This weeks lecture we learned how the respiratory system works. Carbon dioxide and oxygen are exchanged between alveoli & capillaries. The alveoli is tiny air sacs in the lungs through whose walls gases such as oxygen and carbon dioxide diffuse in and out of the blood. We also learned that the lungs expand and contract about 12–20 times a minute. This is important and compares to this video because it elaborates on the respiratory system. In order to stay alive, the body has to in air. We breath in oxygen and breath out carbon dioxide. During the process of Respiration, breathing happens automatically. Everyday the body breaths out 20,000 breaths. A fun fact that I learned from this video is that by 70 years old, we have reached about 600 million breaths. During the respiratory system, all breathing occurs, through our nose, throat, voice box, windpipe, and lungs. When we exercise the body needs more oxygen to feed the muscles. As we work harder, the body responds by breathing more quickly and deeply. This video was very informative and elaborated on what we learned about the respiratory system this week.