How does smoking impact the protective features of the respiratory system?

Smoking damages the protective features of the respiratory system by impairing cilia function and causing inflammation and cell damage.

The respiratory system has several protective features designed to keep harmful substances out and to expel them if they do get in. One of these features is the cilia, tiny hair-like structures that line the respiratory tract. The cilia move in coordinated waves to push mucus and trapped particles out of the lungs. However, the chemicals in cigarette smoke paralyse and eventually destroy these cilia, reducing their ability to clear mucus and increasing the risk of infection.

Another protective feature of the respiratory system is the layer of mucus that lines the respiratory tract. This mucus traps particles and bacteria, preventing them from reaching the lungs. However, smoking dries out this mucus, making it less effective at trapping harmful substances. Furthermore, the chemicals in cigarette smoke can cause inflammation and damage to the cells that produce this mucus, further reducing its effectiveness.

Smoking also damages the alveoli, the tiny air sacs in the lungs where oxygen is exchanged for carbon dioxide. The chemicals in cigarette smoke cause the walls of the alveoli to break down, reducing their surface area and making it harder for oxygen to be absorbed into the bloodstream. This damage is irreversible and can lead to chronic obstructive pulmonary disease (COPD), a serious and often fatal lung condition.

Finally, smoking impairs the immune response in the lungs. The chemicals in cigarette smoke can kill immune cells or impair their function, making it harder for the body to fight off infections. This, combined with the damage to the cilia and mucus, increases the risk of respiratory infections, including pneumonia and bronchitis.

In summary, smoking has a profound and damaging impact on the protective features of the respiratory system, increasing the risk of infection and serious lung diseases.