A&P2 week 4: blood types

If untreated, what is the result of a transfusion reaction?

Results in diminished oxygen-carrying capacity, impaired blood flow beyond blocked vessels, and accumulation of hemoglobin in kidney tubules which can lead to renal failure.

Which blood type is known as the universal donor? which is the universal recipient? Why are the terms misleading?

Type O negative is the universal donor, as there are no A antigens or B antigens, nor Rh antigen present. Type AB positive is the universal recipient as there are no anti-A or anti-B antibodies, and the Rh antibody is present in Rh+ and it not being present does not trigger immune system.

How are anti-Rh antibodies formed in Rh- individuals?

Not spontaneously. The rh- individual must first be exposed to the antigen, then the antibody will be formed.

Antigens of ABO and Rh blood groups cause vigorous transfusion reactions; what antigens are of less concern?

Other blood groups (MNS, Duffy, Kell, and Lewis) usually weak agglutinogens

Describe the immune response that is behind our method of blood typing.

The immune system recognizes cells not normally in the body from antigens. If an antigen is present, it stimulates the immune system to release antibodies to provide immunity against the specific antigen. Genetically determined proteins are found on the plasma membrane of RBCs. These special proteins are antigens - and what we refer to as red blood cell antigens.

Describe type A blood:

Type A blood is the presence of antigen A and antibody anti-B and also the absence of antigen B and antibody anti-A.

Describe type B blood:

Type B blood is the presence of antigen B and antibody anti-A and also the absence of antigen A and antibody anti-B.

Describe type O blood:

Type O blood is the absence of both antigen A and antigen B and presence both of anti-A and anti-B antibodies. Type O negative blood also lacks D antigen (rhesus factor/Rh-), and the lack of antigens make it the universal donor.

What happens if a type O person were given type A blood?

A transfusion reaction would occur, which is dangerous and sometimes fatal.

A person has type A- blood. If this person needed a blood transfusion, which types of blood could they safely receive?

A- and O- only.

What is done before blood transfusions to minimize problems? What can eliminate the need for minimizing problems?

Blood typing and cross matching before transfusion; autologous transfusions, or transfusions of one's own blood, drawn in preparation, can eliminate the chance of any adverse reaction.

What is Rh antigen also known as?

D

Of the markers that can be used to test for paternity, which marker provides the most useful statistical value?

D antigens

What is a transfusion reaction?

Donor's cells blood cells trigger immune response; donor cells are are attacked by recipient's plasma agglutinins, which causes agglutination and clogging of small vessels. Donor cells rupture and release hemoglobin into bloodstream.

Blood clots when anti-A antibodies are added, what is the blood type?

Either A or AB. B and O can be ruled out. To test blood type further, add the anti-B antibody. If it clots again, blood type is AB. If not, it is A.

What is an antigen comprised of?

Glycoprotiens.

A person has type AB- blood. What ABO antibodies are present in their blood?

Neither anti-A nor anti-B antibodies; if sensitized then anti Rh+ antibodies are present.

An Rh- mother and an Rh+ father have a Rh- child. The woman gets pregnant again; does she need to take any precautions with this baby? Why or why not?

No; not unless she had an accidental Rh+ blood transfusion before her second pregnancy. She would need to be exposed to the antigen to develop antibodies against it, and a fetus lacking the rh factor, as she does, would not trigger D antibody development.

What does it mean to be Rh positive? What is the frequency?

Rh+ indicates presence of D antigen. Any blood type can have it, or not. 85% Americans are Rh positive.

What happens when antigen A and antibody A are mixed?

The blood cells agglutinate

What is hemolytic disease of the newborn?

aka (erythroblastosis fetalis); occurs only in Rh- mothers carrying Rh+ fetus, is effectively treated with RhoGam serum. First pregnancy is usually fine, but delayed hemolytic reaction can occur in Rh- mothers who have developed antibodies (from previous transfusion or pregnancy). Can cause spontaneous abortion or impaired development and jaundice at birth.

Type O blood carries what antibodies?

both anti-A and anti-B

Antibodies produced in the blood plasma are ______ of those antigens on the RBC?

opposite

A person has O- blood. If this person were to donate blood, what blood types could they safely donate to?

All types.

A person has type B+ blood. What ABO and Rh antigens are present on the surface of their RBCs?

B antigens and D (Rh+) antigens are present.

Describe type AB blood:

Type AB blood is the presence of antigens A and B and absence of anti-A and anti-B antibodies. Type AB positive blood also has D antigen (rhesus factor), and the third antigen makes it the universal recipient.

What is an agglutinogen? How many agglutinogens have been named?

52 named Rh agglutinogens (Rh factors) C, D, and E are most common

What are the symptoms and treatment of a transfusion reaction?

Symptoms: fever, chills, low blood pressure, rapid heartbeat, nausea, vomiting. Treatment: supportive, preventing kidney damage, and giving fluids and diuretics to wash out hemoglobin.

Genetic blood types (in that blood type is expressed by genes) are determined by what?

Presence or absence of antigens on the red blood cells. These act by stimulating the immune system to produce antibodies.