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.
During an allergic reaction, mast cells release histamine and other substances. Mast cell stabilizers, such as cromolyn sodium, keep these cells intact. Leukotriene inhibitors: Other substances released during an allergic reaction are leukotrienes, which can aggravate allergic conditions and asthma.