If a lightning strike is a sufficient distance from the observer, sound from the strike will not be heard. These silent bolts are called heat lightning. Lightning bolts produce thunder, but the thunder sound does not travel all the way to the observer if the observer is too far away. The movement of sound in the atmosphere depends on the atmospheric properties of the air such as temperature and density.
Collagen vascular diseases are autoimmune diseases that affect connective tissues, and occur when the bodyâs immune system attacks its own tissues and organs. Lupus is often characterized by a facial rash on both cheeks. Lupus patients may experience fatigue, joint pain, skin lesions and shortness of breath.
The Causes And Effects Of Collagen Loss By NewBeauty Staff | July 12, 2010 Collagen is a tough, almost rubbery protein that's created by cells called fibroblasts. Packed together as bundles, fibrous bands of collagen serve as the main support system of the dermis, the deepest layer of skin. Collagen gives skin its strength, and it makes skin firm and flexible with the help of elastin. Collagen is essential for young-looking skin because it gives structure to its cells. When collagen levels becomes depleted, the skin has little internal support, causing it to sag and contributing to wrinkles. Furthermore, when there is ample collagen in the skin, it's strong and more resistant to the effects of weight gain, so a lack of it can lead to a greater risk of stretch marks. Around age 35, collagen production naturally begins to taper off, and the quality of the collagen diminishes.