Which has highest mitotic index muscle skin kidney or lung?

Skin

The mitotic index is a measure of the rate of cell division in a tissue. It is calculated by dividing the number of cells in mitosis by the total number of cells in a sample. The mitotic index is highest in tissues that are rapidly growing or regenerating.

Muscle, skin, kidney, and lung are all tissues that undergo mitosis. However, the mitotic index is highest in skin. This is because the skin is constantly exposed to damage from the environment, and so it needs to be able to repair itself quickly. The mitotic index in muscle, kidney, and lung is lower because these tissues are not as exposed to damage.