Intermediate Filaments

The intermediate filaments are so named because they have an intermediate diameter - about 10 nm - relative to the other two types of protein filaments.

In cells lining the outermost layer of the skin, there is a large amount of an intermediate filament type called keratin. One of the roles of this filament is to prevent cells of this tissue from separating or rupturing by being, for example, stretched.

In addition to being scattered inside the cells, arming them, keratin molecules promote a "binding" between them at certain points, which ensures the stability of the tissue in case of action of any external agent that tries to separate them. This paper is similar to the iron bars that are used in the construction of a concrete column. Other cells have appreciable amount of other intermediate filaments. This is the case of connective tissue components and neurofilaments found within nerve cells.