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
Race | Diameter | Cross-section | Pigmentation | Cuticle | Undulation |
Negroid | 60 – 90 um | Flat | Dense & clumped | – | Prevalent |
Caucasoid | 70 – 100 um | Oval | Evenly distributed | Medium | Uncommon |
Mongoloid | 90 – 120 um | Round | Dense Auburn | Thick | Never |
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 |