The circulatory system of an amphibian is divided into two separate loops. The pulmonary circulation carries deoxygenated blood from the heart to the lungs and back to the heart. The systemic circulation carries oxygenated blood from the heart to the body and back to the heart. The three-chambered heart of an amphibian reflects the division of the circulatory system into pulmonary and system circulation. Deoxygenated blood from the body first enters the right side of the heart. Blood moves into the right atrium. Then oxygenated blood from the lungs enters the left atrium. Contraction of the atria forces the deoxygenated and oxygenated blood into the single ventricle, the main pumping chamber of the heart. Although the ventricle is not divided, its spongy interior surface and the coordinated contractions of the atria keep the oxygenated and deoxygenated blood from mixing. Ventricular contraction expels both kinds of blood into the conus arteriosus, which directs deoxygenated blood to the lungs and oxygenated blood to the body.

 

Explain how, in a three-chambered heart, the oxygenated blood is kept separate from the deoxygenated blood, even though both are pumped from the same ventricle.

 

 

How many atria are in an amphibian heart?

 

How many ventricles are in an amphibian heart?

 

How are amphibians able to mostly keep oxygenated and deoxygenated blood separated and prevent mixing in the ventricle?

Described the overall process of the cardiovascular system of the amphibian. Use the animation above, what is represented in blue and red?

 

How does the oxygenated blood flow from the lungs to the heart and the rest of the body?

 

How does the deoxygenated blood get removed from the rest of the body?

 

How does the double-loop circulation work?