HOME
Front page
Credits
Links
MyBodyIndex:
Human Body Guide
Nutrient Guide
Disorder Guide
Remedies & Therapies
The Human Body:
|
Lungs
IMAGE COMING SOON
Diagram 7.2 lungs
Lungs are situated in the thoracic cavity, separated from the abdominal cavity by the diaphragm. The lungs are like sponges, filled with tiny holes. Once one breathes in, the lungs expand as the holes fill with air. They are very flexible and light. The maximum amount of air that they can hold is abut 3 litres of air. Healthy lungs are pink but gradually with pollution and age, they will turn grey or black. Each lung is surrounded by a thin transparent lining, the pleura. This folds back on itself to form a double layer around the lung. The inner layer(lung pleura) is tightly attached to the lung while the outer layer(rib pleura) is partly attached to the rib cage. Between the 2 layers, there is a tiny amount of fluid, that acts as a lubricant for the gliding movements during breathing. The 2 lungs are of unequal sizes. The left one is smaller and weighs about 100g less. The right lung has 3 lobes. The left only 2 so that there is enough space for the heart. The lungs contains about 300-450 million alveoli. The alveoli have a surface area of about 70 m2.
|