Fetal pigs provide a good specimen for the study of physiological systems and processes due to the similarities between many pig and human organs. So, analyzing how the fetal pig exchanges oxygen and carbon dioxide will provide us information about the exchange of oxygen and carbon dioxide in the human body.
The respiratory system of the fetal big is responsible for this exchange. The exchange takes place in the alveoli (tiny air sacs of the lungs).
Inhaled oxygen enters the lungs and reaches the alveoli. Then it passes quickly through this air-blood barrier into the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.
To support the exchange of oxygen and carbon dioxide, enough amount of air per minute must be brought in and out of the lungs,