Hair Structure
Forensics
Hair Structure Cont.
Miscellaneous
100
These are fibrous proteins that form the main structure of hair
What is keratin
100
The actively growing root of a hair that contains DNA and living cells
What is the hair follicle
100

Head hair grows approximately 0.44 mm per day.  The length of hair would be ____ mm after 30 days of growth.

What is 13.2 mm (1.32 cm) (also 0.5 in)

100

Ethnicity from which kinky/curly, densely distributed pigment, and a cross-section that is flattened with moderate to small diameter is common

What is African ethnicity

200

Bits of pigment found in the cortex of hair

What are melanin granules

200

When hair can be considered circumstantial, biological, individual evidence.

What is contains the follicle

200

The youngest cells of the hair are near this 

What is the hair follicle or root

200

Determining that a hair is of European (Caucasian) ethnicity is a determination of 

What is the class of evidence

300
This is the outer layer of hair that has overlapping scales
What is the cuticle
300

Hair source with only imbricate scales

What is human hair

300

Hair growth slows and stops

What is Catagen Stage

300

Determined by measuring the diameter of the medulla and dividing it by the diameter of the hair. Animal is 1/2 or greater. Human is 1/3 or smaller.

What is the Medullary Index

400
This is the inner layer of hair that is made of keratin and contains pigment
What is the cortex
400

Small but measurable amounts of physical or biological material found at a crime scene

What is trace evidence

400
Medullary index for humans is usually this much
What is Less than 1/3
400

You lose approximately _____ to _____ hairs a day

What is 40 to 125

500
This is the inside layer of hair that runs down the cortex
What is the medulla
500

You can determine if someone is taking these from the chemical analysis (toxicology) of hair

What are drugs

500
For animal hair the medullary index is usually
What is greater than 1/2
500

Head hair grows about...

What is 0.44 mm per day (0.5 cm per month)

M
e
n
u