Cardiac Output
Applied Science: BTEC Level 3 National Extended Diploma, topic 4.5.6
Calculating Cardiac Output
Cardiac output is the amount of blood that the heart pumps in a minute. It is essentially a measure of how hard the heart is working, and it can be calculated.
Cardiac output
- Cardiac output is a measure of how hard the heart is working.
- The amount of blood being pumped by the heart per minute is the cardiac output, and we can calculate it using heart rate and stroke volume.
- Heart rate is the number of beats per minute.
- Stroke volume is the volume of blood being pumped out by the left ventricle per beat.
Calculating cardiac output
- We calculate cardiac output using this equation:
- Cardiac output = beats per minute x stroke volume
- The higher the heart beat, and the higher the stroke volume, the higher the cardiac output.
Changes to cardiac output
- Cardiac output can change, and is controlled by the cardiac control centre in the medulla oblongata.
- Increasing heart rate or stroke volume enables oxygen to be delivered to tissues more rapidly, and waste products can be taken away more quickly.
- This is important in exercise.
Test yourself on Cardiac Output
Where in the brain is the cardiovascular control centre located?