Atelectasis be bibasal in pattern. Chest CT or Bronchoscopy may be necessary if the cause of atelectasis is not clinically apparent. Direct signs of atelectasis include displacement of interlobar fissures and mobile structures within the thorax, overinflation of the unaffected ipsilateral lobe or contralateral lung, and opacification of the collapsed lobe. Atelectasis may be an acute or chronic condition. In acute atelectasis, the lung has recently collapsed and is primarily notable only for airlessness. In chronic atelectasis, the affected area is often characterized by a complex mixture of airlessness, infection, widening of the bronchi (bronchiectasis), destruction, and scarring (fibrosis). The atmosphere
Cold and heat adaptations in humans to having more cells, and have a smaller surface area compared to smaller individuals, which reduces heat loss. A study by Frederick Foster and Mark Collard found that Bergmann’s rule can be applied to humans when the latitude and temperature between groups differ widely. Allen’s rule is a biological rule that says the limbs of an endotherm is either shorter in cold climates or longer in hot climates. Limb length affects the body’s surface area, which helps with thermoregulation. Shorter limbs help to conserve heat, while longer limbs help to dissipate heat. Marshall T. Newman argues that this can be