A fascinating voyage of discovery through the human body. Learn about what makes the body work and just how intricate human beings are--both inside and out. Sixty detailed drawings, designed for coloring, are enhanced by detailed text describing each illustration.a fact-filled coloring book Freddy Stark. Chemical Messengers Your ... are the adrenal (uh-DREE-nul) glands. The adrenal glands are part of the endocrine gland system and they secrete several hormones, including some steroid hormones.