ECG C3: Heart Electrical Physiology

Cardiac muscle working cells create a _________ before relaxing the cardiac muscle.

muscle contraction

__________ cells have a primary function to _________ electrical impulses.

Pacemaker; generate

An electrical function unique to pacemaker cells is called _________, whereas the unique mechanical function of pacemaker cells is called __________.

automaticity; contractility

A normal health adult heart will complete the cardiac cycle ________ times in 1 minute, which is approximately once every ________ seconds.

60-100 times; 8

In a cardiac cell’s resting state, the electrolyte will carry a ________ charge.

Negative

Water follows _______ in the body, and when there is too much of this electrolyte, the brain signals for the person to _________ water.

Sodium; drink more

___________ is responsible for terminating the action potential of cardiac muscles, thus when there is too little of this electrolyte, premature _________ can occur.

Potassium; contractions

The electrolytes __________ and ___________ work together to cause muscle contractions.

calcium; sodium

_________ is the second-most-abundant electrolyte in the body, yet is most likely to be extremely _______ because it is usually expelled.

Magnesium; low

Potassium and magnesium carry a ________ charge when the cardiac cells are at rest.

Negative