Final answer:
Cardiac output is the amount of blood pumped by each ventricle of the heart in one minute, calculated as the product of heart rate and stroke volume. It is a key factor in regulating blood pressure and can change with physical activity, strength of heart contractions, and blood volume returning to the heart.
Step-by-step explanation:
The value determined by multiplying the heart beat (or heart rate) by the volume of blood ejected with each contraction is called cardiac output. Cardiac output (CO) measures the amount of blood pumped by each ventricle in one minute. It is the product of the heart rate (HR), which is the number of contractions per minute, and the stroke volume (SV), which is the amount of blood ejected by the ventricle with each heartbeat.
The mathematical equation representing this is CO = HR × SV. An average resting adult has a cardiac output of about 5 to 6 liters of blood per minute, with each major pumping chamber of the heart ejecting around 70 mL of blood per contraction at a rate of 75 beats per minute.
The regulation of blood pressure is directly tied to cardiac output, as well as peripheral vascular resistance. Cardiac output can be increased by elevating the heart rate, as seen during exercise, or by increasing the stroke volume, which can occur if the heart contracts more forcefully. Factors affecting stroke volume include the speed of blood circulation through the body, the strength of heart contractions, and the amount of blood entering the heart between contractions.