Protecting the Breathing System
The human breathing system is exposed to the external environment and is therefore at risk of damage from dust, microorganisms, pollutants, and other harmful particles. To keep the lungs healthy and functioning efficiently, the body has several protective features.
1. Mucus Production
The lining of the trachea, bronchi, and bronchioles contains goblet cells that produce mucus.
Mucus is sticky and traps dust, dirt, pathogens, and other foreign particles before they can reach the lungs.
2. Ciliated Cells
These are specialized cells with tiny hair-like structures called cilia.
Cilia beat in a wave-like motion to move mucus (along with trapped particles) upwards towards the throat.
The mucus is then either coughed out or swallowed, preventing harmful particles from entering the lungs.
3. Nasal Hairs
The nose is lined with coarse hairs that trap larger particles (e.g. dust or pollen) from entering the respiratory system.
4. Epiglottis
A small flap of tissue called the epiglottis sits at the top of the trachea.
It closes over the windpipe during swallowing to prevent food and liquid from entering the lungs.
5. Reflex Actions (Coughing and Sneezing)
If irritants like dust or smoke enter the breathing system, they trigger reflexes such as coughing or sneezing.
These actions help to quickly remove foreign particles from the airways.
6. Importance of Clean Air
Avoiding exposure to pollution, smoking, and harmful chemicals helps protect the lungs.
Wearing masks or working in well-ventilated areas reduces the risk of inhaling dangerous particles.
