Bronchiectasis

Bronchiectasis can be broken down into “Bronchi” which refers to the bronchi and bronchiole airways of the lower lungs, and “-ectasis” means a dilation or expansion.

So in bronchiectasis chronic inflammation causes the bronchi and bronchioles to get damaged and dilated. Bronchiectasis is an obstructive lung disease, and that’s largely because the inflammation causes mucus plugs to form in the airways, and those mucus plugs obstruct airflow.

Normally, when taking a breath, the diaphragm muscle moves down and that creates negative pressure within the chest. This draws air in through the mouth or nose, and down the trachea.

Once there it goes into one of the primary bronchi or main bronchi, then secondary bronchi or lobar bronchus, then tertiary bronchi or segmental bronchus, and finally into the bronchioles which lead into the alveoli.

The alveoli is where the majority of gas exchange occurs in the lungs.

Taking a closer look at the airways, particularly the walls of the airways, they’ve got elastin fibers, which help give them their rubber-band like properties, and are lined with epithelial cells - some of which have brush-like projections, called cilia on their surface and others that secrete mucus.

The mucus traps foreign particles like bacteria and dust, and the mucus then gets swept upwards and out of the lungs by the cilia.

Together this whole system is called the mucociliary escalator.

Eventually that mucus and any stuck particles move into the esophagus and get swallowed and destroyed by the acid in the stomach! That’s right - you’re swallowing that mucus as you watch this.

Bronchiectasis results from diseases that cause chronic inflammation.

One cause of chronic inflammation is primary ciliary dyskinesia, where cilia don’t move normally and that leaves mucus stuck in the airways.