1. Human Blood Groups
Answers to Worksheet

2. 1. What is the difference between antigens and antibodies?
1. Antigens are substances normally composed of proteins that stimulate an antibody response or the production of antibodies. Antibodies are special proteins that are produced in response to the antigens.

4. 2. Explain what happens when a person receives the wrong blood type.
. Blood types have markers known as antigens attached to the cell membranes of red blood cells. Individuals with type A blood have an A marker, type B have a B marker, type AB has both an A and B marker and type O has no special marker. If a person with type O blood is given type A blood the A marker will stimulate the production of antibodies. These antibodies will attach themselves to the A marker (antigen) and this causes clumping which will clog capillaries and prevent oxygen from being delivered to cells. This can cause a significant amount of tissue damage and even death if not treated.

5. 3. What makes AB blood so different from type A and B and why are they known as the universal acceptor or recipient?
. Type AB blood contains both A and B antigens so they do not produce antibodies against these markers. Due to the fact that they do not produce these antibodies they can tolerate transfusions from all four blood types. This is why they are known as the universal recipient.

6. 4. Why can people with type O Blood only receive type O blood?
. Individuals with type O blood do not have any markers on the surface of the red blood cells so therefore they will produce antibodies against both A and B antigens. This means that they cannot receive any blood that contains either antigen so the only option is a transfusion of type O. However due to the fact that it does not contain any markers all other blood types can also receive type O so it is known as the universal donor

7. 5. What is the rhesus factor?
The rhesus factor commonly known as the Rh factor is another antigen found on the red blood cells. It is inherited and if you have the factor you are considered Rh positive and if you are lacking the factor you are known as Rh negative. The rhesus factor is attached as a positive or negative to your blood type. For example if you are type A you will either be A negative or A positive.

8. 6. Explain how the Rh factor can affect blood transfusions.
The Rh factor has an impact on donation mostly for those who are Rh negative. People who are Rh positive can receive either positive or negative blood but those who are negative can only receive negative blood. Our bodies do not have natural antibodies against the Rh factor but they can be produced in response to exposure. What this means is that if an Rh negative person is exposed to positive blood, the first time they will likely be okay but the body will now recognize the antigen and produce antibodies against it. The second exposure is when the antibody response would occur.

9. 7. What is fluosol?
Fluosol is artificial blood that contains fluorine and was developed in Japan. It carries both oxygen and carbon dioxide and has some benefits such as the ability to be stored for long periods of time, no need for expensive screening tests and it will not carry HIV or other viruses.

10. 8. Although artificial blood is not as good as real blood, what is its main value?
The main value in Fluosol is its ability to buy time for the individual who needs a transfusion until human blood can be administered. It can be very useful as a supplement to those who need to undergo multiple transfusions and also helps prevent an overload of iron.

15. Heart Valves

16. Path of Blood in the Heart
Oxygen depleted blood enters the right side of the heart through the inferior/superior vena cava.
Blood enters the right atrium and the atrium contracts.
The tricuspid valve opens and blood enters the right ventricle.
 The right ventricle contracts

17. The pulmonary semilunar valve opens and blood enters the pulmonary artery
The pulmonary artery carries the oxygen depleted blood to the lungs where the carbon dioxide is dropped off and oxygen is picked up.
Oxygen rich blood now travels back to the left side of heart through the pulmonary vein.

18. Blood enters the left atrium and the left atrium contracts.
 The bicuspid valve opens and blood enters the left ventricle.
 The left ventricle contracts.
 The aortic semilunar valve opens and the oxygen rich blood enters the aorta.
The aorta carries the oxygenated blood to the entire body.