Final answer:
Cardiac output is the volume of blood pumped by the heart per minute, calculated as the product of heart rate and stroke volume. Answer A) Stroke volume × heart rate is correct. Factors such as sympathetic stimulation and thyroid hormones can affect cardiac output.
Step-by-step explanation:
Cardiac output is defined as the volume of blood pumped by the heart in one minute. It is calculated by multiplying the heart rate (HR) by the stroke volume (SV), which is the volume of blood pumped by the ventricle with each heartbeat. Therefore, the correct answer to the question is A) Stroke volume × heart rate.
Factors that can affect cardiac output include sympathetic stimulation, thyroid hormones, and varying levels of ions in the blood. A high cardiac output increases blood pressure and promotes blood flow, while a low cardiac output can lead to decreased arterial pressure and blood flow.