Trachea and lungs Small 276×320 Medium 553×640 Large 884×1024 Download TIFF Original 2073×2400 | (1.3 MB) Description "The trachea has in its walls stiff rings of cartilage that hold it open so that the air can pass freely through it to and from the lungs. At its base the trachea divides and sends a great branch to each lung." — Ritchie, 1918 Keywords anatomy, cartilage, lung, respiration, trachea Galleries Human Lower Respiratory System Source: John W. Ritchie Primer of Physiology (New York: World Book Company, 1918) 55
