How does the body defend itself against harmful effects of airborne dust?

The human body has several defense mechanisms to protect itself against the harmful effects of airborne dust:

1. Mucus and Cilia: The respiratory tract is lined with a layer of mucus that traps dust particles. Tiny hair-like structures called cilia help move the mucus and trapped particles out of the airways through coughing and sneezing.

2. Nasal Hair: The nasal cavity has filters made up of fine hair that trap dust and other particles before they can enter the respiratory tract.

3. Alveolar Macrophages: These specialized immune cells reside in the air sacs (alveoli) of the lungs. They ingest and remove inhaled particles such as dust, bacteria, and pollutants.

4. Sneezing and Coughing: These reflexes help expel dust particles and other irritants from the respiratory system.

5. Bronchial Constriction: Exposure to excessive dust can cause the airways to narrow (bronchial constriction) to reduce dust inhalation.

6. Immunological Response: The immune system produces antibodies that specifically recognize and target foreign particles, including dust components. White blood cells can also engulf and destroy dust particles.

7. Mucus Production: Airborne dust can trigger an increase in mucus production, helping to trap and expel dust particles.

8. Inflammation and Repair: In response to dust exposure, the body may initiate inflammatory processes to remove damaged cells and promote tissue repair.

It's important to note that while these defense mechanisms are effective in most cases, excessive exposure to hazardous dust and pollutants can still cause adverse health effects, especially in individuals with respiratory conditions or weakened immune systems.