In this deck, we'll explore the human gas-exchange system. You'll learn how your body takes in the oxygen it needs for respiration and gets rid of the waste product, carbon dioxide. We'll cover the structures involved, the process of breathing, and how gas exchange happens in the lungs.

For gases to move efficiently, exchange surfaces need special features. For your exam, you need to remember four key features: a large surface area, a thin surface for a short diffusion distance, a good blood supply, and ventilation to maintain concentration gradients.

Let's follow the path of air into the lungs. Air enters through the larynx, or voice box, and goes down the trachea, also known as the windpipe. The trachea then splits into two large tubes called bronchi, with one bronchus going to each lung.