Unit 5: Hair & Fiber Review
Identify each part of hair marked on the right
a
Tip
.
Shaft
Follicle
Root
b.
c.
d
.
:
2) The shaft is composed of what three layers?
Draw a diagram to illustrate.
Cuticle
Cortex
Medulla
3) The cortex contains granules. What are these granules and
what do they determine?
They are pigment granules that import color to hair.
4) Name, describe, and sketch the four types of medulla.
No
medulla
5) What does the medullary index measure? What is the
difference between human and animal hairs according to
medullary index?
It is an estimate of the width of the hair taken up by the medulla.
Generally, human’s medullary index values is less than 1/3.
Animal’s is ½ or greater
6) What the steps to take when examining a hair found at the
crime scene?
1) Determine whether the hair originated from a human or
animal.
2) If human, compare the hair with hair from victims and
suspects.
7) List four hair features to compare under microscope.
Pick four features out of many: cuticle shape, pattern, hair color,
pigment granules in cortex, medullar type, medullary index, hair
condition (treatment/removal)
8) Can the body area of a hair determined? Why not?/How?
Yes. Hairs from different body areas have different characteristics.
Head hair – longest; facial hair – coarsest with a blunted tip; pubic hair – lack of uniformity and
has distinctive buckling in the middle section; eyebrow – gradual curve with thicker than
normal medulla; arm/leg hairs – lack of uniformity in medullas, narrow tip.
9) Can the racial origin of hair be determined? Why not?/How?
Yes.
10) Is it possible to determine if a body hair was forcibly removed
from the body? Why not?/How?
Yes, forcibly removed hairs have more tissues around the root or
bended.
11) List the two analysis for examining hair evidence. What
result can investigators tell from the analysis?
If root/follicle presents, use DNA analysis  match
If no root/follicle, use microscopic analysis  probability
12) Can you distinguish between natural and synthetic fibers?
Why not?/How?
Yes, synthetic fibers are more uniform than natural fibers.
13) List two samples each for natural and synthetic fibers.
14) List four features you will look for with fiber evidence.
Fiber types, colors, fiber number, and fiber location.
15) Review the terminology of hair: morphology, hair
follicle, shaft, cuticle, cortex, medulla, and medullary index.