Blood Type
List the four blood types from most to least common
O, A, B, AB
What type of evidence is blood type considered?
Class evidence
The smaller the angle, the more elongated it is
How does height affect the size of blood droplets?
The higher the height, the bigger the droplet diameter is.
Where are blood cells made?
In bone marrow
What is the significance of the Rh factor protein?
If present, it makes the blood type positive. If absent, makes blood type negative.
What is the device that separates blood into its components?
Centrifuge
What does BPA stand for?
Bloodstain Pattern Analysis
What is the difference between wipe and swipe bloodstain patterns?
Wipe- blood is already on a surface and an object passes through it
Swipe- blood is on an object and is transferred onto a surface
True or False: The fastest that free falling blood drops can travel is 25ft/sec.
True
What is an antigen? Why is it significant in blood typing?
Antigens are cell-surface proteins that help classify the different blood types based on the present proteins.
What is the first step that an investigator will do when seeing blood like material at a crime scene?
What is the difference between a passive bloodstain pattern and projected?
Passive- created from the force of gravity
Projected- caused by blunt force
What would cause medium velocity blood spatter?
Blunt object (fist, bat) or stabbing
What percentage does blood make up in your body fat?
8%
I am performing a blood typing test. There is agglutination in the A and Rh well, but not in the B well. What is the blood type?
A+
What is the function of platelets?
They form blood clots
What would cause low impact velocity blood spatter?
Injury (cutting finger while cooking dinner)
What would cause high velocity blood spatter?
Gun shot wounds or extreme force
What animals have blue blood that contain copper instead of iron?
Horseshoe Crabs
List the 8 possible blood types
O+, O-, A+, A-, AB+, AB-, B+, B-
What are the four components of blood?
-Plasma
-Platelets
-RBC
-WBC
What are 3 things that blood spatter can tell us?
- Type + velocity of weapon
- Number of blows with weapon
- Handedness of assailant (left or right)
- Type of injuries
- How long ago the crime was committed
What are the three things that make a blood droplet?
1. Parent drop
2. Satellite
3. Spine
The study of blood is called what?
Hematology