What is the function of our lungs?
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Taking a breath of fresh air is one of the most gratifying pleasures in life we take for granted. One that we become cutely aware of when our breathing becomes impaired. We take in approximately 23,000 breaths daily without even thinking about it. The air we breathe in contains several gases and most importantly oxygen. It is oxygen your cells need to function. The main function of your lungs is to add fresh oxygen to your blood which in turn is carried to your cells and to expel the carbon dioxide that is released by the cells to the environment. This process is known as respiration.
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Lung function normally peaks in the late teens and early twenties. After the early twenties, lung
function declines about 1 percent a year over the rest of a person's lifetime. Lung function decreases
about 2 percent a year for people who smoke.
Take a look inside your lungs
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Both your lungs are located in your chest, and are protected by the rib cage. The left lung is a little smaller than the right lung because it shares space in the left side of the chest with the heart.
The lungs are surrounded by two membranes, the pleurae. The outer pleura covers and is attached to the chest wall and is known as the parietal pleura. The inner one covers and is attached to the lung and other visceral tissues i.e. vessels, bronchi and nerves and is known as the visceral pleura. In between the two is a potential thin space known as the pleural cavity or pleural space.
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As you breathe in air moves through the windpipe (trachea), which branches into two smaller airways: the left and right main stem bronchi, which lead to both lungs. The intersection at the main bronchus is known as the crania. Each bronchus branch out & becomes smaller in size. This is known as bronchioles (30,000 in each lung), and at the end of each bronchiole is a special area that leads into clumps of teeny tiny air sacs called alveoli. The air travels through the bronchioles and finally ends up in the alveoli (we have 600 million). Oxygen passes through the walls of each alveolus into the tiny capillaries that surround it. The oxygen enters the blood in the capillaries, on red blood cells that then travels through layers of blood vessels to the heart. The heart then sends the oxygenated (filled with oxygen) blood out to all the cells in the body.
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When you breathe out the exact opposite happens. After the cells have used the oxygen they need,
blood carrying carbon dioxide and other wastes blood comes back through the capillaries and the
wastes enter the alveoli. You then breathe them out in the reverse order of how they came in: the
air goes through the bronchioles, out the bronchi, out the trachea, and finally out through your
mouth and nose.