Atelectasis is composed of 78% nitrogen and 21% oxygen. Since oxygen is exchanged at the alveoli-capillary membrane, nitrogen is a major component for the alveoli's state of inflation. If a large volume of nitrogen in the lungs is replaced with oxygen, the oxygen may subsequently be absorbed into the blood, reducing the volume of the alveoli, resulting in a form of alveolar collapse known as absorption atelectasis. It is usually associated with accumulation of blood, fluid, or air within the pleural cavity, which mechanically collapses the lung. This is a frequent occurrence with pleural effusion, caused by congestive heart failure (CHF).
Cold and heat adaptations in humans air temperature from reaching the skin. There has been very little research done in the genetics behind adaptations to heat and cold stress. Data suggests that certain parts of the human genome have only been selected for recently. Research on gene-culture interaction has been successful in linking agriculture and lactose tolerance. However, most evidence of links between culture and selection has not been proven. Cold and heat adaptations in humans Cold and heat adaptations in humans are a part of the broad adaptability of "Homo sapiens". Adaptations in humans can be physiological, genetic, or cultural, which allow people to live