Cellular Components of Blood: Development and Function Flashcards Preview

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Flashcards in Cellular Components of Blood: Development and Function Deck (32):

What composes plasma?

- Plasma if the yellow/straw coloured liquid portion of blood (non-clotted) - Keeps cells in suspension - 92% water - 7% plasma proteins (albumin, fibrinogen, prothrombin) - 1% other substances - electrolytes, nutrients, hormones, gases, waste products. - Serum is plasma devoid of clotting factors (achieved by drawing blood in the absence of an anti-coagulant).


What is serum?

Serum is centrifuged blood to remove cellular components. Anti-coagulanted blood yields plasma containing fibrinogen and no clotting factors.


Where does haematopoeisis occur most commonly throughout a human lifespan? 

- Bone marrow only becomes major producer of RBC about half-way through lifetimes.

- Blood cells regulated by environment by stromal cells. 

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Which types of white blood cells are found in tissues? 

- Mast cells

- Dendritic cells

- Macrophages


Macrophages and Dendritic cells come from monocytes. 


Memorise the diagramatic overview of all blood cell progenitors. 

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How is haematopoiesis regulated? 

Production of blood and immune cells is tightly controlled by cytokines and growth factors. 

EPO - erythropoietin.

TPO - thrombopoeitin

IL - Interlukin

G-CSF - Granulocyte Colony Stimulating Factor

GM-CSF - Granulocyte Macrophage Colony Stimulating Factor

SCF - Stromal Cell Factor

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Explain the process of Erythropoiesis

- Erythropoiesis is the process of RBC formation.

- Occurs in the bone marrow.

- Body produces approximately 2.5x10^6 RBC every second.

Hypoxia is detected by kidney cells. 

Kidney releases EPO into blood.

Erythropoiesis is regulated by EPO binding to erythropoietin kinase receptor on progenitor cells. 


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Describe the structure of Haemoglobin (Hb). 

- 2 identical alpha chains & 2 identical beta chains. Each chain is associated with a Heme molecule.

- Fe molecule in centre

- Porphyrin ring linked to Iron as a co-factor

- Every RBC has around 280 million haemoglobin molecules and each haemoglobin molecule can carry 4 02. 


What is the lifespan of Red Blood Cells? 

120 days. 


How are erythrocytes recycled? 

- Aged cells are removed by macrophages of the spleen.

- Haemoglobin is seperated into Iron and Porphyrin ring. 

- Iron transported to bone marrow via transferrin for new RBC production

- Porphyrin ring excreted via digestive or urinary tract. 

(Bilirubin - Urine, Biliverdin - faeces)



What is the lifespan of platelets? 

7-10 days 


What is the process of platelet production? 

- Magakaryocyte (contains 64 copies of DNA)

- Megakaryocytes can produce around 5000 platelets, which occurs through its budding off mechanism. Membrane will extend but platelets will fragment off. 

- Thrombocytes are regulated by thrombopoeitein (TPO), produced by the liver and kidneys. 

 - They secrete PDGF in regulating blood vessels. 

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What are the five cardinal signs of inflammation? 

- Pain

- Heat 

- Redness

- Swelling

- Loss of Functioning


What's wierd about natural killer cells? 

They are part of the innate immune response despite being part of lymphoid progenitor. 

They have a relatively long life (around 14 days). They are essential for killing virally infected cells and comrpomise around 15% of WBCs. 


What are the characteristics and functions of Neutrophils? 

- Lifespan: 5.4 days

- 60-70% phagocytic

- Initiate inflammatory process. 


What are the characteristics and functions of Eosinophils? 

Lifespan: 2-5 days

2-5% of WBC

Phagocytic - protection against helminths. 


What are the characteristics and functions of Basophils? 

- Lifespan: 1-2 days

- 0.2% of WBC

- Involved in allergic reactions 


What are the characteristics and functions of monocytes? 

Lifespan: 1-7 days

2-10% of WBC phagocytic 


What is polycythemia vera and how would you test for it? 

Neoplasm in which the bone marrow makes too many red blood cells.

- It may also result in overproduction of white blood cells and platelets. 

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What is Polycythemia vera and what causes it? 

- Increased haemoglobin, PCV and RBC numbers

- 95% of cases due to mutation in the gene encoding the cell signalling Janus Kinase 2 (JAK2)

- Complications of PV include thrombosis and haemorrhage

Mutation in gene V617F (valine to phenylalanine mutation) results in constitutive activation of EPO/TPO receptors even in absence of EPO. 



What is essential thrombocythaemia (another type of Polycythaemia) 

- Normal Hb and WBC levels but increased platelet counts.

- Complications include thromboembolic events.

- JAK2 mutation present in 50% of all cases. 



What is Myelofibrosis/myelosclerosis? (another polycythemia) 

- Elevated WBC and platelet count

- 25% of cases preceded by PV

- 50% of cases have a JAK2 mutation.



What treatment options are available for those with Polycythaemia vera? 

Aims to maintain normal blood count

Venesection - removal of blood (about a 1 pint)

Chemotherapy -

Chemotherapy can suppress immune system in low doses, maybe that's how it works? Through inhibition of IL-2? Look this shit up? 


What are the most common systems for grouping blood? 

ABO and Rhesus


What are A and B antigens? 

Present on red cell membrane glycoproteins and glycolipids.


The major carriers of A and B on red cells are the abundant N-glycosylated glycoproteins, the anion exchanger (band 3) and the glucose transporter (GLUT1).


Glycosyltransferase structure is encoded by different genes


Type A: N-acetylgalactoaminyltransferase

Type B: galactotransferase

Type O (H): no transferase 


What is present on type A red blood cells? 



How can Rhesus Disease develop? 

Two genes encode this blood group:

- Most important is D

- Why is D antigen important?

- Because it is capabale of resulting in Rhesus disease. 

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Explain the Rh blood group system 

- 5 major Rh antigens - D, C, E, c and e - most immunogenic is D.

- Encoded by two genes: RHD and RHCE

- Individuals can be homozygous for RHD (2 copies) or hemizygous (1 copy). 

- All express D antigen on RBC

- Individuals where RHD is deleted have no expression of D antigen.

- Individuals are RhD+ or RhD-

- No anti-D antibodies present in blood 


How does Rhesus disease manifest? 

- 85% of population 

- Range in effect: mild anaemia of newborn to intrauterine death 18 weeks after gestation

- HDN is relatively rare - alleviated through routine antenatal serology and administration of Anti-D therapy

- Anti-D immunoglobulin will bind and neutralise any RhD+ cells preventing the development of maternal antibodies. 


Which blood group would make you a universal recipient and a universal donor? 

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Explain the process of agglutination. 

Agglutination is an immune response factilitated by antibody-antigen interactions.

Agglutination is detrimental in vivo.

This is not coagulation 

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Work out possible blood types of a baby based on mother and father's blood types. (or just memorise this diagram). 

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