THE HEART AND ITS ANATOMICAL CONSTITUTION

Unpublished Leaves original: "Feuillets inédits"; refers to the first public printing of these private notebooks, Library of Windsor Castle The location where the Royal Collection of Leonardo's drawings has been kept since the 17th century, heart, anatomical constitution, Édouard Rouveyre A prominent 19th-century Parisian publisher known for high-quality reproductions of historical manuscripts

## Anatomical study of the heart and the pulmonary vessels

This page contains a detailed anatomical study of the heart and the branching network of the pulmonary vessels (the bronchial tree). Leonardo investigates the physiological relationship between respiration and circulation. The text is written in his characteristic mirror script.

On the movements of air through the vessels of the lung.

The lung is the instrument of the voice, and its function is to renew and refresh the air in the heart, and to expel the tainted air and receive new air, which refreshes the blood that passes through its vessels—which blood has been heated by the continuous motion of the heart.

The air that exits the lungs is accompanied by the voice, and this voice is produced by the percussion made by the air in the vessels of the lung; this air is pushed by the diaphragm, which constricts the lung and the spirit original: "lo sspirito"; here referring to the vital breath or pneuma, a classical concept of life-force and that which constricts the lung by way of a breathing hole? that opens and closes according to the will of the animal.

A

Drawing of the heart at center, with a dense, tree-like network of vessels extending to the left, representing the vascularization of the lungs.

These vessels are those that carry the vital spirit to the members of the lung, and through these vessels of the spirits the air is infused into the blood, which blood is that which nourishes the lung itself and refreshes the heart.

Small diagrams to the right of the heart: a pair of...