human or animal
how can investigators determine whether a hair left at the scene is human or animal
the medullary index (how wide the medulla is)
the hair shaft is composed of 3 layers, name 2.
cortex, medulla, cuticle
how many phases does a human hair have
three
how does the usefulness of hair, in an investigation, change when hair is forcibly pulled from the head vs naturally shed
hair forcibly removed retains the hair follicle which contains DNA, while naturally shed hair does not
what about the cuticle can help determine a species
the scale pattern
of the three layers, which layer provides the color
cortex
which hair phase lasts the longest
anagen; usually lasts 6 years
what are some distinguishing morphological features when examining hair; name 2
color variations
length
medulla
origin
pigment distribution and shape
how does the medulla appear in an animal vs a human
animal is continuous or stacked while a human is continuous or interrupted
hair is an appendage of the skin, what organ does it grow out of
hair follicle
name the three phases of hair growth in order
anagen, catagen, telogen
what can stable isotope analysis tell an investigator
the geographic history, diet, and health status of the individual
what is the difference between hair and fur
hair will continually grow while fur has a maximum length
what about the hair follicle is different between human races
the shape
RANDOM QUESTION
how long do drugs typically stay in hair
90 days
what are some examples of natural fibers vs manmade fibers
wool, cotton, cashmere vs nylon, rayon, spandex