|
|
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
There are major differences in the metabolism of morphine and the illegal drug heroin. Morphine mostly produces its CNS effects through m-receptors, and at k- and d-receptors. Heroin has a slight affinity for opiate receptors. Most of its actions are due to metabolism to active metabolites (6-acetylmorphine, morphine, and morphine-6-glucuronide).
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
Cyanide works by making the human body unable to use oxygen.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.