Question

How do lungs function as excretory organs?

Answer 1

Hint: Lungs are the chief respiratory organ of our body. We breathe in oxygen and give out carbon dioxide through lungs. The lungs play an important role in oxygenation of blood.

Complete answer:
The excretion is the process of removal of waste from our body. The waste can be in the form of nitrogenous waste like urea, water, salt, some worn out cells, toxins, certain gases, bile etc.

The kidney is the chief excretory organ in our body which eliminates urea and excess water and salts in the form of urine.

The skin also serves as an excretory organ which excretes salt and water through sweat.
The liver and intestine excrete bile.
Another important excretory organ of our body is the lungs. It helps in eliminating the gaseous waste like carbon dioxide which is useless and harmful for our body. The chief function of lungs is respiration. We inhale oxygen which is essential for breaking down of glucose and generate energy required for the body.

The water and carbon dioxide which is not useful for the body is excreted in the form of air we exhale out.
Thus lungs play a vital role as both respiratory and excretory function.

Note: The gaseous exchange mechanism takes place at the alveoli of the lungs. The lungs also play a vital role in the gaseous exchange between the blood and the tissues. The oxygen inhaled is supplied to all the parts of the body via. blood which contains haemoglobin that act as a carrier of oxygen.