What two organs account for the highest resting metabolic rate (RMR)?

The correct answer identifies skeletal muscle and the liver as the two organs that account for the highest resting metabolic rate (RMR).

Skeletal muscle is a metabolically active tissue, and it contributes significantly to overall energy expenditure, even at rest. It is involved in various physiological processes, including maintaining posture, movement, and thermogenesis, which account for a substantial portion of the body's resting energy needs. The liver also plays a critical role in metabolic processes, including gluconeogenesis, protein synthesis, and the regulation of various biochemical pathways. Given its central role in metabolism, the liver is a significant contributor to RMR.

In contrast, the heart and kidneys, while vital organs, do not have as high a metabolic rate as skeletal muscle and the liver. The brain, although it requires a significant amount of energy relative to its size, does not compare to the energy demands of skeletal muscle and liver when considering overall metabolic contributions. Adipose tissue, while important for energy storage and metabolism, has a lower metabolic activity compared to the other tissues mentioned, and the intestines, though active in digestion and absorption, do not contribute as significantly to RMR as skeletal muscle and liver. Thus, skeletal muscle and liver are the primary contributors to the resting metabolic