A<unk>  is a cardiac<unk>  which allows blood to flow from the<unk>  heart to the<unk>  heart. This terminology is used both for the abnormal state in humans and for normal physiological<unk> s in reptiles.
Right-to-left shunt
Pulmonary-to-systemic shunt
Pulmonary shunt
Cardiac shunt
Ventilation perfusion mismatch
Bio-secure bubble
Alveolar–arterial gradient
Hypoxic pulmonary vasoconstriction