History and Function of Hair
The century when scientists began using hair as trace evidence in criminal investigation.
What is the 1800's (the 19th century)?
The club-shaped structure in the skin from which the hair grows.
What is the hair follicle?
This stage is the earliest stage and lasts approximately 1,000 days.
What is the anagen stage?
It has a medullary index of .50 or more.
What is an animal hair?
Hair is resistant to decomposition because of the double helices of the amino acids in keratin.
True
In the animal kingdom, THIS is the main purpose of hair.
What is regulate body temperature?
Keratin
What is the protein that the hair shaft is composed of?
This is the second stage when the hair stops growing and the follicle recedes.
It has a medullary index of 0.33 or less.
What is a human hair?
The hair of an individual does not vary depending on where it is located on the body.
False. There are 6 types of hair on the human body. 1) head; 2) eyebrows and lashes; 3)beard and mustache; 4) underarm; 5) body; 6) pubic
Secondary transfer
What is what happens when a hair left at a crime scene adheres to something and is transferred to a second location.
This is the largest part of the hair shaft in humans.
What is the cortex?
In this last stage, the hair follicle is resting and hairs are easily lost.
What is the telogen stage?
It has an imbricate cuticle.
What is a human hair?
A pigmented line broken at even intervals is called an interrupted medulla.
True
This is the number of hair follicles a human is born with.
What is 5 million?
The inner-most part of the hair shaft.
What is the medulla?
This is the number of hairs per day a human can lose.
What is 100?
These are the 3 recognized ethnicities of hair types.
What is European, Asian, and African?
The food you eat and the chemicals you put in your body can be found in your hair as it grows out.
True. You can measure how long its been since someone has metabolized something in their body. The closer to the root of the hair the more recently it has been ingested.
This is the type of microscope that a forensic scientist might use to observe 2 hairs side by side.
What is a comparison microscope?
This is what gives hair its color.
What are melanin granules?
This is what happens at the end of the telogen stage.
What is the blood supply reconnects to the follicle and another anagen stage begins?
This is the number of hairs that are collected for analysis by investigators.
What is 50?
Hair grows at a rate of 1.3 cm per month.
True. Measure the hair from the root to the tip and divide that number by 1.3cm to find out approximately how long ago something was ingested.