KNOW YOUR BODY: How normal lungs function

Lungs are located in the chest, with one lung on the left and the other on the right side. Lungs are soft and usually protected by the ribcage. Each lung is made of sections referred to as lobes.

The function of the lungs is to bring in oxygen, which provides the body with energy besides getting rid of carbon dioxide, which is a waste product.


For the body to get needed oxygen, you inhale air through mouth or nose, though the nose is the preferred route since it filters air better.

Breathing through the nose lowers the quantity of irritants entering the lungs, and at the same time warms and moisturises the inhaled air.

When you require large quantities of air, you can breath in through the mouth, especially during exercise.

After the air enters the mouth or nose, it moves down the trachea. The trachea then divides into breathing tubes which continue to separate into smaller tubes known as bronchioles. Bronchioles then end into small air sacs known as alveoli.

There are several different muscles that aid breathing, with the largest and most efficient one being the diaphragm. It lies below the lungs and separates them from organs beneath, such as the stomach.

When the diaphragm compresses, the ribs flare out, the lungs enlarge and air gets drawn in, a process known as inhalation.

When the diaphragm relaxes, air is expelled from the lungs, and they return to their normal position, a process known as exhalation. Other muscles involved in breathing are located between the ribs and neck, for example the scalene muscle.

Sometimes, the diaphragm can be pushed down by certain conditions, hence it does not function properly. This makes other involved muscles to work harder, since they are not as effective as the diaphragm muscle. This can cause shortness of breath.


Lungs can be very vulnerable to irritants such as dust, however, there are several ways in which the lungs protect themselves from irritants

First, when breathing in, the nose filters the air to prevent large pieces of contaminants from getting into the lungs. When an irritant gets into the lung, it gets stuck in the mucous layer that lines the breathing tubes.

The mucous secreted by the breathing tubes is carried to the mouth by tiny hairs known as cilia, lining the breathing tubes.

Cilia carry mucus from the lungs up to the throat and to the epiglottis, the entry that allows mucus to be swallowed. This normally takes place involuntarily.

Usually, spitting out sputum does not happen except when a person has an infection like pneumonia or chronic bronchitis. Cough is another mechanism that lungs use to protect themselves. Coughing is normal, but it can also be abnormal.

It occurs when bronchial tubes get irritated. A cough expels mucous from the lungs at a faster rate than cilia do. Another protection mechanism is through bronchospasm.

The airways inside the lungs are normally surrounded by a bunch of muscle which can tighten when the lungs get irritated.

This muscle tightening can cause the breathing tubes to narrow as the lungs struggle to take out the irritant. This rapid tightening of the muscle is referred to as bronchospasm.

However, bronchospasm can lead to serious problems, especially for people with conditions like asthma, since it can make it harder to breathe via narrowed airways.