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Author Question: The myelin sheath surrounding axons in brain is formed by ________. Fill in the blank with the ... (Read 52 times) |
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.
Parkinson's disease is both chronic and progressive. This means that it persists over a long period of time and that its symptoms grow worse over time.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
The familiar sounds of your heart are made by the heart's valves as they open and close.