Earth's Atmospheric Layers. Diagram of the layers within Earth's atmosphere. Troposphere. The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.Stratosphere. The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high.he troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.
A bruise, or contusion, is a type of hematoma of tissue in which capillaries and sometimes venules are damaged by trauma, allowing blood to seep, hemorrhage, or extravasate into the surrounding interstitial tissues.
View full size image. A contusion, or bruise, is a reddish-purple discoloration of the skin that doesn't blanch, or turn white or pale, when pressed upon. Bruises typically form when a localized injury, such a blow or impact, causes capillaries to break open and leak red blood cells under the skin.