Bronchiectasis Flashcards
What happens when take a breath (diaphragm)
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.
What is the pathway of airflow?
(Main) Primary bronchus > (Lobar) Secondary bronchus > (Segmental) Tertiary bronchus > Alveoli (Gas exchange)
Components of Walls of the airways
- Elastin fibers (Rubber band like properties)
- Epithelial cells which have cilia
- Mucus (traps foreign particles)
- Mucociliary escalator
What is the definition of bronchiectasis?
Bronchiectasis is the permanent dilation of bronchi due to the destruction of the elastic and muscular components of the bronchial wall.
Epidemiology of bronchiectasis
- F>M
- Present at any age but increases with age
What is bronchiectasis a result of?
Disease that cause chronic inflammation
How does primary ciliary dyskinesia cause B?
cilia don’t move normally which leaves mucus stuck in the airways. Bacteria trapped in the mucus start to multiply and can cause a pneumonia. If that happens repeatedly, it results in chronic inflammation.
How does CF cause B?
mucus is sticky and therefore hard to sweep. The mucus accumulates and recurrent pneumonias lead to chronic inflammation
How does airways obstruction cause B?
e.g. tumour in the airway or outside of the airway or a foreign object that is lodged in the bronchioles.
The blockage prevents the mucociliary escalator from clearing out the mucus, and leads to recurrent pneumonias and chronic inflammation.
What post- infections can cause B?
- TB,
- measles,
- bronchiolitis,
- pneumonia,
- HIV
What infections worsen the problems?
aspergillosis can worsen the problem as they can cause a hypersensitivity response which results in further inflammation of the airways.
What happens overtime due to chronic inflammation?
immune cells and their cytokines can damage the ciliated epithelial cells and destroy the elastin fibres in the walls of the airway. The airways become dilated and clogged with mucus.
What type of lung disease is B?
obstructive lung disease, as the inflammation causes mucus plugs to form in the airways which can obstruct airflow.
What happens after the airways become clogged with mucus?
Fibroblasts move in to try and repair the damage by depositing collagen. The loss of elastin and the buildup of collagen, makes the lungs less elastic and more stiff. The stiff, mucus-filled lungs make it tough for air to flow smoothly.
The inflammation can also extend to involve the pleura.
What happens overtime as lung function declines?
Hypoxia
