Blood Video: http://www.youtube.com/watch?v=-fVDGu82FeQ

There is about 5L of blood in our bodies

Blood Constituents Liquid (55 %) Solids (45%) Plasma Red Blood Cells (approx. 45%) White Blood Cells (less than 1%) Platelets (less than 1%)

Due to their different densities, the constituents of blood can be separated by: Centrifugation

Order of increasing densities: Platelets Order of increasing densities: 1) plasma 2) White blood cells and platelets 3) Red Blood Cells

Plasma Yellowish tint 90% water Contains proteins, nutrients and waste Transports red and white blood cells, platelets, nutrients, antibodies, hormones and waste (urea and carbon dioxide)

Red Blood Cells Also known as erythrocytes A single drop of blood contains up to 250 MILLION red blood cells Do not contain a nucleus Doughnut shaped Life span of 100-120 days Contain hemoglobin

Hemoglobin Protein that gives blood its red colour Binds to oxygen in the lungs and transports the oxygen to other cells in the body that need it. When oxygen is bound to hemoglobin, it is a bright red colour Once the hemoglobin gives up its oxygen, the hemoglobin becomes brownish red in colour

White Blood Cells Also known as leukocytes Have a nucleus Come in different sizes, but are typically larger than red blood cells There is approximately 1 white blood cell per 650 red blood cells. However, during an infection the number increases They can live from a few days to several years

Functions of White Blood Cells Involved in the immune response Some neutralize bacteria, viruses or other harmful substances in the body They also rid the body of debris from dead or damaged cells.

Platelets Also called thrombocytes Not really cells, just small fragments of red blood cells No nucleus About 1 for every 20 red blood cells Maximum life span of 10 days

Function of Platelets Watch the video and write down the functions of platelets: http://www.youtube.com/watch?v=q8_nEMe00GU

Blood Types

These antigens that are present on red blood cells are also known as agglutinogens.

The antibodies are also known as agglutinins

So what happens when someone from group A receives a blood transfusion from someone from group B? Because the person with type A has Anti-B agglutinins (antibodies), when the type B blood enters the person’s body, the antibodies will react with the type B blood.

Who can receive blood from anyone? AB: because they do not have antibodies for A or B (otherwise they would attack themselves) and so any type of blood would be okay for them

Who can give blood to anyone? O: because they have no agglutinins on their surface, so even if the person receiving the blood has anti-A or anti-B antibodies, they will not interact with the O blood

The Rhesus Factor A person is either positive (has it: Rh+) or negative (doesn’t have it: Rh-) for this agglutinogen If you are positive, you can receive blood from someone who is positive or negative If you are negative, you can only receive blood from someone who is negative.

What blood type is most important for blood donor clinics? O- : because they can give to everyone

Current distribution of blood types in Quebec Rh Positive (85%) Rh Negative (15%) O 46% 39% 7% A 42 % 36% 6% B 9% 7.5 % 1.5% AB 3 % 2.5% 0.5%

Antigens/ agglutinogens Blood Group Antigens/ agglutinogens Antibodies/ agglutinins Can give blood to Can receive blood from AB A B O

Blood Group Antigens Antibodies Can give blood to Can receive blood from AB A and B None AB, A, B, O A B A and AB A and O B and AB B and O O