Thyroid-Stimulating Hormone (TSH). Guide. A thyroid-stimulating hormone (TSH) blood test is used to check for thyroid gland problems. TSH is produced when the hypothalamus releases a substance called thyrotropin-releasing hormone (TRH). TRH then triggers the pituitary gland to release TSH.
A Raven is black but depending on which way the light hits it they change to other colors like bluish, dark red, or greenish. There are white Ravens but are not albino.
I believe ravens symbolize darkness, just as in Poe's poem, The Raven.. These are birds that observe, as if lurking and waiting for their next victim. They can be wily and scary. ---------- The raven symbolizes many different things to different peoples. In most traditions you see a link to death.