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Flashcards in Blood Cells And Haemopoesis Deck (18)
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Outline the process of haemopoesis

1) stem cell divides into two - one to replace original and one that will differentiate
2) haemopoetic progenitor will first differentiate into myeloid blast or lymphoid blast
3) the progenitor will differentiate jnto a certain cell type jnter the influence of a particular cytokine
E.g. Erythropoetin cause differentiation into a RBC


Describe the control of erythropoiesis

Detect fall in partial pressure of oxygen
Increase erythropoetin which stimukates maturation and release of red cells from marrow


Describe the structure of nuetrophil

Multilobed nucleus
Specialised for working in anaerobic (useful for damaged)


Describe the function of a neutrophil

Migrate out of circulation to site of infection
Imcreased production by G-CSF


Describe structure of eosinophil

Bi-lobed nucleus


Describe the function of eosinophil

Release cytotoxic particles to damage larger particles


Describe the function of basophil

Mediate acute inflmatory reactions using heparin and histamine


Describe the function of monocytes

Migrate to become macrophages in many organs
Capable of phagocytosis and interact with t cells


Describe function of B lymphocytes

Humorsl immunity. Stimulated by antigens, transform into plasma cells which secrete immunoglobulins


Describe the function of t lymphocytes

Express CD4 on surface (helper)
Can be killer
Permit transformation of b cells into plasma cells


Describe the structure of erythrocytes

Biconcave disc
4 globin chains (2alpha and 2 beta)
Each molecule carries haem
Flexible - to fit through small capillaries


Describe the function of erythrocytes

Carries O2 to tissues and CO2 to lungs
Maintain haemoglobin in its reduced (ferrous) state
Maintain osmotic equilibrium


Describe the structure of reticular cells

Synthesise reticular fibres and surround them with cytoplasm


Describe the function of reticular cells

Direct t and b lymphocytes to specefic regions with lymphatic tissues


Describe the structure of platelets

Small round blue particles
Produced by megakaryocytes
Complex surface membrane
Cytoplasm contains alpha and dense granules
Alpha contains fibrinogen and von willebands factor
Dense contains ADP and Ca2+


Describe the function of platelets

Clotting cascade
Adhere to damaged cell walls and aggregate together


Describe haemoglobin synthesis

Globin gene clusters on chromosome II and Ib
Globin chains synthesised indipendently and combine to form Hb
Switch from fetal to adult at age 3-6 months


Describe the process of red cell destruction and Hb catabolism

RBC broken down into haem, globin and iron
The haem is converted to billirubin snd transported to the liver bound to albumin
It travels down the bile duct to the intestine where is is converted to urobilinogen
Then travels to kidney and is excreted