Rest Of Blood (quiz 2) Flashcards
Thrombocytes
Platelets
-cell fragments
Function: protects against blood loss
-in buffy coat of whole blood (centrifuged)
-150000-400000 platelets per 1 microliter of whole blood
-2-4 micrometers in size
Hemostasis
sequence of events that stop bleeding
Hemostasis Events
- Vascular Spasm
- Platelet Plug Formation
- Coagulation
Hemostasis Event: Vascular Spasm
blood vessels constrict
Hemostasis Event: Platelet Plug Formation
Positive feedback mechanism
- Platelet adhesion- only a few platelets will show up at the site
- Platelet release reaction- chemicals will be released that will attract more platelets (increasing stimulus)
- Platelet aggregation- platelets will stick to each other and plug up the hole
Hemostasis Event: Coagulation
Blood Clot Formation
- blood changes from a liquid to a solid
1. Extrinsic pathway
2. Intrinsic pathway
3. Common pathway
Coagulation: Extrinsic pathway
- faster, fewer steps
- requires tissue factor produced by damaged tissue (outside of blood)
- requires Calcium ions
- makes prothrombinase enzyme
Coagulation: Intrinsic pathway
- slower, more steps
- does not require tissue factor, all factors are in whole blood
- requires Calcium ions
- makes prothrombinase enzyme
Coagulation: Common pathway
2 steps: (require Calcium)
- Prothrombin (inactive)——prothrombinase—> Thrombin (Active)
- Fibrinogen (soluble-dissolved in blood)—-thrombin–> Fibrin (active, insoluble)
Fibrin Clot
fibrin mesh + trapped formed elements (WBC, RBC, platelets)
Tissue Plasminogen Activator (TPA)
this helps convert plasminogen into its active form plasmin which will dissolve blood clots gradually over time
Anticoagulants
substances that prevent blood clotting
Thrombolytic Disorder: Thrombus
blood clot forms when it shouldn’t (undesirable blood clot)
Thrombolytic Disorder: Embolus
circulating blood clot
Thrombolytic Disorder: Embolism
blood clot blocks blood vessel
Antigen
glycoprotein that elicits an immune response
Agglutinogen
(self) antigen located on RBC surface
Antibody
protein that binds to an antigen
Agglutinin
antibody in plasma that reacts with an agglutinogen
Agglutination
clumping of blood cells due to antigen-antibody reaction
-results in transfusion reaction
-want to prevent this
hemolysis- split open
Blood Groups
chemicals on RBC surface (antigens on RBC surface)
-30 different blood groups have been identified
2 Blood Groups can cause transfusion reactions
- ABO blood group
- Blood type: A, B, AB, O - Rh Blood Group
A persons Blood Type is determined by?
The antigen on the RBC surface
- Type A- has the A antigen on RBC surface
- Type B- has the B antigen on RBC surface
- Type AB- has both A + B antigens on RBC surface
- Type O- does not have A or B antigens
A transfusion reaction (agglutination) occurs when….
donor’s RBC are attacked by recipient’s antibodies
A person has antibodies in plasma against…
antigens not present on own RBC
(a person has antibodies that are against the antigens that are not present on the RBC)
ex: type A blood type has B antibodies because type A blood does not have the antigen B it only has antigen A on RBC surface
What blood types can Type A blood receive and not receive?
Receives- A, O
Cant receive- B, AB (because its against antigen B)
What blood types can Type B blood receive and not receive?
Receives- B, O
Cant receive- A, AB (its against antigen A)
What blood types can Type AB blood receive and not receive?
Receives- A, B, AB, O
Universal Recipient
What blood types can Type O receive and not receive?
Receives- O
Cant receive- A, B, AB (it is against antigen A+B)
Universal Donor
Universal Recipient
Type AB blood
-receives all blood types
Universal Donor
Type O Blood
-each blood type can receive O blood
Rh Blood Group
Rh+: has Rh antigen on RBC surface
Rh-: blood type lacks the Rh antigen on RBC surface
Do people normally have antibodies in the plasma against the Rh antigen?
No, people normally DO NOT have antibodies in plasma against Rh antigen
-only if directly exposed
Blood typing
determination of a person’s blood type
-make sure the person who receives the blood is getting compatible blood
Cross-matching
donor RBCs mixed with recipient’s serum to determine compatibility
-trial run, take plasma from person receiving blood + takes donors blood to watch for clumping
no clumping = safe
ABO and Rh Blood Groups are reported..
reported together
ex: O+, B-, AB-
How would a hemolytic disease of the newborn occur?
Rh- mother is pregnant with her second Rh+ baby
- first pregnancy- Rh- mother carries a fetus of Rh+ blood
- Between pregnancies- she produces the Rh antibodies
- second pregnancy- has another Rh+ baby, only this time her Rh antibodies will go into the babies blood and attack the Rh+ antigens leading to hemolytic disease of the newborn
RhoGAM
removes old traces of the Rh antigen so the mother doesn’t produce antibodies
- prevents hemolytic disease of the newborn
- RhoGAM protects the second Rh+ baby
- take after delivery of the first pregnancy
