Which of the following is the storage form of iron found in the liver and spleen?

The storage form of iron found in the liver and spleen is ferritin. Ferritin is a protein complex that plays a crucial role in iron metabolism. It functions by sequestering and storing iron in a non-toxic form, allowing it to be released in a controlled manner when needed for various physiological processes, especially for hemoglobin synthesis and other functions requiring iron.

When the body has excess iron, ferritin levels can increase, as it helps to prevent free iron from causing oxidative damage. In pathological conditions, such as hemochromatosis, iron overload can lead to the accumulation of hemosiderin, which is a less readily available form of stored iron. However, in normal physiology, ferritin is the principal form of iron storage in the liver and spleen.

Transferrin is a transport protein that binds iron in the bloodstream and delivers it to various tissues, rather than a storage form. Myoglobin is a protein that carries oxygen in muscle cells, not related to iron storage in the liver or spleen. Thus, ferritin is the correct choice as the primary storage form of iron within these organs.