Re: Why do frogs have three chamber hearts and what is its benefit?

Dear Kim,

Frogs contain a three chambered heart consisting of Two atria and one ventricle because there is a possibility of the oxygenated and unoxygenated blood mixing in the ventricle. Blood flows through a pulmonary circuit (to the lungs and skin) and a systemic circuit (to all other organs) in a scheme called double circulation.    

         Fish have a 2-chambered heart with one atrium and one ventricle. Blood pumped from the ventricle goes to the gills, where it is oxygenated.             

        Bird and mammals contain a four-chambered heart with two atria and two ventricles.

Double circulation is similar to that of amphibians except that oxygenated and deoxygenated blood does not mix due to possession of two ventricles. For more information on frogs go to the site:

"The somewhat amusing world of frogs"

Another excellent site is the Thousand Friends of Frogs from Hamline University in St.Paul Minnesota. Tt received the "Editor's Choice Award for its web site, it connects K-12 grade students, educators, families and scientists to study and celebrate frogs and their habitats.

http://cgee.hamline.edu/frogs/

Exploratorium includes online exhibits, activities and feature articles on frogs, they can be found at :

http://www.exploratorium.edu/frogs/

I hope the above links will give you more insight into the world of frogs. Thank you for taking the time to send in a question to the Mad Scientists.