Chapter 10: Hairs & Fibres Flashcards
Hair is what type of evidence?
Physical evidence
Are you able to trace human hair back to the head it was on through morphology?
No
What is another way to individual human hair?
Characterizing the DNA
Hair samples from a crime scene are accompanied by what, when being sent to the lab?
Standard/reference samples
How can hair provide a strong corroborative evidence?
Can place an individual at a crime scene
Where does hair grow from?
Hair is an appendage of the skin that grows out of the hair follicle
What are the 3 phases of hair growth?
- Anagen
- Catagen
- Telogen
What are the 3 parts of the hair?
- Root/bulb
- Shaft
- Tip
What are the 3 layers of the shaft?
- Cuticle
- Cortex,
- Medulla – that is subjected to the most intense examination by the forensic scientist.
What is the cuticle of the hair?
The cuticle is the scale structure covering the exterior of the hair.
The scale pattern of the hair cuticle points in what direction?
Points towards the tip
How can you identify the species of hair?
The cuticle pattern
What is the cortex?
The cortex is the main body of the hair shaft.
How is the cortex important to forensics?
Its major forensic importance is the fact that it is embedded with the pigment granules that impart hair with colour.
Pigment granules are absent in what colour hair?
Grey hairs
What is the medulla?
The medulla is a cellular column running through the centre of the hair
What is the medulla index?
The medullary index measures the diameter of the medulla relative to the diameter of the hair shaft.