What are the functions of lungs?

Lungs perform several vital functions in the body:

1. Gas Exchange (Respiration):

- Lungs facilitate the exchange of oxygen and carbon dioxide between the body and the atmosphere.

- During inhalation, oxygen-rich air is drawn into the lungs.

- In the lungs, oxygen from the inhaled air moves into the bloodstream, while carbon dioxide, a waste product of metabolism, moves from the bloodstream into the air.

- This exchange occurs in the alveoli, tiny air sacs in the lungs where the exchange of gases takes place.

2. Filtration of Air:

- Lungs act as filters for inhaled air, preventing harmful substances from entering the bloodstream.

- The nasal passages, trachea, and bronchi contain mucus and cilia (hair-like structures), which trap dust, pollutants, and other particles from the air.

- These particles are then removed through coughing or sneezing.

3. Regulation of Blood pH:

- Lungs help regulate the pH balance of the blood by controlling the levels of carbon dioxide in the body.

- Carbon dioxide combines with water to form carbonic acid, which can affect the acidity or alkalinity of the blood.

- By adjusting the rate of exhalation, the lungs can influence the blood's pH, maintaining a stable acid-base balance.

4. Voice Production:

- The lungs provide the power for vocalization.

- When air is expelled from the lungs, it passes through the vocal cords in the larynx (voice box).

- The vibration of the vocal cords produces sound waves, which are further shaped and resonated by the vocal tract to produce human speech and sounds.

5. Production of Pulmonary Surfactant:

- The lungs produce pulmonary surfactant, a substance that reduces surface tension in the alveoli.

- Surfactant helps keep the alveoli open, preventing them from collapsing, especially during exhalation.

- It is crucial for maintaining proper lung function and preventing lung collapse.

6. Endocrine Function:

- The lungs also have an endocrine function, producing hormones that affect the cardiovascular system and immune responses.

- For example, the lungs produce atrial natriuretic peptide (ANP), which regulates blood volume and blood pressure.

In summary, lungs are vital organs responsible for gas exchange, filtration of air, regulation of blood pH, voice production, production of pulmonary surfactant, and endocrine functions. They play a central role in maintaining homeostasis and overall respiratory and circulatory health.