The Sun rules the mind and willpower, energy, vitality, wholeness and self-integration, dominion, organization, and power in general.
Physiologically, the Sun rules the heart, circulation, the vertebral column, health and vitality in general, and the heart meridian of acupuncture; in addition, the distribution of heat in the body, the thymus gland, the pons Varolii (function: control of the breath), and the eyes (especially the right eye of man and the left of woman). Together with Saturn and the signs of Virgo and Scorpio, the Sun rules the spleen.
The energies transformed by the spleen are carried to the solar plexus, from where they spread over the whole body. (Compare the significance and function of the spleen for energy economy in Chinese medicine.)
The image of the Sun is masculine, conscious, and libido-like.
The diseases associated with the Sun are organic, constitutional, and structural.