Part 2: The skin is the largest organ in the body and the one we are probably most familiar with. It is right there before our eyes every day, but without the aid of a microscope we cannot really appreciate its complexity and many important functions.
Part 1: The cardiovascular system (the heart and blood vessels) is the most vitally important organ system in the body. Your heart pumps blood, and your blood vessels channel and deliver nutrient-rich oxygenated blood throughout your body.
Part 2: The cardiovascular system (the heart and blood vessels) is the most vitally important organ system in the body. Your heart pumps blood, and your blood vessels channel and deliver nutrient-rich oxygenated blood throughout your body.
Part 1: The human respiratory system—of which the lungs are the largest component—is the most high-tech air purification and conditioning system on earth.
