Physiology of Finfish and Shellfish (2+1)

2.2.7. Cardiac output

The volume of blood pumped by the heart per unit time is usually called the cardiac output or the cardiac minute volume. The cardiac output can be determined in a member of different ways. One commonly used method is known as fick and principle. If depends on the simple fact that all the oxygen consumed (10₂) by the animal is carried by the blood ejected from the heart. Therefore, if we know the difference on the oxygen content of arterial and various blood, we can calculate cardiac output (Qh) from the following equation.

VO₂ = Qh (CaO₂ – CVO₂)

To determine the cardiac output we can determine

1. The oxygen consumption
2. The oxygen consumption in arterial blood
3. Oxygen content in various blood

An arterial blood sample can be obtained from any artony, but the venous blood must be obtained as mind venous blood from the right side of the heart or from the pulmonary artery.