Question

Why does human have a four chambered heart?

Answer 1

We have 4 chambered hearts because we inherited it from the common ancestor of all mammals. Since mammals are endotherms, they generate a lot of Internal body heat to stay warm. To do so, we have to burn a lot of calories, which require a lot of oxygen. The 4 chambered heart is more effective than the 3 chambered hearts of our reptilian ancestors in maximizing the delivery of oxygen to all parts of the body. That is because the 4 chambered heart prevents the mixing of oxygenated blood from the lung and deoxygenated blood from the body. Some mixing of these types of blood occurs in animals with 3 chambered hearts, so that they have reduced ability to exercise aerobically. Humans, because we have a 4 chambered heart, are able to exercise for longer periods of time than reptiles before we are exhausted.

Answer 2

Answer:

The human heart is 4 chambered because They need to do the following jobs

Explanation:

The heart has four chambers: two atria and two ventricles.

The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle.

The right ventricle pumps the oxygen-poor blood to the lungs.

The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle.

The left ventricle pumps the oxygen-rich blood to the body.