|
|
Calcitonin is a naturally occurring hormone. In women who are at least 5 years beyond menopause, it slows bone loss and increases spinal bone density.
The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.