The Anatomical Zodiac Man is a 15th-century medical-astrological diagram mapping the twelve zodiac signs to human body parts, from Aries (head) to Pisces (feet). Used by medieval physicians and surgeons, it determined the safe timing for bloodletting or surgery based on the Moon's position, as treating a body part ruled by a specific sign was deemed dangerous.

Key Aspects of the Zodiac Man:

• Purpose: It was a crucial diagnostic tool for medical practitioners to avoid performing procedures when the moon was in the sign governing a particular body part.

• Anatomical Correspondences: Aries: Head/face Taurus: Neck/throat Gemini: Shoulders/arms/lungs Cancer: Chest/breasts Leo: Heart/back Virgo: Abdomen/intestines Libra: Kidneys/hips Scorpio: Reproductive organs/rectum Sagittarius: Thighs Capricorn: Knees Aquarius: Ankles/legs Pisces: Feet

• Origin & Usage: While appearing in various manuscripts, a famous early version is found in the Fasciculus Medicinae (1491). It represents the medieval belief that man is a microcosm, reflecting the macrocosm of the universe.

• Key Examples: The illustration in Les Très Riches Heures du Duc de Berry (c. 1411–1416) by the Limbourg Brothers is a famous example.

• Decline: The use of the Zodiac Man began to wane with the rise of empirical anatomy, notably criticized by Andreas Vesalius in the 16th century, who prioritized direct observation over astrological influence. 

It was widely used to align medical treatment with celestial influences, ensuring that a "member of the body" was not cut with iron when the moon was in its corresponding sign.