Which factor is NOT a component of cardiac output?

Cardiac output is defined as the volume of blood the heart pumps per minute and is determined by two primary components: heart rate and stroke volume. Heart rate refers to the number of beats per minute, while stroke volume represents the volume of blood ejected by the heart with each contraction. Together, these factors can be multiplied to give the cardiac output.

End diastolic volume, which indicates the amount of blood in the ventricles just before contraction, is closely related to stroke volume and plays a crucial role in determining stroke volume through mechanisms such as the Frank-Starling law of the heart. Hence, it is important for understanding how efficiently the heart pumps.

Oxygen consumption, however, while related to the overall efficiency of the cardiovascular system and how well it supports metabolic activity, is not a direct component or determinant of cardiac output itself. While oxygen consumption can influence or indicate cardiac health and performance, it does not directly factor into the calculation of cardiac output, which is specifically focused on the heart’s pumping capacity through heart rate and stroke volume. This distinction clarifies why the correct answer is that oxygen consumption is not a component of cardiac output.