Download Telogen - Ardsley Schools

Hair Analysis
What is Hair?
Hair=
• Appendage of skin
• Grows out of a hair follicle
• Root, Shaft and Tip
Layers of Shaft
Medulla
Cortex
Cuticle
Cuticle Layer
• Tough and Resistant Outer Layer
• Overlapping scales made of keratin
• Used for species identification
Casting to see scale pattern
Cortex Region
• Beneath Cuticle
• Contains pigment granules that give color
to hair
• Look at color, shape and distribution of
granules
Medulla Region
• Center Region of Hair
• Presence and pattern varies from person to
person and from hair to hair on an individual
Uniserial
Multiserial
Vacuolated
Lattice
Fragmented Intermittent Continuous
Amorphous
Medulla
• Human hairs generally have Fragmented
or Absent medulla
•
Exception:Mongoloid/Asian - usually
have continuous medulla
Roots
• Necessary for growth of hair
• Can tell the growth stage of hair:
– Anagen= Actively growing, root is flame
shaped
– Catagen= Slowed growth, root elongated and
shrunken
– Telogen= Hair growth ends, root clubshaped, hair falls out of follicle
Roots
Follicular
Tissue
Catagen
Anagen
Telogen
Hair: Comparative Studies
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Need comparative microscope
Need multiple hairs for comparison
Look at overall color, length and diameter
Medulla absent or present?
Distribution, shape, color intensity of
pigment granules in cortex
Hair: Comparative Studies
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Dyed Hair (Paint Roller)vs Natural?
Bleached Hair (Yellowish tint)
Time of Dyeing? (Hair grows 1cm/month)
Nits or fungal infections?
Hair: Comparative Studies
• Types:
– Scalp= uniform diameter and pigment
distribution
– Pubic= short, curly and diameter variations
– Facial=Coarse, triangular, blunt tips
Hair: Comparative Studies
• Race:
– Black= Tight curls, dense uneven pigment
distribution, flat to oval hair in cross section
– Caucasian= Straight or wavy, fine to coarse
pigments that are evenly distributed, oval to
round hair in cross section
Hair: Comparative Studies
• Age and Sex:
– Age and Sex Determination= Most No,
– Baby Hair short, thin and fine pigment
Hair: Comparative Studies
• Forcibly Pulled Hair
– See follicular tissue at root
• Isolate Nuclear DNA
• Telogen hairs not a good source for DNA
• Mitochondrial DNA
Hair: Comparative Studies
• Drug use/ Poisoning
Hair Collection
• Need control samples
• Need at least 50 scalp hairs from an
individual
• Need at least 20 pubic hairs from an
individual
• Need full length hair
Cut close to scalp, need minimal amount of head and body hair
• http://www.youtube • http://www.youtube
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• http://www.youbea
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