Haemoatology Flashcards
What are blood clots composed of?
• Blood Clot is composed of a meshwork of fibrin fibers running in all directions and entrapping blood cells, platelets, plasma
Factor V Leiden Thrombophillia
Factor V Leiden is the name of a specific gene mutation that results in the development of the most common type of thrombophilia which is an inherited genetic disorder characterized by increased tendency to form abnormal blood clots.
People with factor V Leiden thrombophilia have a higher than average risk of developing a type of blood clot called a deep venous thrombosis (DVT).
DVTs occur most often in the legs, although they can also occur in other parts of the body, including the brain, eyes, liver, and kidneys.
Factor V Leiden thrombophilia also increases the risk that clots will break away from their original site and travel through the bloodstream
What is plasmin controlled by?
• Plasmin is controlled by: Anti-activators and Antiplasmin
Anaemia due to loss of RBCs
how does it happen?
Red blood cells can be lost through bleeding, which often can occur slowly over a long period of time, and can go undetected. This kind of chronic bleeding commonly results from the following:
Gastrointestinal conditions such as ulcers, haemorrhoids, gastritis (inflammation of the stomach), and cancer
Use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen, which can cause ulcers and gastritis
Menstruation and childbirth in women, especially if menstrual bleeding is excessive and if there are multiple pregnancies
Clotting cascade starting at thrombin
Thrombin changes fibrinogen to fibrin and it activates factor V, VIII and XII
Blood cells need capacity for renewal. This system involves what?
- proliferation of progeny stem cells
- differentiation and maturation of stem cells into the functional cellular elements
- in normal adults, the proliferation, differentiation and maturation of haematopoietic cells (WBC, RBCs and platelets) is limited to the bone marrow and widespread lympathic system and only mature cells are released into the peripheral blood
Functions of the blood
-Transporting fluids such as: Nutrients from digestive tract O2 from lungs Waste from cells Hormones
- Aids in heat distribution
- Regulates acid-base balance
What are WBCs (leukocytes) responsible for?
Phagocytosis – to engulf and absorb waste material and harmful microorganisms in the blood stream and tissues
Synthesis of antibody molecules
Inflammation process
Production of heparin – component found in lung and liver tissue which have the ability to prevent clotting of blood.
Heparin used in the treatment of thrombosis
Pathology of Anaemia due to the destruction of RBCs
When red blood cells are fragile and cannot withstand the routine stress of the circulatory system, they may rupture prematurely, causing haemolytic anaemia. Haemolytic anaemia can be present at birth or develop later. Sometimes there is no known cause. Known causes of haemolytic anaemia may include:
Inherited conditions, such as sickle cell anaemia and thalassemia
Stressors such as infections, drugs, snake or spider venom, or certain foods
Toxins from advancedliver or kidney disease
Inappropriate attack by the immune system (called haemolytic disease of the newbornwhen it occurs in the foetusof a pregnant woman)
Vascular grafts, prosthetic heartvalves, tumours, severe burns, exposure to certain chemicals, severe hypertension, and clotting disorders
In rare cases, anenlarged spleen can trap red blood cells and destroy them before their circulating time is up
what precursors are in the bone marrow?
The bone marrow contains both Erythroid (RBC) and leukocyte (WBC) precursors as well as platelet precursors
What is the primary site of haematopoeisis and when does it become that?
- bone marrow - located in spongy bone
- 6 months of gestation and then continues throughout life
What is coagulation?
What does it depend upon?
- Coagulation is the formation of fibrin meshwork (threads) to form a clot
- Coagulation of blood depends on the balance between pro-coagulants and anti-coagulants
- Prothrombin is the inactive form of thrombin
- The liver depends on vitamin K in the production of factor 2,7,9 and 10
How many types of anaemia are there?
How are they grouped?
There are more than 400 types of anaemia, which are divided into three groups:
Anaemia caused by blood loss
Anaemia caused by decreased or faulty red blood cell production
Anaemia caused by destruction of red blood cells
Anaemia due to reduced or faulty production of RBCs
Conditions that may cause this?
With this type of anaemia, the body may produce too few blood cells or the blood cells may not function correctly. In either case, anaemia can result. Red blood cells may be faulty or decreased due to abnormal red blood cells or a lack of minerals and vitamins needed for red blood cells to work properly. Conditions associated with these causes of anaemia include the following: Sickle cell anaemia Iron-deficiency anaemia Vitamin deficiency Bone marrow and stem cell problems include: Aplastic anaemia Thalassemia Lead exposure
What is fibrinolysis?
• Fibrinolysis is the break down of fibrin by naturally occurring enzyme plasmin therefore prevent intravascular blocking
