Module 4: Phys. Ev. Hair, Blood, And Fingerprints Flashcards Preview

Forensic Science SEG 1 > Module 4: Phys. Ev. Hair, Blood, And Fingerprints > Flashcards

Flashcards in Module 4: Phys. Ev. Hair, Blood, And Fingerprints Deck (27)
Loading flashcards...
1

1600s Antonio van Leeuwenhoek

-Developed first known microscope
-Had a single magnifying lens

2

1655 Robert Hooke

-Developed the first compound microscope
-Examined thin slices of cork
-Named cells
-Other scientists hypothesized that cells are a basic unit of life

3

1833 Robert Brown

-First scientist to publish findings on the cell nucleus
- Used plant cells
-Cells were recognized as building blocks of living tissue

4

1838 M. J. Schleiden

-Published a conclusion that all plant tissues had cells
-Therefore all plants arose from cells
-Cell division work was incorrect

5

1839 Theodor Schawn

-Extended cell theory to animals
-Cells are organisms
-All organisms consist of one or more cells
-Cells are basic unit structure for all organisms

6

1840 Albrecht von Roelliker

-Sperms and eggs are cells

7

1855 Rudolf Virchow

-All cells come from previous cells
-Contradicts spontaneous generation

8

1862 Louis Pasteur

-Supported the theory that cells come from other cells

9

Hair Morphology

The form and structure of hair
-Samples typically collected from diff. areas of the scalp and pubic areas
-Pulled or cut off from skin line
-To ensure that unique form and color variation Is available
-See if hair is dyed or bleached
-Avg. hair growth at 1cm per month
-Race can be determined
-Pigment distribution
-Texture
-Cross section shape
-Can tell if hair fell out or was pulled
-Follicular tissue

10

Medulla

A set of cells that runs through a hair
-Used to determine if hair came from a person or animal

11

Nuclear DNA

DNA that is found in the nucleus of the cell
-Hair
-Found in Follicular Tissue

12

Mitochondrial DNA

Found in mitochondria of the cell
-Hair
-More common than nuclear DNA

13

A-B-O System

Categorizes blood into three different types
-Later expanded after Rh factor was discovered
-A, B, AB, O
-+ or - indicates the presence or absence of the Rh Factor
-Not used in linking blood to individuals, DNA is now used more commonly

14

Hemostasis

The process where blood forms clots

15

Vasoconstriction

The constriction of damaged vessels.
-Temporarily decreases blood flows and pressure
-Pressure on a bleeding wound

16

Platelet Plug Forms

When platelet sticks to the exposed collagen and become activated, which releases cells into the area creating a plug.

17

Clotting of Blood

Happens when reactions reinforce the platelet plug, which creates a plug
-Could also promote platelet adhesion and collection in a damaged area

18

Kastle-Meyer Color Test

Test that involves mixing a sample of a dried substance with chemical phenolphthalein and hydrogen peroxide
-If substance is blood, hemoglobin turns a deep pink
-Vegetable such as horseradish may turn pink

19

Hemoglobin

Protein which transports oxygen and gives blood the red coloring

20

Hemastix Strip

A color test in which distilled water moistens the strip and can determine if the substance is blood
-Will turn green in this case

21

Luminol Test

Where luminol is sprayed on surfaces and stains to see if there is blood. Blood emits luminescence when dark enough.
-Can even pick up traces of dried blood
-Has no effect after DNA tests

22

Precipitin Test

Used to determine if blood came from a human or an animal
-Human blood is put in an antiserum and will form a cloudy ring
-Can be used on dried blood that is 10-15 years old

23

Herbert L. MacDonell

Studied bloodstains and has critical observations about bloodstains.
-It is important to keep note of the texture of a surface of where the blood lands
-Blood splatters less when it hits a hard low porous surface
-Direction of travel can be seen
-Angles can be determined with the pattern, where the body was found and witness accounts
-Even without witness accounts, it can still be determined if a victim was standing
-Can also determine if the person was punched either once or more times

24

Latent Fingerprints

Fingerprints made by oil and perspiration

25

Visible Fingerepints

Created by when a surface is touched after the finger had contact with another substance
-Ink
-Blood
-Paint

26

Plastic Prints

Are made when the finger touches a soft material
-Soap
-Putty

27

Reflected Ultraviolet Imaging System (RUVIS)

Aims UV light at areas to find fingerprints