The familiar sounds of your heart are made by the heart's valves as they open and close.
Did you know?
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
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The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.
Did you know?
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).
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Although not all of the following muscle groups are commonly used, intramuscular injections may be given into the abdominals, biceps, calves, deltoids, gluteals, laterals, pectorals, quadriceps, trapezoids, and triceps.
Wilting in plants.
Body plan axes in animals and plants
Structure of chlorophyll molecules in chloroplasts of plants
