Which organs are classified as solid organs?

The classification of organs into solid and hollow categories is essential for understanding their functions and roles in traditional Chinese medicine as well as in anatomy. Solid organs are defined as those that have a more defined structure and are typically involved in more stable, ongoing bodily functions, such as producing and storing substances.

In this context, the correct response identifies the lung, spleen, and heart as solid organs. The lungs, while often thought of in terms of air conduction, are vital for exchanging gases and play a significant role in metabolic processes. The spleen is integral for blood production, nutrient absorption, and immune function, highlighting its solid nature due to its structural density and key functions. Similarly, the heart is a core organ that pumps blood throughout the body, maintaining circulation and regulating bodily functions—again illustrating characteristics of a solid organ.

In contrast, the other options include organs that do not fit the solid classification. For instance, the large intestine and stomach, as mentioned in another choice, are hollow organs designed primarily for the digestion and transportation of food, not for storage or production. Likewise, the small intestine and bladder are also hollow organs; the small intestine's primary role is nutrient absorption while the bladder serves as a reservoir for urine. Lastly, organs such