electrical impulse that travels through nervous and muscle tissue in order to elicit a response. In the heart, this action potential originates at the sinoatrial node and is propagated through the heart tissue to stimulate contraction of the heart. Without this signal, the heart will not be able to contract, or pump blood.
A resting membrane potential (RMP) is the state of a muscle or nerve cell that must exist in order for an AP to be received and transmitted. Therefore prior to an AP arriving, a certain RMP must exist. So this is important for heart contraction to occur, however this refers more to the state of the cardiac muscle cell as opposed to the active signal the cell receives.
A local potential is what precedes an action potential. For an action potential to develop, a local potential is initiated first. As long as the local potential is strong enough, it will become an action potential.
A graded potential is a type of local potential, and thus would precede an action potential.

Before the Heart Muscle Can Contract, It Must Receive an Electrical