27 terms

Hug Forensic Science Chapter 3 Hair

Bertino Forensic Science
STUDY
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class evidence
material that connects an individual or thing to a certain group. Example: a size 10 footprint.
comparison microscope
a compound microscope that allows the side by side comparison of samples, such as of hair or fibers
hair cuticle
the tough outer covering of a hair composed of overlapping scales
hair follicle
the actively growing root or base of a hair containing DNA and living cells
individual evidence
a kind of evidence that identifies a particular person, like DNA and fingerprints
keratin
a type of fibrous protein that makes up the majority of the cortex of a hair
medulla
the central core of a hair fiber
melanin granules
bits of pigment found on the cortex of a hair
trace evidence
small but measurable amounts of physical or biological material found at a crime scene
imbricate
flattened, overlapping scales commonly found in human and in many animal hairs.
continuous
medulla pattern that has one unbroken line of color
fragmented
medulla pattern where the line is unevenly spaced
pencil
you can use this common item as a model to remember the three hair parts
body temperature
hairs main purpose was intended to maintain this
drugs
you can determine if some one is taking these from the chemical analysis of hair
African
the hair from this race appears kinky, curled or coiled
Asian
the hair from this race has the largest diameter
hundred
you lose approximately one _____________________ hairs a day
epidermis
skin layer just below the skin surface
sebaceous gland
secrets oil to help keep the hair conditioned
Stages of hair growth
Anagen, Catagen, Telogen. Anagen is period of active growth, in catagen growth slows to a stop and hair is changing, telogen hair is dormant and may fall out.
1.3 cm
average amount of hair growth per month. This can be used to establish patterns in hair coloring or in drug use.
medullary index
Determined by measuring the diameter of the medulla and dividing it by the diameter of the hair. Animal MI is 1/2 or greater. Human is 1/3 or smaller.
animal hairs
have a wider diversity of cuticle patterns than human, larger and more varied medullas, and different cross-sectional shapes
nuetron activation analysis
(NAA) is a nuclear process used for determining the concentrations of elements in a vast amount of materials including hair.
dermis
Underlying, Inner Layer of the skin directly beneath the epidermis, is were the follicle is located
European
straight or wavy, small and evenly distributed pigments, varies in color, red, brown, blond or black

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