Hearts are muscular organs in the body that pump blood throughout the circulatory system. They are essential for delivering oxygen and nutrients to tissues while removing carbon dioxide and waste products. The human heart has four chambers: two atria and two ventricles, which work together to maintain blood flow. In addition to their biological function, hearts are often used symbolically in art and culture. The heart shape is commonly associated with love and affection, appearing in various forms such as Valentine's Day cards and romantic literature. This symbolism reflects the emotional significance attributed to the heart in many societies.