The human heart has four chambers: two ventricles, each of which is a muscular chamber that squeezes blood out of the heart and into the blood vessels, and two atria, each of which is a muscular chamber that drains and then squeezes blood into the ventricles. The two atria reside at the top of the heart; the two ventricles are at the bottom. And, the heart is divided into left and right halves, so there is a left atrium and left ventricle, as well as a right atrium and right ventricle.
<span>The reason that the heart is divided into halves is because of the two-circuit circulatory system. The right side of the heart can pump blood to the lungs, while the left side of the heart pumps blood to the rest of the body. Blood goes in both directions on each and every pump.</span>Human hearts, as well as the hearts and circulatory systems of some other mammals, are complex. They need to have a higher blood pressure to get the blood circulated throughout their entire bodies. Blood pressure is a force that sends the blood through the circulatory system.
Exposure to radiation and other environmental mutagens.
We know that in one day there is 24 hours. We split 24 hours into 3 parts because the denominator is 3. It says that 2/3 was asleep. I know 1/3 is 8 hours so Peter spent 16 hours sleeping. 24-16 is 8.
<u>Peter the dog was awake for 8 hours a day</u>.
Answer: the heart, the blood vessel, and the blood itself
Explanation: hope this helps
