The circulatory system distributes the heat of muscle contraction in birds & mammals.

Question

Is the anatomy of birds & mammals conducive to maintaining a warm internal temperature?

Answer 1

The anatomy of the heart is the key to finding the answer for this question Birds and mammals have 4 chambered hearts left and right atria at the top and left an right ventricles at the bottom, separating the atria and ventricles a single wall of muscle called a septum.

From the body deoxygenated blood is pumped through a one way valve to right atrium, down through the right ventricle, passing through pulmonary arteries leading to the lungs that expell carbon dioxide and taken oxygen rich air. On the inhale the oxygenated blood travels via pulmonary veins to the left atrium, the left ventricle and a the main artery in the body the aorta that lead blood to the rest of the body.

Arteries pump deoxygenated blood AWAY from the heart.

Veins pump oxygenated blood to the the heart.

The four chamber heart's ability to keep deoxygenated blood separate from deoxygenated blood means an ample supply of oxygen that can convert glucose into stored fuel ( ATP ADENOSINE TRIPHOSPHATE) for needed muscle movement , and oxygen that can also remove lactic acid that accumulated in the muscle from activity.

ATP is the fuel for muscles ( it's warmth and movement) and is derived from glucose in the blood being converted into well oxygenated blood.