Trace Evidence I: Hair and Fibers

Flashcards covering key concepts of trace evidence related to hair and fibers, including definitions and features of each component.

Trace Evidence

The most common type of physical evidence analyzed in a laboratory, including hairs, fibers, paints, glass, and soil.

Hair Follicle

An organ from which hair grows, consisting of a root and a bulb embedded in it.

Morphology

The study of the form and structure of organisms, used to describe the characteristics of hair.

Cuticle

The outer layer of the hair shaft that is scale-like and points toward the tip of the hair.

Cortex

The main body of the hair shaft that contains pigment granules which determine hair color.

Medulla

The central canal running through the hair shaft; its structure varies between humans and animals.

Anagen Phase

The initial stage of hair growth where the follicle actively produces hair; the root appears flame-shaped.

Catagen Phase

The transitional phase between the anagen and telogen phases of hair growth; the root appears elongated.

Telogen Phase

The final stage of hair growth where the hair falls out; the root takes on a club-shaped appearance.

Follicular Tag

Translucent tissue surrounding the hair's shaft near the root, which may contain DNA.

DNA analysis

A method used to individualize a hair sample, especially from a follicular tag.

Microscopic Hair Comparisons

An examination process that compares hair samples based on morphological characteristics.

Polymers

Large macromolecules made up of repeating units (monomers), important in the analysis of fiber evidence.

Natural Fibers

Fibers derived from plants and animals, such as wool, cotton, and silk.

Synthetic Fibers

Fibers manufactured from synthetic chemicals, including nylons and polyesters.

Microspectrophotometer

An instrument that combines microscopy and spectrophotometry to analyze fibers.

Medullary Index

The ratio of the diameter of the medulla to the diameter of the hair shaft, which helps distinguish between human and animal hair.