Final answer:
CO in medicine refers to Cardiac Output, which is the volume of blood each ventricle pumps per minute, typically averaging between 4-6 L/min for a resting adult and calculated with the formula CO = HR x SV. During exercise, this can rise significantly. Factors like heart size, physical condition, and environmental influences affect CO.
Step-by-step explanation:
In medicine, CO stands for Cardiac Output, which is the measurement of the blood volume pumped by each ventricle in one minute. The average cardiac output in a resting adult is typically within the range of 4-6 liters per minute (L/min), but the mean value can be approximately 5.25 L/min, reflecting the normal range from each ventricle separately. The common equation used to calculate cardiac output is represented by CO = HR x SV, where HR is heart rate, measured in beats per minute (bpm), and SV is stroke volume, the amount of blood pumped by a ventricle in a single beat, generally measured in milliliters (mL).
During exercise, the cardiac output can increase significantly. A healthy young individual's HR may rise up to 150 bpm, and their SV can increase from a resting 70 mL to about 130 mL, which can in turn lead to an increase in CO up to approximately 19.5 L/min. This is 4-5 times the resting rate, with elite athletes being able to reach even higher CO levels during peak performance.
Resting HR averages around 75 bpm, with a normal range between 60-100 bpm for some individuals. The normal range for SV is generally 55-100 mL. Factors such as the size of the heart, physical and mental condition, sex, contractility, duration of contraction, and preload and afterload, all play important roles in influencing these values.