👉 The double fluid, also known as the "double blood" or "doubled circulation," is a physiological concept describing a unique circulatory system found in certain vertebrates, most notably amphibians and some fish. In this system, blood is divided into two distinct streams: one that circulates through the heart and lungs (the pulmonary circulation) and another that bypasses these organs, directly supplying tissues and organs with oxygenated blood (the systemic circulation). This dual pathway allows for more efficient oxygen and nutrient delivery to tissues, especially in environments where oxygen availability might be limited or where rapid exchange is crucial. The double fluid system enhances survival by optimizing the body's ability to meet metabolic demands under varying conditions.
