What is considered the largest internal organ in the vertebrate body?

The liver is the largest internal organ in the vertebrate body, playing a crucial role in numerous bodily functions. It is involved in metabolizing nutrients from food, producing bile to aid in digestion, and detoxifying potentially harmful substances. With a weight of about 1.5 kilograms (3.3 pounds) in an average adult, the liver not only performs these essential tasks but also serves as a storage site for vitamins and minerals, including iron and vitamin A, which are vital for maintaining various physiological functions.

In contrast, the pancreas, while an important organ for digestion and blood sugar regulation, is smaller than the liver and does not perform the same range of functions. The stomach is primarily responsible for digestion and has a limited role compared to the extensive functions of the liver. The gallbladder, which stores bile produced by the liver, is also much smaller and has a more specific function in the digestive process. Therefore, the liver is recognized as the largest internal organ due to its size and the breadth of its critical functions within the vertebrate body.