How Do Your Lungs Work?

How Do Your Lungs Work?

Do you know that you take approximately 6 million breaths every year? The lungs are the chief organs responsible for breathing.

But have you ever wondered how these lungs work or how can you take care of them? The following article will explain the basic structure of the lungs and tips to keep them healthy.

Structure of Lungs

The lungs are present in your chest just behind the rib cage. There is one lung on either side of your heart. Lungs have a conical shape with a rounded point on their apex. Their base is flatter and that is where they meet the diaphragm.

The lungs exist and work as a pair. However, both of your lungs are not of equal size and shape.

The left lung possesses and indentation bordering, specifically where your heart resides. This indentation is what you know as the cardiac notch. The right lung is relatively shorter to provide enough space for the liver just below it.

Overall, the weight and capacity of the left lung are slightly lower than the right one.

There are two membranes surrounding the lungs called the pulmonary pleurae. The inner layer is directly lining the outer surfaces of the lungs. The outer layer, on the other hand, is in contact with the inner wall of your rib cage.

The space between two membranes has fluid in it which you know as pleural fluid.

How Do Your Lungs Work?
Image by CDC
The Function of the Lungs

The main function of the lungs is to bring in the air from your surrounding inside the body. Once inside, these organs draw oxygen from it and pass it to your bloodstream. From there, the oxygenated blood keeps circulating to the entire body.

However, you require help from other structures outside the lungs to breathe. For example, you require the diaphragmatic muscle, intercostal muscles and the muscles of the abdomen. Sometimes, the muscles in the neck may participate as well.

The diaphragm is a muscle with a dome shape sitting just below the lungs. It provides power for most of the work you perform during breathing.

As it contracts, the diaphragm moves down increasing the space in the chest cavity. This provides more space for the lungs to expand and increase their capacity.

As the volume of your chest cavity increases, the pressure inside reduces. This makes you suck in air through mouth or nose and pass it all the way to the lungs.

As the diaphragm relaxes and assumes its resting position, the volume of lung depletes. This is because the pressure within the chest cavity increases and the lungs start expelling the air.

Your lungs are just like bellows. As they expand, they suck in the air to separate oxygen. As they compress, they exchange carbon dioxide waste out via exhalation.

When the air enters in through mouth or nose, it travels into the trachea or the windpipe. After crossing the trachea, it finally reaches an area called the carina.

At the carina, the windpipe breaks down into two to form to 2 mainstem bronchi. One of these stems leads to the left lung while the other goes to the right one.

From there, the pipe-like bronchi divide to form smaller bronchi just like branches of a tree. These further divide into even smaller bronchioles. This decreasing pipework eventually stops in the alveoli- the small air sac endings.

This is where the gaseous exchange occurs.

The Alveoli

The alveoli are the endpoints for oxygen coming from the external environment. The alveoli are actually small sacs, microscopic in size. Each of these sacs contains a fine mesh of various capillaries.

Every human being has almost 700 million individual alveoli. The total surface area of membranes of these alveoli is around 70 meters squared. This is approximately equal to the size of half a tennis court.

After the lungs, your body takes out oxygen from the bloodstream. Various tissues of your body use it as the blood circulates through the vascular system.

The blood that provides oxygen to the tissues receives carbon dioxide in return. Your heart receives this blood back where it travels to the lungs again. In the lungs, it reaches the alveoli to oxygenate itself once again.

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The alveoli now contain a fresh supply of oxygen coming from the air you just breathed. The oxygen from this air crosses a membrane, the alveolar-capillary membrane. Once it crosses it, the oxygen enters the bloodstream to re-oxygenate it once again.

At the same time, your lungs also have mechanisms to get rid of the carbon dioxide in the blood. This carbon dioxide separates from the blood, crosses the membrane to reach lungs. From there, your body breathes it out back to the atmosphere during the process of exhalation.

In simpler words, your lungs take in oxygen and release carbon dioxide. This is what you know as the gaseous exchange.

The Surfactant in the Lungs

There are some specialized cells in your alveoli responsible for producing surfactant. Pulmonary surfactant is a compound which consists of proteins, carbohydrates, and lipids.

Surfactant consists of a hydrophobic and a hydrophilic region. The hydrophilic regions possess an affinity for water. On the other hand, the hydrophobic areas are repelled by the presence of water.

Pulmonary surfactant is extremely important for the intact functioning of the lungs. Some vital functions of this surfactant include:

  • Allowing a better breathing capacity
  • Preventing the collapse of the alveoli

Each alveolus is comparable to a plastic bag which is wet inside. In the absence of a surfactant, the bag would eventually collapse on itself as the insides of it would stick together. The presence of surfactant ensures that the walls of alveoli remain intact and do not break down.

Pulmonary surfactant performs its role by decreasing the amount of surface tension. In this way, it reduces the efforts required to inflate alveoli.

The production of surfactant in an unborn baby does not start until the last weeks of gestation.

This is why the babies born preterm often struggle with breathing problems. Such breathing problems are collectively known as respiratory distress syndrome (RDS).

How Do Your Lungs Work?
Image by Wikipedia
How can you Protect Your Lungs?

Since lungs play a very important role in your breathing and hence, the survival, it is important to take care of them. Follow these simple steps to maintain a good health of your lungs.

Avoid Smoking

Smoking tobacco, both first and second hand, may lead to lung cancer. It may even cause COPD problems including emphysema or chronic bronchitis. Smoking narrows down the airways and causes inflammation of the lungs.

With long-term smoking, you are actually destroying the lung tissue over time. So make sure not to smoke and also to make your home a smoke-free area.

Prevent Infections

It is better to avoid infecting your lungs as much as possible. Try washing hands more often and avoid crowdy areas, especially during the flu season. Ask your doctor about the vaccinations for pneumonia and influenza.


Aerobic exercises improve the capacity of your lungs. It helps you stay fit and also prevents various breathing diseases which may affect the lungs.

Go for Frequent Checkups

Regular health check-ups, even when you are feeling good, can help pre-diagnose a lot of problems. This makes them more treatable without causing much damage.

Avoid Pollutant Exposure

Chemicals in your home and garden may damage your lungs and affect breathing. So wear a mask if you have to use these chemicals. Radon is a strong chemical and has associations with lung cancer deaths.

Nancy Walker

Nancy holds a Medicine degree and a Masters of Science MS in Infectious Disease and Global Health (MS-IDGH) from Tufts University. She worked as a lecturer for three years before she turned towards medical writing. Her area of interest are infectious diseases; causes, mechanism, diagnosis, treatments and prevention strategies. Most of her writings ensure an easy understanding of uncommon diseases.

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