Final answer:
CO2 and O2 exchanges occur in the alveoli of the lungs (external respiration) and in the tissues (internal respiration). Oxygen and carbon dioxide move according to pressure gradients, with oxygen being used by cells and producing carbon dioxide as a waste product. The respiratory and cardiovascular systems work together to transport these gases throughout the body.
Step-by-step explanation:
The exchange of CO2 and O2 happens twice in our bodies: firstly, in the lungs and secondly, at the tissues. This process is known as external and internal respiration, respectively. During external respiration, in the alveoli of the lungs, oxygen is picked up by the blood and carbon dioxide is released.
Oxygen and carbon dioxide flow according to pressure gradients from areas of high pressure to areas of low pressure. Oxygen diffuses across the alveoli into the bloodstream and is then transported to the tissues where it is utilized by cells, producing carbon dioxide as a waste product. This CO2 diffuses out of the blood and back into the alveoli to be expelled.
The transport of oxygen and the expulsion of carbon dioxide are vital processes for the maintenance of cellular respiration and the overall homeostasis of the body's pH levels. The levels of carbon dioxide in the blood are monitored closely; if they become too high or too low, our breathing rate will adjust to normalize these levels. Therefore, the transport of gases in the respiratory system is a crucial and continuous process, facilitated by both the respiratory and cardiovascular systems.