About Lung Diseases

HOW OUR BREATHING SYSTEM WORKS AND HOW DISEASE AFFECTS IT

What is in the Breathing System

Download a print friendly version of this page

The respiratory system includes the lungs and all the airways in the body. As we breathe, air moves in and out of the lungs through a system of connecting tubes or airways. The tubes are like an upside down tree. Air moves in through the windpipe TRACHEA then divides into smaller and smaller branches called bronchi and BRONCHIOLES. At the end of the airways are tiny air sacs called ALVEOLI that are covered with blood vessels. These blood vessels allow oxygen to get into the blood and waste products like carbon dioxide to be removed.

Other parts of this system include your NOSE which acts like a filter, your cough which removes anything that gets past your nose and CILIA which are tiny hair-like fibres that line the airways and work like a conveyor belt to carry phlegm upwards to shift any debris.

Breathing in occurs when the ribs move out and DIAPHRAGM moves down, expanding the chest space which then draws the air into the airways.
Breathing out occurs as the chest cavity contracts again and the waste air is pushed out into the airways.

ABOUT LUNG DISEASE

COPD You may have heard the term COPD (Chronic Obstructive Pulmonary Disease) or CAL (Chronic Airways Limitation) used by your doctor or while you were in hospital. The primary cause of it is cigarette smoking or exposure to second hand smoke. It is an umbrella term that can be used to describe chronic bronchitis, emphysema or a combination of both.

Chronic Bronchitis

This means long standing inflammation of the airways.
This causes excessive mucus to be produced.
The airways can also become narrow and floppy, making it harder to get air in and out, therefore causing breathlessness.

Emphysema

The tiny air sacs have been gradually destroyed.
This makes it harder for enough oxygen to get into your blood.
The airways walls become floppy and can collapse making it harder to get air in and especially out of the air sacs.

Bronchiectasis

With bronchiectasis there is a regular production of large amounts of sputum.
Usually caused by multiple infections.
The airways become thin and the cilia lining the airways do not work effectively to transport the phlegm up and out.

Asthma

This causes swelling of the inner lining of smallairways.
This in turn narrows the airways and causes spasm ofthe muscles around the airway and extra mucous.
It is largely related to allergies and reaction to air borntriggers.
These asthma changes can be fully reversed with medication.

COPD and Asthma People with COPD can have a component of Asthma which may allow partial but not full reversal of airway narrowing.

Pulmonary Fibrosis

This is caused by scarring to the actual lung tissue.
The lungs become stiff and this makes it harder to absorb oxygen.