Bloody Notes

Circulation If wound spurts (up to 6 feet!) you hit an artery –Flows away from heart, and therefore under pressure –ex.: carotid, femoral, aorta If wound pools (up to 6 feet!) you hit a vein –Flows toward heart, valves don’t allow backflow –ex.: jugular

Bloody Facts Your body contains 12 pints of blood (think Ben & Jerry’s) Blood pressure: –Systolic is about 120 (pressure during pump) –Diastolic is about 70 (heart at rest) Daily body blood travel: about 12,000 miles Heart beats per year: 35 million Average amount pumped during life: 3 supertankers

Blood typing and Punnet squares Traits that are controlled by more than two alleles. Blood type in humans is controlled by three alleles (or versions of traits): A, B, and O Examples of blood type crosses in Punnet squares PhenotypeGenotype AAA or AO BBB or BO ABAB only OOO only

Blood Transfusions Blood can only be transferred to a body of a person who's immune system will "recognize" the blood. A and B are antigens on the blood that will be recognized. If the antigen is unfamiliar to the body, your body will attack and destroy the transfused blood as if it were a hostile invader (which can cause death). O is like a blank, it has no antigens. O is called the universal donor because a person can receive a transfusion from O blood without having an immune response AB is the universal acceptor, because a person with AB blood has both the A and B antigens already in the body, A and B blood can be transfused to the person (as well as O) and the body will recognize it and not attack. Blood type allows investigators to eliminate suspects, but not convict. How come? See handout for detailed information

Blood spatter What can one tell from size and shape of drops? –Velocity at which the blood was traveling –Angle at which blood traveled Cast offs: drops distributed from swinging weapon See handouts for more detailed information –Or check out this site (CAUTION, graphic blood images):

Blood detection at crime scene Investigators can spray Luminol about a room. When a black light shines on the surface, cleaned blood reveals itself

Blood Diseases and disorders

Sickle Cell Anemia: –Had by one in Americans, but one in 500 African Americans Description: Normal red blood cells are round like doughnuts, and they move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and shaped like sickles used to cut wheat. When these hard and pointed red cells go through the small blood tube, they clog the flow and break apart. This can cause pain, damage and a low blood count, or anemia.

Malaria The disease is caused by a protistan parasite of the genus Plasmodium Common in tropics Flu-like symptoms first, then coma and potential death

Cycle of malaria

Hemophilia Any of several disorders that impairs the body from controlling bleeding Very rare in females, what does that tell you?