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Published on: March 17, 2017
Hair medulla morphology and mechanical properties
1Departamento de Físico Química, Instituto de Química, Universidade Estadual de Campinas, UNICAMP CP 6154, 13083-970 Campinas, SP, Brazil.
Journal of Cosmetic Science
|August 31, 2007
Summary
The hair medulla
Area of Science:
- Human hair morphology
- Biomaterials science
- Textile science
Background:
- The hair medulla's structure and function remain poorly understood.
- Previous studies suggested the medulla has minimal impact on hair properties.
Purpose of the Study:
- To investigate the fibrillar structures within the hair medulla using transmission electron microscopy (TEM).
- To assess the influence of the hair medulla on the mechanical properties of human hair.
Main Methods:
- Transmission electron microscopy (TEM) was employed to analyze the fibrillar structures and cellular organization within the hair medulla.
- Mechanical properties of medullated and unmedullated hair fibers were compared.
Main Results:
- TEM revealed a CMC layer at the cortex-medulla interface and less dense material between medullary cells.
- Medullary cells exhibit crystalline microfibril arrangements, becoming scarce and disorganized centrally, with air-filled granules observed.
- Average mechanical properties were similar for medullated and unmedullated hair, but medullated hair showed greater data dispersion.
Conclusions:
- Air cavities within the hair medulla do not significantly alter average mechanical properties.
- The presence of a medulla leads to less uniform hair strength compared to unmedullated hair.
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