this is the heart of a penguin. The penguin heart, just like yours and mine, is a muscle. Penguin hearts and mammal hearts are unique among animal hearts. We all have four chambers in our hearts. Basically, this means that oxygenated blood is always separated from poorly oxygenated (deoxygenated) blood. (This is considered an evolutionary advancement over reptiles, amphibians and fish.) These four chambers are the right and left atria and the right and left ventricles. The atria (singular: atrium) collect blood returning from the body or lungs and pump that blood into the ventricles. The ventricles have more important jobs; their either pump the blood throughout the penguin or to the lungs of the penguin so that it can be oxygenated. Since the left ventricle pumps blood throughout the penguin body, it is much stronger than the right ventricle which pumps blood to the lungs of the penguin only.
It might sound strange, but penguin hearts need blood as well, just like all other organs in the penguin. A penguin's heart is composed of cardiac muscle and it has its own blood supply: the cardiac arteries. As in humans, these can become clogged and be the source of heart attacks and death in penguins.
