Hair And Fiber Flashcards
Cortex
The region of a hair located outside of the medulla containing granules of pigment
Cuticle
The tough outer covering of hair composed of overlapping scales
Hair follicle
The actively growing root or base of a hair containing DNA and living cells
Medulla
The central core of a hair fiber
Melanin granules
Bits of pigment found in the cortex of a hair
Trace evidence
Small but measurable amounts of physical or biological material found at a crime scene
Direct transfer
The passing of evidence, such as fiber from victim to suspect or vice versa
Fiber
The smallest indivisible unit of textile, it must be at least 100 times longer than wide
Natural fiber
A fiber produced naturally and harvested from animal, plant or mineral sources
Synthetic fiber
A fiber made from a man made substance, such as plastic
Secondary transfer
The transfer of evidence , such as fiber from a source to a person, and then to another person
Textile
A flexible, flat material made by interlacing yarn
Yarn
Fibers that have been spun together
Comparison microscope
A compound microscope that allows the side by side comparison of samples such as hair and fibers
What are the 3 different types of medullas of hair
Absent
Fragmented
Continuous
What are the 3 types of cuticles of hair?
Spinous
Coronal
Imbricate
What are 2 differences between animal and human hair?
In animal medulla is present for all animals and cuticle is spinous or coronal
In humans there can be no medulla and the cuticle is imbricate.
Which cuticle patterns are NEVER found in humans?
Spinous
What kind of evidence are fibers? Why
CLASS evidence because fibers can’t be assigned to a single person or thing.
What kind of evidence is hair?
Class evidence because it cannot be used to identify a specific individual.
Are rayon, polyester, nyon, acrylic, and olefin natural or synthetic fibers?
Synthetic fibers
Are wool, silk and cotton synthetic or natural fibers?
Natural fibers
What are other ways that you can analyze fibers
Burned test
Polarized light microscopy, or infrared spectroscopy and tests for solubility in different solutions
What are 2 major differences between synthetic and natural fibers?
All natural fibers come from nature however synthetic fibers are man made
All natural fibers tend to be expensive however synthetic fibers tend to be inexpensive
