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Structure and Function
Learning Tip Verbally describe photos or illustrations in this book to a real or imaginary friend who cannot see them. Provide all the details they need to accurately visualize what you are describing. Record your voice during this activity so that you can study, by listen- ing, while doing other things such as household chores or exercising.
Structure and Function
The main function of the cardiovascular system is to deliver oxygen-rich blood and nutrients to tissues and organs and to remove the waste products and carbon dioxide. This system includes a complex network of arteries, veins, capillaries, and the key structure—the heart—which pumps blood throughout your entire body. Cardi/o is the combining form for heart and vascul/o is the combining form for blood vessel . The Heart The heart is a hollow, muscular organ about the size of a closed fist that pumps oxygen-rich blood and nutrients to the trillions of cells of the body (Figure 6-1). To accomplish this, it beats an average of 60 to 100 times a minute throughout your entire lifetime. Your heart is in the center of your chest, slightly to the left,
Superior vena cava
Aorta
Left pulmonary artery
Right pulmonary artery
Right pulmonary veins
Left pulmonary veins
Pulmonary semilunar valve
RIGHT ATRIUM (RA)
LEFT ATRIUM (LA)
Tricuspid valve
Aortic semilunar valve
Mitral valve
RIGHT VENTRICLE (RV)
LEFT VENTRICLE (LV)
Inferior vena cava
Apex
Interventricular septum
Descending aorta
Oxygenated blood
Unoxygenated blood
FIGURE 6-1 The heart.
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