Does anyone have any information on the Circulatory System of a Frog?

Question

Can I have a little bit of information on the frogs circulatory system? It would be most appreciated if someone had some information into WHY a frog has a 3-chambered heart (if there is a reason). Sorry I originally posted this in Homework Help but no answer for 40 minutes :( Can anyone here help?

Answer 1

The frog heart has 3 chambers: two atria and a single ventricle.

    * The atrium receives deoxygenated blood from the blood vessels (veins) that drain the various organs of the body.

    * The left atrium receives oxygenated blood from the lungs and skin (which also serves as a gas exchange organ in most amphibians).

    * Both atria empty into the single ventricle.

    * While this might appear to waste the opportunity to keep oxygenated and deoxygenated bloods separate, the ventricle is divided into narrow chambers that reduce the mixing of the two blood.

    * So when the ventricle contracts,

          o oxygenated blood from the left atrium is sent, relatively pure, into the carotid arteries taking blood to the head (and brain);

          o deoxygenated blood from the right atrium is sent, relatively pure, to the pulmocutaneous arteries taking blood to the skin and lungs where fresh oxygen can be picked up.

          o Only the blood passing into the aortic arches has been thoroughly mixed, but even so it contains enough oxygen to supply the needs of the rest of the body.

having more chambers allows more blood to be pumped in a single pump, so instead of simply pumping faster, they pump more, faster.

Answer 2

Frogs are known for their three-chambered heart, which they share with all tetrapods except birds and mammals. In the three-chambered heart, oxygenated blood from the lungs and de-oxygenated blood from the respiring tissues enter by separate atria, and are directed via a spiral valve to the appropriate vessel—aorta for oxygenated blood and pulmonary vein for deoxygenated blood. This special structure is essential to *****keeping the mixing of the two types of blood to a minimum, which enables frogs to have higher metabolic rates, and to be more active than otherwise.