Structure of the Lungs

The lungs are located in the chest inside a lubricated membrane called the pleural membrane.This allows the lungs to move freely inside the pleural cavity. The lungs are connected to the outside via the trachea (windpipe). The trachea is a tube kept in a rigid shape due to rings of cartilage. The larynx or voice box is located at the top of the trachea while at the bottom end it branches into two bronchi. These lead into the lungs.

The bronchi in turn branch off into smaller and smaller bronchioles. These end in tiny air sacs called alveoli. It is here that gaseous exchange takes place. The surface area of all these alveoli is very large so as to be able to absorb oxygen very quickly.

The lungs are very delicate and can easily be damaged. The cells lining the airways have very tiny hair like structures called cilia on them. These cilia are coated in a sticky mucus. The beating cilia force the mucus and any particles of dirt up out of the lungs. It eventually drops down into the oesophagus so the mucus is attacked by the stomach acid, destroying any pathogens.

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2005 Psionica