General: Topic 21-30 Flashcards
(120 cards)
What is thrombocytopaenia?
(Having) a low number of platelets
What is the name / word for having a low number of platelets?
Thrombocytopaenia
What are the characteristics of platelet disorders?
- Coagulation time is increased or normal
- BT is increased
- PT /APTT is normal
- Platelet count if normal of low
What are the two types of thrombocytopathies?
- Congenital (rare)
2. Acquired (common)
What are the congenital types of thrombocytopathies?
- Membrane disorders (Glycoproteins deficiencies)
- Intracellular defects (Serotonin deficiency)
- Deficiency of Thromboxan synthesis (activate platelet aggregation)
- Von Willebrand’s disease
What are the acquired types of thrombocytopathies?
- Drug effects —> NSAIDs
2. Metabolic disorders (Uraemia, Diabetes mellitus)
What are the consequences of the acquired types of thrombocytopathies?
- Abnormal platelet adhesion
- Abnormal platelet aggregation
- Abnormal platelet contraction
- Abnormal platelet secretion
What is the name of the congenital form of thrombocytopaenia?
Werlhof disease
What type of disease is Werlhof’s disease?
It is an autoimmune disease that targets several platelet surface antigens. The result is thrombocytopaenia
What are the main types of acquired thrombocytopaenias?
- Impaired production of platelets (bone marrow failure)
2. Increased utilisation of platelets (in blood vessels)
What are some reasons for the decreased production of platelets (thrombocytopaenia)?
- Mycotoxins
- Chemical compounds (phenols)
- Leucosis
- Radiation
- Bracken fern poisoning
What are some reasons for an increased utilisation of platelets (thrombocytopaenia)?
- Idiopathic thrombocytopaenia purpura
- DIC
- Virus infection
What happens during Bracken fern poisoning?
There is a decreased number of thrombocytes (platelets)
What is the name of the congenital form of vasopathy?
Teleangiectasia
What are the acquired forms of vasopathy?
- Mechanical (e.g. forced coughing)
- Vitamin C deficiency (Scurvy)
- Allergic purpuras
- Symptomatic bleeding (bacterial toxins, effect of several viruses)
What are the characteristics of acquired vasopathies?
- Bleeding time is increased or normal
- Coagulation time is normal
- PT is normal
What is a thrombus?
A clot of blood formed intravasally
What is another word for blood clot?
Thrombus
What is an embolus?
A bit of a blood clot that is carried away from the main clot by the bloodstream
What is the name of a blood clot that is not attached?
Embolus
What is an embolism?
The occlusion of a blood vessel by an embolus
What is an infarct?
When there is local ischemic tissue necrosis due to inadequate blood flow
What does ischemia mean?
Restriction of blood supply to tissues, causing a shortage of oxygen needed for cellular metabolism. Generally caused by problems with blood vessels, sometimes caused by congestion (e.g. vasoconstriction, thrombosis, or embolism)
What is a macrothrombus?
A relatively large thrombus