Atelectasis Leakage of air into the pleural cavity (pneumothorax) also leads to compression atelectasis. It occurs when either local or generalized fibrotic changes in the lung or pleura hamper expansion and increase elastic recoil during expiration. Causes include granulomatous disease, necrotising pneumonia and radiation fibrosis. Chronic atelectasis may take one of two forms—middle lobe syndrome or rounded atelectasis. In right middle lobe syndrome, the middle lobe of the right lung contracts, usually because of pressure on the bronchus from enlarged lymph glands and occasionally a tumor. The blocked, contracted lung may develop pneumonia that fails to resolve completely and leads to
Cold and heat adaptations in humans with aborigines having a much lower sweat rate than whites. Social adaptations enabled early modern humans to occupy environments with temperatures that were drastically different from that of Africa. (Potts 1998). Culture enabled humans to expand their range to areas that would otherwise be uninhabitable. Humans have been able to occupy areas of extreme cold through clothing, buildings, and manipulation of fire. Furnaces have further enabled the occupation of cold environments. Australian aborigines only wear genital coverings for clothes, but studies have shown that the warmth from the fires they build is enough to keep the body from fighting heat