A&P - Chapter 27 (Part 4) Flashcards
Why are there no antibodies in the blood that are the same as the self antigen on the RBC?
It would cause agglutination and clot
What is considered an additional antigen?
Rh antigen
What does Rh antigen do?
Its what makes a blood type positive or negative
Rh positive
Rh antigen is present in plasma membrane of RBC
Rh negative
Rh antigen is not present in the plasma membrane of RBC
What system does Rh system have the same principles as?
ABO system
- avoids antibody/antigen reactions
What is important to consider in blood transfusions?
Rh antigens
What are naturally present in the plasma?
No anti Rh antibodies
When do anti Rh antibodies appear in the plasma of Rh negative people?
If Rh positive RBCs have been introduced into their bodies
What is crucial in blood transfusions in order to avoid agglutination?
Matching the appropriate blood types
What blood type is the universal donor?
O-
Why is O the universal blood type?
It has no antigens in their plasma membrane
What is the blood type for a universal recipient?
AB+
Why is AB+ the universal recipient blood type?
It has no anti-A or anti-B or anti-Rh antibodies in its plasma membrane
What blood type can be used in emergency situations?
O-
Erythroblastosis fetalis
The abnormal presence of erythroblasts in the blood
When does erythroblastosis fetalis most common occur? (4)
- When the mother is Rh-
- When then father is Rh+
- When the baby inherits the father’s Rh+ trait
- When the mother carries a second Rh+ fetus ***
What does not naturally occur in the plasma?
Anti-Rh antibodies
How do anti-Rh antibodies appear in the blood plasma?
If Rh+ blood cells are introduced into an Rh- persons body
What doesnt normally occur between the mother and baby during pregnancy?
Mixing of each others blood
- but it can happen (during devlivery)
What leads to erythroblastosis fetalis?
Agglutination of fetal Rh positive RBCs
What does the mothers immune system consider?
The baby’s Rh+ RBCs as a pathogen of sorts and so will make anti-Rh antibodies against them
What can anti-Rh antibodies do when they cross back through the placenta into the baby’s blood?
Destroy the baby’s circulating RBCs
Why are first born infants from first time pregnancies often not affected by erythroblastosis fetalis?
Because it takes the mother some time to develop the anti-Rh antibodies
- all babies she has afterwards who inherit the Rh+ trait from the father are at risk
How can erythroblastosis fetalis be diagnosed and prevented?
By administration of a protein called RhoGAM
What does RhoGAM do?
Prevents the mother’s body from forming anti-Rh antibodies
What substance is released when RBCs are destroyed/broken down?
Bilirubin
What does bilirubin do?
Turns the baby yellow
- jaundice
