A frog's heart and skin breathing

In most adult frogs, the heart has two atria and one ventricle. Blood with higher and lower oxygen content enters the shared ventricle, but the streams can be partly separated by the heart’s anatomy and outflow tract; the degree of mixing varies among species and conditions. Frogs breathe through both lungs and moist skin. During submergence, some gas exchange can occur through the skin, while circulation and heart rate change depending on species, temperature, and dive duration.