Blood Cells And Haemopoiesis Flashcards
Contrast the potential of white blood cells to mobilise, divide and transform, with that of cells derived from other organs of the body
Multipotent haemopoietic cells –> WBC (bone marrow or thymus)
Neutrophils, eosinophils, basophils, monocytes, lymphocytes
Outline the process of haemopoiesis, explaining how the cellular components of the blood are derived from stem cells
Proliferation: stem cell differentiates into two (one to replace the original one, one that differentiates)
Differentiation: haemopoietic cell divides to form either myeloid blast (RBC, WBC, platelets) or lymphoid blast (immunoresponse cells) depending on the cytokine
E.g. Erythropoietin –> RBC, whereas thrombopoietin –> platelets
Describe the structure and function of the following: erythrocytes and reticular cells, lymphocytes, monocytes, granulocytes or polymorphonuclear leucocytes (neutrophils, basophils, eosinophils), platelets
Erythrocytes - biconcave disc, 2a and 2b chains, carries O2 to tissues and CO2 to lungs
Reticular - synthesise reticular fibres and surround them with cytoplasm, direct the T and B lymphocytes to specific regions within the lymphatic system
Lymphocytes - deep staining nucleus, B = humoral immunity - immunoglobins, T = helper, killer, B –> plasma
Monocytes - kidney shaped nucleus, migrate to become macrophages in any part of body
Neutrophils - multi-lobed nucleus, phagocytosis, increased G-CSF
Basophils - bi or tri-lobed, granules, mediate inflammatory reactions using heparin and histamine
Eosinophils - bi-lobed, phagocytosis, release cytoxic particles
Platelets - blue particles produced by megakaryocytes, clotting cascade, adhere to damaged cell walls and aggregate together
State the normal lifespan of a RBC and explain how the structure of RBCs enables them to accomplish their various functions
120 days
Biconcave, flexible disk - facilitates passage through microcirculation
4 globin chains - each carries a haem molecule that can bind one molecule of O2
Describe the process of RBC destruction and catabolism
RBC –> Hb –> Heme –> Billirubin
In liver: billirubin –> bile duct –> stercobilin
In kidney: billirubin –> urobilinogen
