|
|
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.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
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.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.