Which of the following factors influences blood pressure?

Blood pressure is determined by several physiological factors, two of the most significant being cardiac output and peripheral resistance. Cardiac output refers to the volume of blood the heart pumps per minute, while peripheral resistance is the resistance to blood flow in the blood vessels, primarily influenced by the diameter of the arteries and arterioles.

When cardiac output increases, more blood is pumped into the circulation, which can elevate blood pressure. Conversely, if peripheral resistance increases due to factors such as constricted blood vessels, blood pressure will also rise as the heart works harder to pump blood through narrower pathways. Together, these factors directly affect the amount of pressure exerted on artery walls, making them central to understanding changes in blood pressure readings.

Other choices may touch on aspects that can influence blood pressure indirectly or are part of broader health considerations, but the direct and immediate factors that govern blood pressure regulation are primarily cardiac output and peripheral resistance. Thus, selecting this option encompasses the essential physiological mechanisms involved in blood pressure dynamics.