Which of the following meridians is NOT classified as a yang meridian?

The heart meridian is classified as a yin meridian. In traditional Chinese medicine, meridians are categorized into two groups: yin and yang, based on their characteristics and associations. Yin meridians are typically linked to solid organs and have qualities that are nurturing, restorative, and often associated with body fluids and blood. The heart, being a vital organ responsible for the circulation of blood and housing the mind, is considered yin due to its vital, nourishing properties and role in maintaining overall health.

In contrast, yang meridians are related to hollow organs and involve activities associated with energy, movement, and external functions. The small intestine, gallbladder, and large intestine meridians are all classified as yang because they are linked to processes that involve digestion, storage, and elimination, emphasizing action and transformation. This distinction is essential in acupuncture as it informs treatment approaches based on the nature of the imbalance present in a patient's condition.