Woodcut titled "The Anatomy of Man's Body as govern'd by the Twelve Constellations" from Benjamin Franklin, "Poor Richard's Almanack", Philadelphia, 1750. The figure of a man with the signs of the zodiac connected to their corresponding body parts. Medical astrology (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. Zodiac to body part is as follows: Aries: head, face, brain, eyes, Taurus: throat, neck, thyroid gland, vocal tract, Gemini: arms, lungs, shoulders, hands, nervous system, brain, Cancer: chest, breasts, stomach, alimentary canal, Leo: heart, chest, spine, spinal column, upper back, Virgo: digestive system, intestines, spleen, nervous system, Libra: kidneys, skin, lumbar region, buttocks, Scorpio: reproductive system, sexual organs, bowels, excretory system, Sagittarius: hips, thighs, liver, sciatic nerve, Capricorn: knees, joints, skeletal system, Aquarius: ankles, calves, circulatory system, Pisces: feet, toes, lymphatic system, adipose tissue.