Characteristics of Hair
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Anatomy of a Hair
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Follicle
• Hair is an appendage of the
skin that grows out of a hair
follicle.
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The follicle contains more than
enough cells for simple DNA
Analysis
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Root
• The length of a hair extends
from the root embedded in the
follicle.
• A single root
contains
sufficient DNA
for analysis
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Cuticle
• The cuticle is the outside
covering of the hair.
• It is formed by overlapping
scales that always point toward
the tip of the hair.
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• These scales are formed from
special cells that are hardened
and flattened while progressing
from the follicle.
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Cortex
• the interior of the hair
• embedded with pigment granules
that impart color to hair
• composed of spindle-shaped
cortical cells aligned in a regular
array, parallel to the length of the
hair
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Pigment granules are absent in grey hairs
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Medulla
• a collection of cells which appears
as a canal running though the center
of the hair
• the medulla is the most
predominant hair feature in many
species
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Medulla:
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Types of Medulla
Continuous-Interrupted-Fragmented
.
Serial medulla is the term used to a
describe multiple medulla within a
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single hair
Type of Medulla?
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Medullary Index
The percentage or fraction of the
hair’s width occupied by the
medulla
[between 0 and 1]
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Medullary Index?
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