It is estimated that there are around 150 million alveoli in each lung that provide a large surface area for gaseous exchange to occur. The walls of the alveoli are extremely thin and are made up of a single layer of squamous epithelial cells; these cells produce alveolar fluid which keeps the walls moist so that the gases are dissolved before diffusing. Surrounding the alveoli sacs, are a network of pulmonary capillaries that together form an extremely thin membrane, this...
It is estimated that there are around 150 million alveoli in each lung that provide a large surface area for gaseous exchange to occur. The walls of the alveoli are extremely thin and are made up of a single layer of squamous epithelial cells; these cells produce alveolar fluid which keeps the walls moist so that the gases are dissolved before diffusing. Surrounding the alveoli sacs, are a network of pulmonary capillaries that together form an extremely thin membrane, this allows oxygen present in the alveoli to be diffused into the blood capillaries and for carbon dioxide to be diffused from the blood capillaries back into the alveoli before being excreted into the atmospheric air.
Macrophages patrol the alveoli and look for pathogens that make it past the conduction passageways and eliminates them.
Millions of pathogens float in the air. Each breath brings those particles into the respiratory tract, increasing the risk of a respiratory infection. Pneumonia is a pathogenic infection of the lungs, caused by a variety of different pathogens that colonise the alveoli, they eventually multiply and begin to invade lung tissue. As the alveoli become infected it begins to fill up with mucus and pus, white blood cells then begin to attack the pathogens, and the infected area becomes inflamed. This disrupts the normal process of the gas exchange, as it stops oxygen from reaching the bloodstream and carbon dioxide from being excreted which can cause someone difficulty in breathing.
