Hair analysis - Forensic's blog

General characteristics of Human Hair

1	Colour:	White, blonde, light brown, gray brown, dark brown, gray, black, auburn, red.
2	Reflectivity:	Opaque, gray, translucent, transparent, auburn, clear.
3	Length:	Fragment, 1”, 1-3”, 3-5”, 5-8”, 8-12”, 12-18”, 18-30”, segment.
4	Diameter:	20-30 um, 30-40 um, 40-50 um, 50-60 um, 60-70 um, 70-80 um, 80-90 um, 90-100 um, 100-110 um.
5	Spatial Configuration:	Undulating, kinky, curly, wavy, curved, straight, sinuous
6	Tip:	Singed, uncut, tapered, rounded, sharp cut, cut at angle, frayed, split, crushed, broken.
7	Base:	Cut, damaged, pigmented, clear, enlarged, tapering, broken.
8	Root:	Stretched, absent, bulbous, sheathed, atrophied, follicular, wrenched.
9	Cross-section:	Polygonal, oval, round oval, undulating, round.
10	Pigment:	Absent, non-granular, granular, multicolour, chain, massive (clumped), dense, streaked, opaque.
11	Medulla:	Absent, sparse, scanty, fractional, broken, globular continuous, irregular, double, cellular.
12	Cortical fusi:	Absent, few, abundant, bunched, linear, central, periphery, roots.
13	Cortical cells:	Brittle, damaged, fibrous, cellular, invisible, fusiform, ovoid bodies.
14	Cosmetic Treatment:	Bleached, rinsed, natural, dyed, damaged.
15	Cuticle:	Ragged, serrated, looped, narrow, layered, wide, cracked, absent, clear, dyed.
16	Scales:	Flattened, smooth, level, arched, prominent, and serrated.

Morphological Characteristics of Human Hair for Racial Determination

General characteristics of Human Hair from Different Sites

Scalp	Head hair, 100 – 1000 mm long, 25-125 um diameter, 0.4 mm/day growth; small root, tapered tip, little diameter variation, various medullation, often with cut tips, may artificially treated.
Pubic	Pudental, 10 – 60 mm long, coarse diameter and prominent diameter, variation and buckling, broad medulla, follicular tags common, asymmetrical cross section twisted and constricted, may be straight, curved or spirally tufted.
Vulvar	Secondary pubic hair, finer and shorter than pubic hair, may be abraided.
Chest	Pectoral, moderate to considerable diameter variation, long fine arch-like tip, usually longer than pubic hair.
Beard	Facial hair, very coarse, 50-300 mm long, large root, irregular structure, often triangular cross section, complex medullation, blunted or razor cut tips, grows 0.4 mm/day.
Axillary	Arm pit, 10-50 mm long, grows 0.3 mm/day, coarse, blunt tip, abraided or frayed, usually straighter than pubic hair, many cortical fusi, sometimes yellowed and bleached.
Eyebrow	Superciliary, 1 cm long, 0.16 mm/day growth, curved, relatively coarse for length, smooth curve with punctate tip and large medulla.
Eyelash	Ciliary, less than 1 cm long, short curved pointed hair.
Limb	Leg and arm hair, 3-6 mm long, fine tips, irregularly medullated, often indistinctly, slightly pigmented.
Ear	Tragi, pinnae, down
Buttocks	Anal hair, short blunted and abraided hair.
Nose	Similar to facial hair.

General Differences between Human Hair and Animal Hair

Feature	Human Hair	Animal Hair
Colour	Relatively consistent along shaft	Often showing profound colour changes and banding
Cortex	Occupying most of the width of shaft greater than medulla	Usually less than width of medulla
Distribution of pigment	Even, slightly more towards cuticle	Central or denser towards medulla
Medulla	Less than one-third width of shaft. Amorphous, mostly not continuous when present	Greater than one-third width of shaft. Continuous, often varying in appearance along shaft, defined structure
Scales	Imbricate, similar along shaft from root to tip	Often showing variation in structure along shaft from root to tip

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