Blood And Blood Componenets Flashcards
describe the constituents of the blood?
Made up of plasma (55%) erythrocytes (45%) leucocytes (less than 1%) and thrombocytes - platelets (less than 1%).
Women 3 to 5 litres
Men 4 to 6 litres
Children (30kg) just over two litres
Newborn 75-80ml
Preg women 5 to 6 litres
Outline production and function of erythrocytes
Production : starts in bone marrow as pluripotent stem cell, differentiates into pro erythroblast, haemoglobin is synthesised and nucleus expelled turning cell into reticulocyte, this then matures for 1-2 days in bone marrow before becoming erythrocytes.
(Juxtaglomerular cells in kidney detect low o2 and secrete erythropoietin into blood speeding up the maturation process.
Function : has four haem group containing iron that can transport oxygen and co2 biconcave shape for surface area faster diffusion small to fit through capillaries and flexible, no organelles so enough space.
Outline production and function of leucocytes
Produced by Leukopoiesis, hematopoietic stem cells in bone marrow differentiates into leukocytes.
Two types granulocytes (eg neutrophil kill bacteria or basophil attract other wbc), or argranulocytes (eg lymphocytes fight virus/tumours or monocytes become macrophage and engulf pathogens).
Outline production and function of platelets
Platelets Produced by hematopoiesis, fragments of megakaryocytes that split into platelets when pressed against sinusoid. Essential for blood clotting (hemostasis).
Blood vessel injury causes smooth muscle to contract platelets form a clot at wound area protein fibrin forms mesh to stop bleeding (coagulation) after vessel is healed fibrin removed by fibrinolytic.
Describe the four main blood types
A, B, AB, O, all have antigens except O with no antigens. AB is universal receiver as it can have all blood types without body attacking the blood as it has all antigens. Blood O is universal donor as it has not antigens so can be given to all blood types.
Outline the concepts of compatibility and incompatibility between donor and recipient
Donor blood must have same antigen to recipient blood or else the body will make anti antigens against donor blood which Coolidge be fatal for recipient as the immunological response is to attack the unknown blood.
Outline importance of rhesus factor in grouping blood during transfusion and during pregnancy
Rhesus blood can be inherited with three different alleles; C, D, E. If D is present on surface of RBC they’re Rh+ which is dominant to Rh-. If mother is Rh- and baby Rh+ RhD antigens from foetus mix and mother body makes anti D antibodies, due to molecular size these cross placenta and attack and haemolyse (break down of haemoglobin) the foetal erythrocytes carrying D surface antigen. Can cause fetal anaemia, hydrous fetaalis (liver swell and fluid build up).
