Which components make up stroke volume?

The correct answer identifies that stroke volume is primarily influenced by preload, afterload, and contractility.

Preload refers to the amount of blood that fills the ventricles of the heart at the end of diastole, which directly affects the stretching of cardiac muscle fibers, influencing the force of contraction during systole. A higher preload generally leads to an increased stroke volume due to the Frank-Starling mechanism.

Afterload is the resistance the heart must overcome to eject blood during systole. A higher afterload can decrease stroke volume because the heart has to work harder to pump against this resistance, which can lead to decreased cardiac output if the heart can't compensate.

Contractility represents the intrinsic ability of the heart muscle to contract. When contractility is strong, the heart can eject a larger volume of blood with each beat, positively influencing stroke volume.

Together, these three components provide a comprehensive understanding of how the heart pumps blood and how various physiological factors can influence cardiac performance. This framework is essential for a burn nurse, as understanding stroke volume can impact fluid resuscitation and management strategies for burn patients.