Question

Describe the process of gaseous exchange in the lungs with 200-300 words.

Answer 1

Gas exchange is the process of exchange of oxygen from inhaled air and carbon dioxide from the body.

Gas exchange occurs in two ways that are pulmonary exchange and tissue level gas exchange. Pulmonary gas exchange is also called external respiration. This exchange occurs in the respiratory membrane of the lung. There is present of alveoli in the lung. Exchange of gas occurs in the alveolar wall and tiny capillaries which are surround the alveolar wall. The inhaled air with a high amount of oxygen gets diffuse to the capillaries because the blood in the venous has a low partial pressure of oxygen and a high partial pressure of carbon dioxide. The inhaled air have low pressure of carbon dioxide as compared to the partial pressure of carbon dioxide in the bloodstream. So the carbon dioxide get diffuse from the bloodstream to the alveoli and remove from the body during exhalation. Remember that the gas always will diffuse from higher concentration to lower concentration. The oxygen which diffuses to the bloodstream or oxygenated blood is transported to the heart and again heart transported the oxygenated blood to whole body. This oxygen is absorbed or used by the cells of the body and produce carbon dioxide. This carbon dioxide diffuse to the blood vessel from the tissues leads to deoxygenated blood in the veins. This process is called internal respiration or tissue level gas exchange. The deoxygenated blood is transported to the heart and then from heart to the lung for purification. So gas exchange are occur in circular motion.