What bodily mechanism helps prevent asbestos fibers from entering the lungs?

Cilia play a crucial role in the respiratory system by contributing to the body's defense against inhaled particles, including asbestos fibers. These tiny, hair-like structures line the respiratory tract and function by beating in a coordinated manner to move mucus, along with trapped particles and pathogens, upward towards the throat. This mechanism helps to prevent harmful substances from reaching the lungs, allowing for them to be expelled or swallowed.

When asbestos fibers are inhaled, they can become trapped in the mucus lining of the airways. Cilia then work effectively to transport this mucus, along with any embedded fibers, out of the lungs. The action of cilia is essential in maintaining respiratory health and reducing the risk of asbestos-related diseases.

Mucus plays a supportive role by trapping particles, while alveoli are involved in gas exchange but do not prevent particle entry. Macrophages are immune cells that help to digest and remove inhaled particles, but they do so after the particles have already entered the lungs, rather than preventing their entry in the first place.