Q.The heart has______________chambers

The circulatory system's job is transportation: it carries oxygenated blood from the heart out to the body's cells, and deoxygenated blood back to the heart, and then on to the lungs and back again — all powered by the heart and carried through arteries and veins.

The HEART itself has four parts: two pumping chambers (the ventricles) and two receiving chambers (the atria), with the two sides of the heart kept separate by a thick muscular wall called the septum. BLOOD VESSELS come in three kinds: veins (which bring deoxygenated blood from the cells back to the heart), arteries (which carry oxygenated blood from the heart out to the cells), and capillaries (the very thin vessels where the actual exchange of nutrients and oxygen with the tissues happens). BLOOD itself is the fluid doing the carrying — made of red blood cells, white blood cells, plasma and platelets, and coloured red by the pigment haemoglobin. …