Hebrews 5:12 (Go to this verse :: Verse pop-up). In context, God tells us one of the purposes of His revelation to mankind. The writer of Hebrews scolds his audience for being dull of hearing (verse 11).
Prostaglandins are found in most tissues and organs. They are produced by almost all nucleated cells. They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. They are synthesized in the cell from the essential fatty acids (EFAs).
Mast cells are granulated cells typically found in connective tissue. These cells mediate immune responses to foreign particles. In particular, they release large amounts of histamine and enzymes in response to antigen recognition.