Which of the following statements best summarizes the traditional belief regarding the kidney and the brain?

The statement that the kidney fills the brain with essence accurately reflects traditional beliefs found in various Eastern medical philosophies, particularly within Traditional Chinese Medicine (TCM). In TCM, the kidneys are often seen as the source of vital essence (Jing), which is crucial for overall health and vitality, including cognitive functions. This essence is thought to play a vital role in nurturing the brain and supporting mental faculties such as memory, learning, and emotional regulation.

This understanding is rooted in the view that the kidneys are not merely organs associated with filtration and waste but are central to the storage and management of vital substances that influence various physiological and psychological processes. The connection underscores an integrated view of bodily systems, where the health of one organ can significantly influence the functioning of others, particularly in terms of sustaining mental processes.