Medicine & USMLE

Intermediate Filaments

  1. Microfilaments (Actin Filaments)
  2. Intermediate Filaments
  3. Microtubules


Intermediate Filaments are medium-sized fibers in your cytoskeleton which mainly provide structural support to the cell. They are commonly composed of keratin, although other types of intermediate filaments exist. Notably, intermediate filaments of adjacent cells can be linked together in desmosomes.

Key Points

  • Intermediate Filaments
    • Provides structural support, helps cell retain shape
      • Key component in desmosomes, which anchors the intermediate filaments of two cells together to increase tensile strength
    • Medium sized (diameter 10 nm)
    • Commonly composed of keratin, although may be made of different proteins
    • Static/permanent - cannot change size via polymerization or depolymerization