Q: What exactly are urban legends? A: Urban legends are popular stories alleged to be true and passed from individual to individual via oral or written (e.g. forwarded email) communication.: What exactly are urban legends? A: Urban legends are popular stories alleged to be true and passed from individual to individual via oral or written (e.g. forwarded email) communication.
When a person gets injured, their brains release chemicals called opioids into the space between neurons that acts to dull the pain signals. The effect is seen the most in the brain regions called the ventral striatum, amygdala, midline thalamus, and periaqueductal gray.
The Asthma Center. Leukotriene Modifiers. Leukotrienes are very powerful chemicals released by mast cells in the airways, and they are an important cause of asthma. Leukotriene modifiers have been available since 1997 for the treatment of asthma.