Cardiovascular System of a Parrot

Parrot is the common name of any species that is part of the order Psittaciformes, often native to tropical and subtropical rainforests. Like mammals and other bird species, parrots are warm-blooded or homeothermic and have a four-chambered heart, which works as two separate pumps that are responsible for the circulation of blood. In addition to the heart, blood vessels are also part of the cardiovascular system of a parrot.

  1. Heart

    • Parrots have large hearts, which are necessary to provide a high blood demand to the muscles during the flight and meet the high metabolic demands of flight. Their hearts have four chambers, two atria and two ventricles. Only oxygenated blood circulates in the left atrium and ventricle, while the right chambers always pump de-oxygenated or carbon dioxide-rich blood. The left ventricle is the largest and most muscular of all chambers because it pumps oxygenated blood to all parts of the parrot's body.

    Vessels

    • Arteries, veins and capillaries are the main blood vessels of parrots and other birds. Arteries are responsible for carrying blood away from the heart while veins take the blood back to the heart chambers. Small arteries distribute oxygenated blood to organs and tissues, while small veins collect carbon dioxide-rich blood. Capillaries are the thinnest vessels and are responsible for the exchange of gases, nutrients and other substances between the blood and the cells.

    Circulation Circles

    • Two circles form the circulation of parrots. The big circle of the circulation, also called corporal, begins in the left ventricle going to all cells of the parrot. After distributing oxygen to the cells and collecting carbon dioxide, the blood returns to the right atrium, concluding the big circle. The blood than goes to the right ventricle is pumped to the lungs, starting the small or pulmonary circle. In the lungs, carbon dioxide is swapped with oxygen, then the blood returns to the left atrium and goes to the left ventricle, where the big circulation starts again.

    Blood

    • The blood of a parrot contains cells and plasma, which is made mainly of water, plus proteins and other nutrients. Blood cells include erythrocytes or red blood cells, leukocytes or white blood cells and thrombocytes, small cells involved in the healing of tissues. Unlike mammals, parrots and other birds have nucleated and elliptical red cells. Red blood cells contain hemoglobin, which transports oxygen to all cells during the circulation, while white blood cells are responsible for immune-defense.