Cardiac output is normally expressed as

liters per minute.

The sinoatrial (SA) node is referred to as the _____________ of the heart.

pacemaket

When blood is flowing out of the left ventricle, the bicuspid valve is __________ and the aortic semilunar
valve is __________.

closed/ open

Excess potassium ions in cardiac tissue will cause the heart rate and stroke volume to

decrease

Coronary arteries are _____ when all four heart chambers are relaxed.

patent (open)

During which event of the cardiac cycle are all four valves closed while both the atria and ventricles relax?

isovolumetric relaxation

Because the ventricular myocardium is compressed during ventricular _______, most coronary flow occurs during ventricular _______.

contraction/ relaxation

What variables determine the effects on cardiac output?

changes in both HR and SV

Without a plateau extending the refractory period in cardiac muscle, sarcomeres might be stimulated so quickly that they would contract and not relax and instead would experience a sustained contraction, also called

tetany

Oxygenated blood flows from the __________ to the __________ before being pumped into the systemic circulation.

left atrium; left ventricle

Which of the following does not contribute to the ability of cardiac muscle to meet it's energy demands?

Glycolytic enzymes

What is the correct order of spread of the action potential through the heart's conduction system?

SA node, AV node, AV bundle, Purkinje fibers/cell gap junctions

During which event of the cardiac cycle do the atria both relax and contract?

Ventricular filling

Referred pain, often down the left shoulder and arm, in response to myocardial ischemia is called

angina pectoris.

What is the correct order of mechanical events associated with cardiac muscle contraction?

Calcium entry into the sarcoplasm, calcium binds to troponin, muscle contracts, closing of calcium channels, calcium released from troponin, muscle relaxes

Given that cardiac output equals ____________, there are only two ways to change it: change the heart rate or change the stroke volume.

HR X SV