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.
Contusions are the most common type of bruises and are typically caused by blunt-force trauma. If the trauma damages the blood vessels under the skin, a bruise known as a contusion may appear. A contusion is typically identified by the color shifting of the skin as the injury transitions through the healing process.