What determines the amount of blood that leaves the arterial system?

The amount of blood that leaves the arterial system is primarily determined by arterial pressure and total peripheral resistance. Arterial pressure refers to the pressure exerted by circulating blood upon the walls of blood vessels, which is crucial for facilitating blood flow throughout the body. When arterial pressure is high, it promotes a greater volume of blood to flow from the arterial system into the capillaries and surrounding tissues.

Total peripheral resistance, on the other hand, is the resistance faced by blood as it travels through the circulatory system. This resistance can be influenced by various factors, including the diameter of the blood vessels and the viscosity of the blood. If total peripheral resistance is low, blood can easily flow through the vessels, allowing more blood to exit the arterial system. Conversely, if resistance is high—such as during vasoconstriction—less blood will flow out.

The interplay between arterial pressure and total peripheral resistance is fundamental in controlling blood flow, making option B the most accurate in determining how much blood leaves the arterial system. Other choices, while related to cardiovascular physiology, do not directly encapsulate the primary factors involved in this specific mechanism.