EVERYDAY SCIENCE

Detailed explanation-1: -Oxygen-poor blood returns from the body to the heart through the superior vena cava (SVC) and inferior vena cava (IVC), the two main veins that bring blood back to the heart. The oxygen-poor blood enters the right atrium (RA), or the right upper chamber of the heart.

Detailed explanation-2: -Blood first enters the heart’s right atrium. A muscle contraction forces the blood through the tricuspid valve into the right ventricle. When the right ventricle contracts, blood is forced through the pulmonary semilunar valve into the pulmonary artery.

Detailed explanation-3: -The right atrium is the first chamber of the heart that the blood comes into contact with as it returns from the systemic circulation, and from the blood supply to the heart.

Detailed explanation-4: -There are two atria (upper chambers) called your right atrium and left atrium. In addition, there are two ventricles (lower chambers) called your right ventricle and left ventricle.

Detailed explanation-5: -Right atrium: Receives blood returning to the heart from the superior and inferior vena cava; transmits blood to the right ventricle, which pumps blood to the lungs for oxygenation.