Warm Up Objective: Scientists will describe the integumentary system by analyzing fingerprints and hair. 1. What is the topic? 2. What will you be doing? 3. Why is this important? 4. How will you know if you have done well?

Warm Up Objective: Scientists will describe the integumentary system by analyzing fingerprints and hair 1. What is the topic? Integumentary system 2. What will you be doing? Analyzing fingerprints and hair 3. Why is this important? Understand more about ourselves; future career; criminology 4. How will you know if you have done well? Able to describe the integumentary system

Fingerprints Background Fingerprinting has been used as a tool to help solve crimes since the 19th century. Because no two people have the same fingerprints (not even identical twins), a fingerprint found at a crime scene is a useful way to match a suspect with the crime scene. Fingerprints are the tiny raised spiral and concentric patterns called ridges found on the tip of each finger. Fingerprints form before you are even born and remain unchanged during a person’s lifetime. They form from the pressure on the fingers from the baby touching and their surroundings. All of the ridges of fingerprints form patterns called loops, whorls, and arches. Every finger has a unique fingerprint.

Fingerprints Background Fingerprinting has been used as a tool to help solve crimes since the 19th century. Because no two people have the same fingerprints (not even identical twins), a fingerprint found at a crime scene is a useful way to match a suspect with the crime scene. Fingerprints are the tiny raised spiral and concentric patterns called ridges found on the tip of each finger. Fingerprints form before you are even born and remain unchanged during a person’s lifetime. They form from the pressure on the fingers from the baby touching and their surroundings. All of the ridges of fingerprints form patterns called loops, whorls, and arches. Every finger has a unique fingerprint.

Fingerprints ARCH

Fingerprints Loop

Fingerprints Whorl

Fingerprints Your Fingerprint   What type of ridge pattern does your finger show? How do you know?

Hair Hair strands found at a crime scene can often provide clues for investigators. Although hair analysis cannot pinpoint a suspect with 100% certainty, it can help eliminate persons of interest and provide clues as to who might have been present at the scene of a crime. At the microscopic level, hair can provide information about owner’s characteristics such as race, sex, and possibly age. Hair is composed of a protein called keratin. Keratin is the same protein that forms our nails and our outer layer of skin. Hair shafts are composed of three layers: the cuticle, the cortex, and the medulla. The cuticle is the outermost layer of the hair.

Hair Hair strands found at a crime scene can often provide clues for investigators. Although hair analysis cannot pinpoint a suspect with 100% certainty, it can help eliminate persons of interest and provide clues as to who might have been present at the scene of a crime. At the microscopic level, hair can provide information about owner’s characteristics such as race, sex, and possibly age. Hair is composed of a protein called keratin. Keratin is the same protein that forms our nails and our outer layer of skin. Hair shafts are composed of three layers: the cuticle, the cortex, and the medulla. The cuticle is the outermost layer of the hair.

Hair (Continued) When comparing hair samples, there are a number of microscopic characteristics associated with the cuticle, such as the thickness of the cuticle, the variation in the thickness, the presence of pigment, and the color. Also, the nature of the outer cuticle margin may be smooth, looped, ragged, or damaged. The cuticle covers the intermediate layer, called the cortex. The cortex is home to the pigment-containing granules responsible for hair color and contains many of the characteristics used in the microscopic analysis of hair. The organization, density, size, and distribution of the pigment granules vary greatly between racial groups, individuals, and even to a small extent within an individual.

Hair (Continued) When comparing hair samples, there are a number of microscopic characteristics associated with the cuticle, such as the thickness of the cuticle, the variation in the thickness, the presence of pigment, and the color. Also, the nature of the outer cuticle margin may be smooth, looped, ragged, or damaged. The cuticle covers the intermediate layer, called the cortex. The cortex is home to the pigment-containing granules responsible for hair color and contains many of the characteristics used in the microscopic analysis of hair. The organization, density, size, and distribution of the pigment granules vary greatly between racial groups, individuals, and even to a small extent within an individual.

Hair (continued) Finally, the innermost layer of hair is called the medulla. This layer may be continuous, discontinuous, fragmentary, or even absent. The diameter of the medulla is a useful characteristic in the identification and comparison process. In addition to the three anatomical regions of the hair, many other characteristics are useful in the microscopic comparison process, including: the growth stage of the hair, the diameter of the hair, presence of artificial treatment, any damage present, and any diseases and other hair abnormalities.

Hair (continued) Finally, the innermost layer of hair is called the medulla. This layer may be continuous, discontinuous, fragmentary, or even absent. The diameter of the medulla is a useful characteristic in the identification and comparison process. In addition to the three anatomical regions of the hair, many other characteristics are useful in the microscopic comparison process, including: the growth stage of the hair, the diameter of the hair, presence of artificial treatment, any damage present, and any diseases and other hair abnormalities.

Hair

Hair and Evidence analysis Pull a strand of your hair. Examine it with the hand lens and microscope. Draw what you see below and LABEL the medulla, cuticle, and cortex. Review the evidence. Who’s fingerprints and hair were at the crime scene? Explain how you know.

Stations Review Review the stations activity from Friday – Reader and Researcher Student volunteers to share Scribe and Solver