<span>Cocaine Preparations
-Coca leaves --> Coca Paste (60% pure): Not water soluble, so you can't inject it into the bloodstream -- you need an additional chemical step to turn the paste into crystal powder that can be injected or snorted
-Coca --> Cocaine Hydrochloride (99% pure): Doesn't hold up very well to heat, so you can't smoke cocaine hydrochloride
-Cocaine Hydrochloride (99% pure) --> Free-Base Cocaine or Crack Cocaine:
-Reconvert cocaine hydrochloride back to base state by removing hydrochloride from cocaine (that's why it's called free-base cocaine)
-Crack cocaine is a crystallized form, mixture of cocaine and baking soda
-75% pure
-Can be used at lower doses and is much cheaper than cocaine
-Can be smoked</span>
Receptors in muscles provide the brain with information about body position and movement. The brain controls the contraction of skeletal muscle. The nervous system regulates the speed at which food moves through the digestive track.