This blood enters the <u>Right atrium</u>, <u>right ventricle</u> and then moves down. The presence of the <u>valves</u> prevents the backflow of blood inside the heart.
<u>EXPLANATION:</u>
The blood that contains water materials and is poor in oxygen content is brought by the blood vessels to the right atrium or the upper chamber of the heart.
The blood then moves via the tricuspid valves to the right ventricles or the lower chamber. The presence of valves prevents the blood from flowing back. The valves also control the amount of blood flow in the heart.
Altitude doesn't change uniformly because the four main layers of the atmosphere have different temperature gradients, creating the thermal structure of the atmosphere.
