Lecture 8- Bleeding Disorders And Blood Types Flashcards
what do Thromboembolic disorders result from?
conditions that cause undesirable clotting, such as roughening of vessel endothelium or slow-flowing blood.
Thrombus
clot that forms in an unbroken vessel
if large enough, may block blood flow to tissues.
Embolus
A thrombus that breaks away from a vessel wall
will move through the circulatory system until it becomes stuck in a narrow blood vessel somewhere else in the body.
Anticoagulant drugs
Aspirin
Heparin
Warfarin
Prevent undesirable clotitng
What do bleeding disorders arise from?
Abnormalities that prevent normal clot formation
Thrombocytopenia
deficiency in circulating platelets and may result from any condition that suppresses or destroys red bone marrow.
It is treated with platelet transfusions.
How can impaired liver function be caused?
insufficient synthesis of procoagulant clotting factors
may be due to a shortage of vitamin K, or diseases such as hepatitis or cirrhosis.
Hemophilia
deficiency of clotting factors.
most commonly an X-linked recessive trait, but other genetic conditions can also cause clotting factor deficiencies.
It is managed clinically with transfusions.
Disseminated intravascular coagulation
situation leading to widespread clotting and severe bleeding
does not occur by itself but as the result of another condition, such as a complication of
pregnancy, septicemia, or incompatible blood transfusions.
has a mortality rate of 10-50%, with a higher rate of death for cases caused by infection.
Prothrombin time
Measures amount of prothrombin in blood
What does Platelet counts evaluate?
status of haemostasis system
Antigens
substances that trigger the body’s adaptive immune response.
In theory, things that do not belong inside the body and cause disease.
Antibodies
proteins produced by lymphocytes that target specific antigens.
Antibodies help the immune system by binding to pathogens to inhibit their functions
Affinity maturation
Once body encounters an antigen, it will make more of the antibody that binds it and refine the fit so that it can bind the antigen more effectively in the future.
part of how your immune system adapts.
What happens when lymphocyte maturation process fails?
Autoimmune disease
Immune system reacts to own tissues as an infection
Allergies
Immune hypersensitivities to non pathogenic foreign substances
Symptoms caused by overreaction of immune response
What antigens cause strong transfusion reactions?
ABO and Rh antigens
When is transfusion of whole blood used?
When blood loss is substantial or when treating thrombocytopenia
Antibodies and antigens present in type A
B antibodies
A antigens
Antibodies and antigens present in type B
A antibodies
B antigens
Antibodies and antigens present in type AB
No antibodies
A and B antigens
Antibodies and antigens present in type O
A and B antibodies
No antigens
Rh factor
referred to as “D” antigen, where the presence of the D antigen means that the person is Rh+ and absence of D antigen means person is Rh-
When does transfusion reaction occur?
if the antigens in the donor blood type are attacked by the recipient’s blood plasma antibodies resulting in agglutination and haemolysis of the donor cells.
Why is group O- the universal donor?
because their erythrocytes do not have A, B or D antigens.
Why is group AB+ the universal recipients?
They do not have anti-A, anti-B or anti-D antibodies
