QS Study

To sustain life toad requires food and oxygen. Body cells cannot directly take the ingested food substances and oxygen from the air. So digested food substances and oxygen from air are required to reach each cell. Similarly, it is required to expel carbon-dioxide and other wastes from the body formed as a result of metabolism. The circulatory system of the toad is similar to humans but they have only one ventricle in their heart instead of two. The heart is a pump that carries deoxygenated blood to the lungs and oxygenated blood from the lungs to the rest of the body.


For this reason, an efficient transport system is built into the body of the animal. Blood and lymph work as internal transport media. Blood and lymph supply oxygen, hormone and digested food to the cells and help in egestion of excretory products of cells. This process is called circulation.

Since toads have only one ventricle, the blood flows from both atriums into one ventricle so it has both oxygenated and deoxygenated blood in it. The heart is specially made like this so that the toad has the ability to stay underwater longer.

The circulatory system is formed of blood, heart, blood vessels and lymph vessels.