How do the Lungs Work?
The lungs are sack-like, flexible organs in the chest that are connected to the outside world through the throat, and from there, through the nose and mouth. The left lung is slightly smaller than the right lung, to make room for the heart, which is located nearby. They, like the heart, are protected by the ribcage.
The lungs themselves do not control ‘breathing.’ Instead, muscles outside of the lungs manage breathing. Breathing happens as the muscles of the chest wall, abdominal muscles, neck muscles, and diaphragm move, changing the pressure in the chest cavity. Because the rest of the body is sealed, and the lungs are connected to the outside, only the lungs are able to expand and contract. This allows the body to pull in new air and expel out old air. These expansions and contractions happen with every breath. However, this also means that deep injuries to the chest or abdomen can make breathing difficult, as it breaks this seal.
Breathing is subconscious – the body does it automatically. However, these muscles can also be consciously controlled, which lets people breathe faster or slower at will, and even hold their breath.
Healthy lungs can hold, on average, 6 liters of air though this varies from person to person, though the lungs do not use all of it in each breath.
The lungs are not totally hollow. They are made up of flexible networks of bronchial tubes, which constantly branch off into clusters called alveoli. Blood vessels are woven around these alveoli, allowing oxygen to pass through the tissues of the alveoli into the blood, and carbon dioxide and other waste products to pass back into the lungs, where it is breathed out. The network of tubes gives the lungs a surface area that lets it use the air efficiently. However, the lungs are not fully filled with each breath, unless a person chooses to breathe particularly deeply.
The lungs are coated with a mucous layer to keep the tissues from drying out and protect it from dirt, allergens, and bacteria from the outside world. This mucous is constantly being produced and pushed out of the lungs to keep the lungs clean and healthy.
Sometimes, though, the lungs overproduce mucous and clog the airways. The lungs can also be affected by fluid retention, pulling fluids from the oversaturated blood stream and damaging the surrounding tissues. Because the oxygen that they provide is so vital, the lungs have an effect on every organ in the body, and, therefore, nearly every symptom of lupus.