CIRCULATORY - RESPIRATORY

- Alveolus is the principal structure in the gas exchange between the circulatory system and respiratory system (O2 and CO2).

- The alveoli are in charge of collecting all the oxygen that are present in the lungs and put it into the capillaries so that the oxygenated blood is distribute around all the body. The CO2 is taken by the alveoli and give it to the lungs so that it is expelled. To perform this function, the alveoli have to be wet and have pores to led the air in and out (image).

- If the alveoli do not work properly, then the gas exchange could not happen, leading to a non-oxygenated blood.