Meical astrology (traditionally known as Iatromathematics) is an ancient medical system that associates various parts of the body, diseases and drugs as under the influence of the Sun, Moon and planets, along with the twelve astrological signs. Each of the astrological signs (along with the Sun, Moon, and planets) are associated with different parts of the human body. Also, many plants are referred to in old treatises on herbs as being "under the influence of" some planet. This was used as a codification of associations of the signs with the parts of the body are as follows: