Anatomy and Physiology Cardiovascular System 3

Question 1

On an electrocardiogram (ECG), the P wave represents:

Accepted Answer

Atrial depolarization

Answer

Ventricular depolarization

Answer

Atrial repolarization

Answer

Ventricular repolarization

Question 2

During which phase of the cardiac cycle do the ventricles primarily fill with blood?

Accepted Answer

Diastole

Answer

Systole

Answer

Isovolumetric contraction

Answer

Ejection phase

Question 3

Cardiac output is calculated by multiplying:

Accepted Answer

Heart rate × stroke volume

Answer

Blood pressure ÷ heart rate

Answer

Stroke volume ÷ heart rate

Answer

End-diastolic volume − end-systolic volume only

Question 4

The Frank-Starling law of the heart states that:

Accepted Answer

The heart contracts more forcefully as ventricular filling (preload) increases

Answer

Increased heart rate always decreases stroke volume

Answer

Cardiac output remains constant regardless of changes in preload

Answer

Decreased preload increases myocardial contractility

Question 5

Which ion plays the primary role in triggering cardiac muscle contraction?

Accepted Answer

Calcium (Ca2+)

Answer

Sodium (Na+)

Answer

Potassium (K+)

Answer

Chloride (Cl-)

Question 6

The refractory period of cardiac muscle is important because it prevents:

Accepted Answer

Tetanic (sustained) contractions that would stop effective pumping

Answer

Atrial depolarization from occurring too rapidly

Answer

Blood from flowing backward through the semilunar valves

Answer

Action potentials from originating in the SA node

Question 7

Which component of the cardiac conduction system is responsible for delaying the electrical signal between the atria and ventricles?

Accepted Answer

Atrioventricular (AV) node

Answer

Sinoatrial (SA) node

Answer

Bundle of His

Answer

Purkinje fibers