|
|
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.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
Certain chemicals, after ingestion, can be converted by the body into cyanide. Most of these chemicals have been removed from the market, but some old nail polish remover, solvents, and plastics manufacturing solutions can contain these substances.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.