[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Histology](https://durgical.com/en/histology/) › [The cell](https://durgical.com/en/histology/#a-cell) › Cytoskeleton: microfilaments, intermediate filaments, microtubules

[Histology](https://durgical.com/en/histology/) · [The cell](https://durgical.com/en/histology/#a-cell)

# Cytoskeleton: microfilaments, intermediate filaments, microtubules

- Topic

The cytoskeleton is the cell's inner scaffold: it gives shape, moves the cell and shares out the chromosomes when it divides.

Updated 2026-11-01

**See it in 3D:** [Skin](https://durgical.com/en/anatomy/skin/)

## Key points

- Thickness: actin
- Motor proteins walk along microtubules: kinesin carries cargo toward the plus end (anterograde, toward the axon terminal) and dynein toward the minus end (retrograde).
- Microtubules grow from the centrosome, which holds two centrioles of nine triplets.
- Myosin pulls on actin filaments for muscle contraction and to pinch the cell in two at cytokinesis.

## The three filaments

| Filament | Diameter | Protein | Function | Clinical |
| --- | --- | --- | --- | --- |
| Microfilament | About 7 nm (thinnest) | Actin | Core of microvilli, contraction with myosin, cytokinesis ring, cell migration | Wiskott-Aldrich syndrome (actin regulation) |
| Intermediate filament | About 10 nm | Keratins, vimentin, desmin, GFAP, neurofilaments, nuclear lamins | Resists tension; anchors desmosomes and hemidesmosomes | Epidermolysis bullosa simplex (keratins 5 and 14); tumour markers |
| Microtubule | About 25 nm (thickest), hollow tube | Alpha and beta tubulin | Mitotic spindle, vesicle transport, cilia and flagella | Colchicine, vinca alkaloids and taxanes; primary ciliary dyskinesia |

## Markers

- Cytokeratin: epithelia and carcinomas
- Vimentin: mesenchyme and sarcomas
- Desmin: muscle
- GFAP: astrocytes and gliomas
- Neurofilament: neurons

## Clinical notes

- Colchicine blocks microtubule polymerisation in neutrophils and dampens gouty inflammation.
- Vinca alkaloids (block assembly) and taxanes (block disassembly) halt mitosis in tumour cells; peripheral neuropathy is a typical side effect.
- Epidermolysis bullosa simplex: faulty keratins 5 and 14; basal cells break with friction and blisters form.

## Memory aid

Actin acts, intermediates endure, tubules transport: movement, strength and rails.

## Test yourself

Think of the answer, then tap the question to see it.

## Which intermediate filament identifies a tumour of epithelial origin on immunohistochemistry?

Cytokeratin; vimentin points to mesenchymal origin, desmin to muscle and GFAP to glia.

## Which motor protein carries cargo toward the neuron's cell body (retrograde transport)?

Dynein, which moves toward the minus end of microtubules.

## How do taxanes act on microtubules?

They stabilise microtubules and prevent disassembly, which arrests the cell in mitosis.

## Which proteins fail in epidermolysis bullosa simplex?

Keratins 5 and 14 of the basal keratinocytes, intermediate filaments that resist friction.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/histology/cytoskeleton-microfilaments-intermediate-filaments-microtubules/)

## See it in 3D

The structures of Durgical's 3D anatomy where it is found.

- [Skin](https://durgical.com/en/anatomy/skin/)

## Related

- [Cilia, microvilli and stereocilia](https://durgical.com/en/histology/cilia-microvilli-and-stereocilia/)
- [Cell junctions: tight, adherens, desmosomes, gap, hemidesmosomes](https://durgical.com/en/histology/cell-junctions-tight-adherens-desmosomes-gap-hemidesmosomes/)
- [Cell cycle, mitosis and meiosis](https://durgical.com/en/histology/cell-cycle-mitosis-and-meiosis/)
- [Skeletal muscle: sarcomere and contraction](https://durgical.com/en/histology/skeletal-muscle-sarcomere-and-contraction/)
- [The neuron and synapse](https://durgical.com/en/histology/the-neuron-and-synapse/)

## In Pharmacology

- [Colchicine](https://durgical.com/en/pharmacology/colchicine/)
- [Vincristine](https://durgical.com/en/pharmacology/vincristine/)
- [Paclitaxel](https://durgical.com/en/pharmacology/paclitaxel/)

[← All of histology](https://durgical.com/en/histology/)

Educational content on normal microscopic structure and its clinical relevance; no substitute for studying slides or for a health professional's advice.

Sources: [3.2 The Cytoplasm and Cellular Organelles](https://openstax.org/books/anatomy-and-physiology-2e/pages/3-2-the-cytoplasm-and-cellular-organelles) (OpenStax (Rice University), 2022); [3.5 Cell Growth and Division](https://openstax.org/books/anatomy-and-physiology-2e/pages/3-5-cell-growth-and-division) (OpenStax (Rice University), 2022); [Epidermolysis bullosa simplex](https://medlineplus.gov/genetics/condition/epidermolysis-bullosa-simplex/) (MedlinePlus Genetics (U.S. National Library of Medicine), 2024).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/histology/cytoskeleton-microfilaments-intermediate-filaments-microtubules/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/histology/cytoskeleton-microfilaments-intermediate-filaments-microtubules/