Blood and Blood spatter

agglutination

clumping of cells or molecules caused by an antigen-antibody reaction

antibodies

proteins secreted by WBC that attach to antigens

antigens

Foreign substance or cell that reacts with antibodies

lines of convergence (area of convergence)

two-dimensional view of the intersection of lines formed by drawing a line through the main axis of at least two drops of blood that indicates the general area of the source of the blood spatter

point of origin

three-dimensional view formed using lines of convergence and angles of impact of at least two different blood drops to identify the source and location of blood spatter

red blood cells

also known as erythrocytes; donut shaped cells that carry oxygen throughout the body

white blood cells

also known as leukocytes; cells that police the body by destroying foreign materials

platelets

also known as thrombocytes; cell component that is vital in blood clotting and blood vessel repair

satellite drop of blood

secondary drop formed when some blood breaks free from the main contact drop of blood

plasma

liquid portion of blood; composed mainly of water and proteins, wastes and nutrients

spikes

lines that extend from a main blood drop and are still connected to the blood drop

passive drops

circular blood drops that form from a dripping wound

Type O blood

when the RBCs contain no surface proteins

Type A blood

when the RBCs contain "A" surface proteins

Type B blood

when the RBCs contain "B" surface proteins

Type AB blood

when the RBCs contain "A" and "B" surface proteins

Kastle-Meyer test

a chemical test to determine if a stain is blood

ELISA test

test used to detect antibodies present in blood; used to determine if blood at the scene is human

presumptive test

test that establishes the possibility that a specific bodily fluid or tissue is present

confirmatory test

test that can identify a specific biological material

Low velocity spatter

Blood droplets from a heavier weapon that cause drops that are 4-6 mm in diameter

Medium velocity spatter

Blood droplets from stabbing or beating that are usually 1-4 mm in diameter

High velocity spatter

Blood droplets from gunshots or other high speed impacts that are less than 1mm in size and appear as a fine mist.

Swipe

transfer of blood onto a surface not already contaminated with blood

Wipe

when an object moves through blood that has not completely dried and moves, removes, or otherwise alters it

Arteries

blood vessels that move blood away from your heart under great pressure

Veins

blood vessels that carry blood back to your heart under lower pressure than arteries