1. FORENSIC SCIENCE
Hair Anatomy
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2. Types of Hair
1. Guard hairs: outer coat of hair; provides
protection
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3. Types of Hair, cont’d.
2. Fur: inner coat of hair; provides insulation
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4. Types of Hair, cont’d.
3. Tactile hairs
(whiskers): found
on the head of
animals; helps
them sense their
environment
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5. Parts of the Hair
1. Cuticle
2. Cortex
3. Medulla
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6. Parts of the Hair
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7. Hair Cuticle
- outermost, protective layer of hair
- covered with scales
-scales always point toward the tip of the hair
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8. Scale Types
Cuticle scales look different for different types of animals
Mosaic Chevron
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9. Scale Types (cont)
Pectinate Imbricate
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10. Scale Types (cont)
Petal Diamond Petal
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11. Scale Types
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12. Scale Types
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13. Scale Types
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14. Hair Cortex
Gives hair its shape and color.
It has two major characteristics:
• Melanin
• Cortical fusi
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15. Hair Medulla
The size and pattern of the medulla could
be related to the thickness (or fineness
of the hair).
Medulla patterns:
• Continuous
• Intermittent or interrupted
• Fragmented
• Absent--not present
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16. Hair Medulla Patterns
Uniserial
Multiserial
Vacuolated
Lattice
Amorphous (without a distinct pattern)
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17. HUMAN MEDULLA
Human medulla may be continuous,
fragmented or absent.
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18. RABBIT MEDULLA
Rabbit medulla is different depending on the type
(location on the rabbit) of hair. The one to the left is
multiserial. The one to the right is a uniserial ladder
and is found in guard hair.
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19. Medullary Index
If the medulla takes up less than 1/3 of
the entire hair’s width, it is more
likely to be human. Other animal’s
medulla’s are much thicker.
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20. Hair Comparison
During the lab, you should record your observations of the
following:
• Color • Scale pattern
• Distribution and • Presence or absence
intensity of pigment of medulla
• Dyed hair has color • Medullary pattern
in cuticle and cortex • Medullary index
• Bleaching removes
pigment and gives
yellow tint
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