Human Body Quiz

The human body is an extraordinary biological machine, containing approximately 37 trillion cells organized into tissues, organs, and organ systems that work together to sustain life. The body maintains homeostasis - A stable internal environment - Despite constantly changing external conditions. Understanding how the body works is fundamental to medicine, nutrition, fitness, and personal health management. The study of the body is divided into anatomy (structure) and physiology (function).

Amazing Body Facts

The human body is full of remarkable statistics. The brain contains approximately 86 billion neurons with trillions of connections, making it the most complex object in the known universe. The human heart beats approximately 100,000 times per day, pumping about 5 liters of blood per minute through a network of vessels that, if stretched end to end, would circle Earth approximately 2.5 times. The lungs contain about 300 million alveoli, giving a total surface area roughly the size of a tennis court for gas exchange. The liver performs over 500 different functions. The small intestine, despite being called 'small,' is approximately 20 feet long and is responsible for absorbing nearly all the nutrients from food.

Learn more with our Anatomy Quiz or our Nervous System Quiz.