Smart Doctor on Instagram: "The Inner Machine | Exploring Human Systems 🔬 . . . . . . . . . . . . The human heart is a vital organ that pumps blood throughout the body, supplying oxygen and nutrients while removing carbon dioxide and waste products. Here are some key points about the human heart: Anatomy: The heart has four chambers: two upper atria and two lower ventricles. The right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the rest of the body.