Question

Define each of the three variables, and describe the factors that influence each one and how it affects stroke volume.

Answer 1

Factors affecting stroke volume and cardiac output are preload, contractility, and afterload.

Step-by-step explanation:

Factors Affecting Stroke Volume and Cardiac Output

Stroke volume (SV) is influenced by several factors including preload, contractility, and afterload. Preload refers to the volume of blood in the ventricles before contraction, which is influenced by factors such as venous return and blood volume. Contractility refers to the force of ventricular contraction, which is influenced by factors such as sympathetic stimulation and inotropic agents. Afterload refers to the resistance the ventricles must overcome to eject blood, which is influenced by factors such as arterial blood pressure and vascular resistance.

• Preload: The stretching of the ventricles before contraction. It is influenced by factors such as venous return and blood volume.
• Contractility: The force or strength of the ventricular contraction. It is influenced by factors such as sympathetic stimulation.
• Afterload: The resistance the ventricles must overcome to eject blood. It is influenced by factors such as arterial blood pressure and vascular resistance.