|
|
The familiar sounds of your heart are made by the heart's valves as they open and close.
The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.