The lungs
This page tells you about the lungs and how they work. There is information about
The lungs
The lungs bring oxygen into our bodies and pass it into the bloodstream so that it can circulate to every body cell. They are part of the body system we use to breathe. This is called the respiratory system.
The parts of the respiratory system
The windpipe divides into two airways, called the right main bronchus and the left main bronchus. One goes to each lung. Within the lungs, they divide into smaller tubes called the secondary bronchi. There are two of these on the left side and three on the right. Each secondary bronchus divides into smaller tubes called bronchioles.
The right lung is divided into 3 sections called the upper, middle and lower lobes. The left lung is divided into 2 sections called the upper and lower lobes.
The pleura
The pleura are 2 fibrous sheets of tissue that cover the lungs. Doctors usually call these the lining of the lungs, although this can be confusing as they are on the outside. The pleura are also called the pleural membranes. The gap between the pleura is called the pleural space. The pleura produce a lubricating fluid that fills the gap. This helps the lungs to move smoothly in the chest when they are inflating and deflating as we breathe.
Lung cancer can spread to the pleura. The cancer irritates the pleura and they then make too much fluid. The fluid collects and takes up space that the lung should occupy when you are breathing in. This is called a pleural effusion.
The lungs are part of the body system we use to breathe. This is called the respiratory system. It is made up of the
- Nose and mouth
- Windpipe (trachea)
- Airways to each lung (the right main bronchus and left main bronchus)
- The lungs
The windpipe divides into two airways. These are called the right main bronchus and left main bronchus. One goes to each lung.
Within the lungs, the left and right bronchus divide into smaller tubes called the secondary bronchi. There are two of these on the left side and three on the right. The lungs are slightly different on each side.
The right lung is divided into 3 sections called the upper, middle and lower lobes. The left lung is divided into 2 sections called the upper and lower lobes. You may hear your doctor talk about the lobes of the lung.
Each secondary bronchus divides into smaller tubes called bronchioles.
The pleura are 2 fibrous sheets of tissue that cover the lungs and help to protect them. Doctors usually call these the lining of the lungs, although for non medical people this can be a bit confusing as they are on the outside. The pleura are also sometimes called the pleural membranes.
The gap between the pleura is called the pleural space. The pleura produce a lubricating fluid that fills the gap between them. This helps the lungs to move smoothly in the chest when they are inflating and deflating as we breathe.
Lung cancer can spread to the pleura. The cancer irritates the pleura and they then make too much fluid.
The fluid collects and takes up space that the lung should occupy when you are breathing in. So your lung can't expand as much as it should and you feel breathless. If you have too much fluid between the pleura, this is called a pleural effusion.
The lungs bring oxygen into our bodies and pass it into the bloodstream so that it can circulate to every body cell. We use the muscles of our chest and a large flat muscle under the lungs (the diaphragm - pronounced di-a-fram) to draw air into the lungs. The diaphragm is at the base of the chest cavity, just above the stomach. The chest cavity is sealed so that when you breathe in and the muscles make it bigger, this causes a vacuum inside, which draws the air in through your nose and down into the lungs.
At the end of the smallest airways in the lungs (the secondary bronchii) are the smallest tubes, the bronchioles. These carry air throughout the lungs. At the end of the bronchioles are air sacs called alveoli. There are millions of these tiny sacs. This is where oxygen is absorbed into the bloodstream from the air that we breathe in. Once in the blood, the oxygen can travel throughout the body and reach every body cell.
As oxygen is being absorbed, carbon dioxide passes back into the alveoli from the bloodstream. This waste gas is removed from the body as we breathe out.
Lymph nodes (also called lymph glands) are small bean shaped glands. You find them throughout the body, connected by a network of tubes called lymphatics or lymphatic vessels. This network carries a clear fluid that leaks out of the blood vessels and bathes the body tissues and cells. The lymph nodes help to filter this fluid and the lymphatic vessels channel it back into the bloodstream.
Because lymph fluid circulates through body tissues, the lymphatic system is one of the ways that cancer can spread from one part of the body to another. This is why cancer surgeons and medical cancer specialists (oncologists) are always so keen to find out if there are any cancer cells in your lymph nodes when you are diagnosed. If there are cancer cells in the lymph nodes, this is a sign that the cancer may have spread and could affect your choice of treatment.
There is more information about the lymphatic system in the about your body section of CancerHelp UK.
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