The atria form the smaller part of the heart, while the ventricles form the larger part of the heart.
the atria
atria
The left ventricle forms the apex of the heart.
heart
smaller, smallest
The smaller part of the cell
smaller
The cadiovascular system, sometimes called the circulatory system when it includes the lymphatic system.
It is capitalized at the beginning of the sentence or when it forms part of the proper noun. Examples: Autumn in my Heart The Autumn (by Elizabeth Barrett Browning)
Yes, exactly. The blood must be next to every cell in the body. To do this it must branch over and over getting smaller and smaller until it forms tiny capillaries. The reverse is true as the blood goes back to the heart and lungs to pick up oxygen again.
the most anterior part of the simple tubular heart of lower vertebrates and embryos of higher vertebrates, leading into the artery that leaves the heart; in mammals it forms a part of the upper wall of the right ventricle, in which the pulmonary artery originates.
You have an aorta, which comes out from the heart. This comes down to your lower abdomen. It gives branches on the way to your head and brain, to your upper limbs, to various abdominal organs. Now it has to divide to two legs. That only means that you need smaller branches to various parts of the body. You have smaller and smaller arteries to reach every part of your body. No body probably knows about, how they go to each and every part of the body to supply the blood.