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. bsapp.com

• 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

single hair bsapp.com

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] bsapp.com

Medullary Index?

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