Those blue bulging veins, which protrude from the skin, usually on the legs and thighs are called varicose veins. Spider veins are smaller, but also appear on the skin's surface. Approximately 25 million Americans suffer from peptic ulcer disease at some point in their lifetime. Each year there are 500,000 to 850,000 new cases of peptic ulcer disease and more than one million ulcer-related hospitalizations . B cells are lymphocytes or cells of the lymphatic system.
B cells develop in the bone marrow, hence their name.
B cells produce antibodies . In the last several years, the computer has become almost a necessity in our lives. The term smog is generally used to mean chemical air pollution. Smog primarily comes from the combustion of fossil fuels. A common example is car exhaust, which comes from the combustion of gasoline .