What is "hita"

Hitā ( Sanskrit: हिता) means 'causeway' or 'dike'. In the Upanishads this word is used to mean 'subtle connections' or 'canals of subtle energies', or particular 'nerves' or 'veins'. The journey to the heart is said to be through seventy-two thousand subtle channels called Hitā; they are the beneficent active veins (filled with different types of serums).