During chronic bronchitis, the bronchi commonly lose appendages called , which function to cleanse the respiratory passages.

During chronic bronchitis, the bronchi commonly lose appendages called cilia. These tiny, hair-like structures line the bronchial tubes and function to cleanse the respiratory passages. They do this by moving in coordinated, wave-like motions to push mucus and trapped particles up and out of the respiratory tract, helping to prevent infection and damage.

Here are the steps of how this happens:

1. The cilia beat in a coordinated, rhythmic motion, which moves mucus and trapped particles upwards towards the throat.
2. This mucus-trap is then either coughed out or swallowed, effectively removing the potential harmful substances from the respiratory system.
3. In chronic bronchitis, however, the cilia become damaged and lose their ability to effectively move mucus and trapped particles. This can lead to a buildup of mucus, which can cause further inflammation and infection in the bronchi.
4. Over time, the bronchi may lose cilia entirely, further impairing the body's ability to cleanse the respiratory passages. This can lead to a cycle of inflammation, mucus production, and infection that characterizes chronic bronchitis.