Blood Flashcards
What is blood
Viscous fluid that is pumped around the body by the heart and vascular system
What types of cells make up blood
Red blood cells
White cells
Platelets
plasma
How much blood is in the body
5 litres
What is the function of arteries
brings blood from the heart to organs and tissues
What is the function of veins
returns blood from the organs and tissues to the heart
What are arterioles, venues and capillaries
small blood vessels in the organs/tissues which have a small diameter and therefore maximise blood-tissue interaction
How quickly is all the blood pumped around the body
in 1 minute
What is the process of the blood when it travels through the heart
Vena cava -> right atrium -> right ventricle -> pulmonary artery-> lungs-> pulmonary vein-> left atrium-> left ventricle->aorta -> rest of the body
What are the functions of the blood
Hydration of tissues and organs Delivery of oxygen to tissues and organs Provision of nutrients to tissues and organs To fight infection Regulation of body temp and pH Distribution of endocrine hormones To prevent its own blood loss
What is the difference between paracrine and endocrine hormones
Paracrine hormones are secreted to adjacent cells
Endocrine hormones make use of the blood to transport to far away target hormones
Where do blood cell derive from
One common progenitor cell in the bone marrow called the multi potential haematopoietic stem cell
What are the two major lineages of blood cells
myeloid and lymphoid
What cells are found in the blood from the myeloid cell line
Megakaryocyte-> thrombocytes
Erythrocyte
Mast cell
Myeloblast-> basophil, neutrophil, eosinophil, monocyte -> macrophage
What cells are found in the blood from the lymphoid cell line
Natural killer cell
Small lymphocyte-> t lymphocyte, b lymphocyte -> plasma cell
What happens if incompatible blood groups are mixed
Antibodies react with antigens on the red blood cell membrane cause haemolytic which is red blood cell rupture
How are blood groups classified
based on different antigens present on the red blood cell membrane
What are the ABO blood groups classified by and what are the types
carbohydrate antigen on the red blood cell membrane
A, B, AB, O
What blood types are the universal donor and universal recipient of blood
Universal donor: O
Universal recipient: AB
What blood types are the universal donor and universal recipient of plasma
Universal donor: AB
Universal recipient: O
What are the symptoms of acute haemolytic reaction
Chills, fever Increased heart rate Constricting pain in chest Hypotension, uncontrollable bleeding Heat sensation in transfused vein Pain in lumbar region Hyperbillirubinemia
What classifies Rhesus blood group and what are the two types
transmembrane protein antigen present on the Red blood cell membrane
Rh+ and Rh-
What are the diseases of blood plasma related to
Bleeding
Thrombosis
Heriditary angiodema
Complement deficiency
What are diseases of blood cells
Haematological malignancies Sickle cell anaemia Thalassaemia Haemoglobinopathies Leukemia Thombocytopenia Infection
What is thombosis and what are the two types
Formation of a blood clot inside a vessel, blocking the circulation
Venous
Arterial
What is neoplasia
Process of uncontrolled cell growth
What are the two classes of genes involved in neoplasia
Oncogenes
Tumour suppressor genes
How are haematological malignancies classified
Blood cell lineage: myeloid, lymphoid
Location: leukaemia, lymphoma
Acute/chronic
Many subtypes
What is the lymphatic system
A drainage system which run in parallel with the blood system to remove toxins
What is anaemia
Low levels of haemoglobin
What causes acquired anaemia
Iron deficiency
Vitamin B12 deficiency
Folate deficiency
Blood loss
What causes iron deficiency
Diet Blood loss Infection Growth spurts Pregnancy
What is haemolytic anaemia
Bone marrow unable to replace red blood cells quickly enough as red blood cell life span is decreased
What are the three types of inherited haemolytic anaemia
Red blood cell cytoskeletal defects
Red blood cell enzyme defects
Haemoglobin defects
What is sickle cell disease
Point mutation in Hb
Distortion of red blood cells
Doesn’t absorb as much oxygen
What is a sickle cell crisis
Blockage of microvascularture as sickle cells join together
What is thalassemia
Large deletions of a-globin
or
Point mutations in the B-globin gene
What are the different types of bleeding
Spontaneous
Induced
Major
Minor
What is an abdominal aortic aneurysm
Progressive dilation of the abdominal aorta inferior to the renal and superior to the iliac arteries
High risk of aneurysm if becomes too large
What are primary causes of spontaneous bleeding
coagulation factor deficiency or haemophilia
Vitamin k deficiency
Thrombocytopenia
What causes vitamin K deficiency and what can reverse it
malabsorption Occurs in liver disease Occurs in newborn infants Due to oral anticoagulant over dose Vitamin K administration
Why is Vitamin K essential for normal haemostasis
Plays a critical role in the formation of Gla-domains in key coagulation factors which bind negatively charged cell membranes
What is haemophilia A
Deficiency in factor 8
What is haemophilia B
Deficiency of Factor 9
What are the standard coagulation assays
Prothrombin time (PT Activated partial thromboplastin time (APTT)
What is prothrombin time
uses tissue factor as a trigger
measures the extrinsic pathway
prolonged PT in F7 deficiency
Used in INR monitoring of oral anticoagulants
What is activated partial thromboplastin time
Uses silica as a trigger
Measures intrinsic pathway
Prolonged in F8 F9 F11 and F12 deficiency
What is the inheritance pattern of haemophilia
X-linked recessive
What is Von Willebrand disease
Deficiency of vWF
What are the three types of von willebrand disease and what are their inheritance patterns
heterozygous (autosomal dominant) functional deficiency (autosomal dominant) complete deficiency (autosomal recessive)
What is Von Willebrand factor
Large multimeric glycoprotein
Stabilises F8
Involved in platelet adhesion and aggregation
Produced by endothelial cell in weibel-palade bodies
What is thombocytopenia
Loss of blood platelets
What is thrombasthenia
Dysfunction of blood platelets
What are the main processes involved in stopping bleeding
Vasoconstriction
Primary haemostasis: platelet activation and aggregation
Secondary haemostasis: Coagulation pathway activation
What is the primary haemostatic response
Platelets are activated by collagen and thrombin -> undergo a shape change -> clump together (aggregate) to forma coagulum
This alone is insufficient to stem bleeds
What is the secondary haemostatic response
Coagulation ( clotting)
Involves a cascade of proteolytic enzymes in the plasma that activate one another
Initial activation by tissue factor or contact activation
Produces a fibrin clot network
This alone is insufficient to stem bleeds
What is limited proteolysis
Protein is cut into smaller fragments by hydrolysis of peptide bonds
Very specific single cut in a single protein
What is the result of thrombosis
Tissue death ( ischaemia ), malfunction, pain or swelling of the organ or tissue affected
What are the structural differences of veins and arteries
Veins: large diameter, thin wall, thin tunica media, low pressure, valves
Arteries: small diameter, thick wall, thick tunica media, high pressure, no valves
What are the charcteristics of DVT
Under low blood flow
Develops around the valves in the deep veins
May lead to Pulmonary embolism
What are the charcteristics of Pulmonary embolism
Small part of DVT breaks off (embolus)
This travels via the veins, right atrium and right ventricle to the lungs
The embolus blocks an artery in the lung leading to lung tissue infarction
What are the risk factors for venous thrombosis
Immobilization surgery cancer pregnancy oral contraceptives genetic risk factors
What are the natural inhibitors of coagulation
Antithrombin
Tissue factor pathway inhibitor
Activated protein C
Protein S
What is activated protein C resistance
Factor V Leiden
Point mutation in the factor V gene which increases the risk of DVT
What is arterial thrombosis
Caused by atherosclerosis
Triggered by rupture of the atherosclerotic plaque
precipitating event in myocardial infarction and ischaemic stroke
What are the risk factors of arterial thrombosis
advanced age smoking diabetes hypertension cholesterol poor diet lack of exercise
How is arterial thrombosis treated
Statins
Antiplatelets: aspirin, anti aIIbB3, Anti P2Y
Fibrinolytic
Preventative measures:
Longterm anticoagulation: warfarin, direct thrombin inhibitors
Heparin
How is Venous thrombosis treated
Heparin
Warfarin
Direct thrombin inhibitors
