that blood first enters. Aventricleis one of the two muscular V-shaped chambers that
pump blood out of the heart. The four chambers of the heart are shown inFigure18.11.
The atria receive the blood, and the ventricles pump the blood out of the heart. Each of the
four chambers of the heart have a specific job, these are:
- The right atrium receives oxygen-poor blood from the body.
- The right ventricle pumps oxygen-poor blood toward the lungs.
- The left atrium receives oxygen-rich blood from the lungs.
- The left ventricle pumps oxygen-rich blood out of the heart to the rest of the body.
The heart is usually found in the left to middle of the chest with the largest part of the heart
slightly to the left. The heart is usually felt to be on the left side because the left ventricle
is bigger and stronger than the right ventricle. The heart is surrounded by the lungs.
Figure 18.11: The atria receive blood and the ventricles pump blood out of the heart. ( 18 )Blood Flow Through the Heart
Blood flows through the heart in two separate loops; you could think of them as a “left side
loop” and a “right side loop”. Theright sideandleft sideof the heart refer to your heart as
it sits inside your chest. Its left side is your left side and, its right side is your right side.
The right side of the heart collects deoxygenated blood from the body and pumps it into
the lungs where it releases carbon dioxide and picks up oxygen. The left-side carries the
oxygenated blood back from the lungs, into the left side of the heart which then pumps the
oxygenated blood throughout the rest of the body.