Question

Cardiac output is

• A. the amount of air pumped by lungs per minute
• B. the amount of air pumped by lungs per second
• C. the amount of blood delivered by the heart to the aorta per minute
• D. the amount of blood delivered by the heart to the aorta per second

Hint:

Always look at the time unit in physiological definitions.
Cardiac Output is expressed per minute ($\text{L/min}$), whereas Stroke Volume is expressed per beat ($\text{mL/beat}$).

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the standard physiological definition of Cardiac Output (CO).

Step 2: Detailed Explanation:

• Cardiac Output is a crucial cardiovascular parameter that measures the functional capacity of the heart.

• It is defined as the volume of blood pumped by the left ventricle into the systemic circulation (via the aorta) per unit of time.

• The standard clinical unit of measurement for cardiac output is liters per minute ($\text{L/min}$).

• It can be calculated mathematically using the formula:
\[ \text{Cardiac Output (CO)} = \text{Stroke Volume (SV)} \times \text{Heart Rate (HR)} \] where Stroke Volume is the amount of blood pumped per beat, and Heart Rate is the number of beats per minute.

• Thus, Option (C) accurately captures both the anatomical pathway (heart to aorta) and the standard time frame (per minute).

Step 3: Final Answer:
Cardiac output is the amount of blood delivered by the heart to the aorta per minute.