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.
A knee contusion is a bruised knee, according to the American Society of Orthopaedic Surgeons. Contusion is medical jargon for a bruise. Contusions are one of the most common injuries. They are caused when either direct or repeated blows to an area damage muscle and connective tissue without breaking the skin.