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Author Question: As adults, well-off Black Americans are less likely to have acquired knowledge from their parents ... (Read 12 times) |
If all the neurons in the human body were lined up, they would stretch more than 600 miles.
There are 20 feet of blood vessels in each square inch of human skin.
In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.