Question

What is the principle of Exchange of gases?

Answer 1

Hint: The process of respiration involves both ventilation and perfusion thereby resulting in gaseous exchange.

Complete Answer:

- The basic process through which the gaseous gets exchanged during respiration is known as diffusion. This process aids in transport of gaseous in accordance with their concentration gradient. 

- The molecules of a gas move from a concentration of high gradient to a concentration of low gradient and this is known as diffusion. 

- Blood that is low in concentration of oxygen but high in carbon dioxide undergoes the process of gaseous exchange with air via lungs. This air present in the lungs shows a higher oxygen concentration than that of the oxygen-depleted blood present. 

- However, the concentration of the carbon dioxide gas here remains low. This concentration gradient facilitates the process of gaseous exchange during the process of respiration.  

There are two major mechanisms involved in breathing. They are:

1) Inspiration:

- The process by which air is inhaled is known as inspiration.

- It occurs when diaphragm and intercostal muscles contract. 

- Further, the chest cavity expands, producing a partial vacuum which then sucks air into the lungs and fills the expanded alveoli.

2) Expiration:

- The process by which air is exhaled is known as expiration.

- It occurs when diaphragm and intercostal muscles relax which leads to decrease in the chest cavity volume increasing the pressure of the lungs pushing the air out of the nose.

Therefore, “Diffusion” is the principle of exchange of gases.

Note: The rate of gaseous diffusion is proportional to the partial pressure existing in the total gas mixture. The breathing rate of an adult is around 15-18 times per minute.