Cuticle (hair)

The hair cuticle is the outermost part of the hair shaft.^[1] It is formed from dead cells, overlapping in layers, which form scales that strengthen and protect the hair shaft.^[2][3] These layers are formed of keratin proteins.^[4] The hair cuticle is also known to contain anteiso-18-methyleicosanoic acid which contribute to the hydrophobic properties of hair. ^[5][4]

Diagram of the hair shaft, indicating medulla (innermost), cortex, and cuticle (exterior)

Comparison of sheep (top) and human (bottom) hairs with different cuticle textures

While the cuticle is the outermost layer, it is not responsible for the color of the hair. Melanin is the pigment that gives hair its color and is found in the cortex.^[6]

See also

• List of distinct cell types in the adult human body

References

1. James, William; Berger, Timothy; Elston, Dirk (2005) Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. Page 8. ISBN 0-7216-2921-0.
2. "Hair!". Worsleyschool.net. Retrieved 2016-06-13.
3. "Hair". British Medical Association Complete Family Health Encyclopedia. Dorling Kindersley Limited. 1990.
4. "Known and Unknown Features of Hair Cuticle Structure: A Brief Review". Cosmetics.
5. "The role of 18-methyleicosanoic acid in the structure and formation of mammalian hair fibres". Micron.
6. "Hair biology - hair fiber". Keratin.com. Archived from the original on 2020-08-01. Retrieved 2013-08-18.