ToB 20 Blood Cells and Haematopoiesis Flashcards Preview

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Flashcards in ToB 20 Blood Cells and Haematopoiesis Deck (53)
1

What is the life span of a Red blood cell?

~ 120 days

2

What is the lifespan of a platelet?

~ 10 days

3

What is the lifespan of a neutrophil?

~ 2-4 days

4

What is the lifespan of a lymphocyte?

Between 1 day - years

5

Where are RBC's, platelets and most WBC's produced?

Bone marrow

6

What organ removes blood cells from the circulation?

Spleen

7

Name the 5 main (flat) bones which contain red bone marrow:

1- Pelvis
2- Sternum
3- Ribs
4- Vertebrae
5- Skull

8

Red bone marrow has approximately what percentage of fat?

50%

9

What is the name of the cell from which all blood cells are derived?

Multipotential haematopoetic stem cell

10

What are the 4 types of granular cells?

1- Eosinophil
2- Neutrophil
3- Monocyte
4- Basophil

11

What is the difference between a monocyte and a macrophage?

Monocytes are the precursor of macrophages, and are present in the blood stream, while macrophages are present in the ECF

12

What are the 5 main functions of RBC's?

1- Carry oxygen to tissues
2- Maintain Hb in its reduced state
3- Carry Hb
4- Maintain osmotic equilibrium
5- Generate ATP

13

Why can't RBC's create protein?

No nucleus = no DNA = no mRNA = no protein

14

Why is it important that RBC's are biconcave?

1- Maximise SA:vol ratio, for quicker diffusion of O2 and CO2
2- Increase flexibility for passage through microcirculation

15

What is the diameter of a RBC?

8 um

16

What are the 2 configurations of a RBC?

Oxyhaemoglobin = R state (relaxed)
Deoxyhaemoglobin = T state (tight)

17

How would a decrease in pH affect the configuration of a RBC?

Promote T state = Deoxyhaemoglobin (Bohr shift)

18

How would a decrease in temperature affect the configuration of a RBC?

Promote R state = Oxyhaemoglobin

19

Describe the shape of the oxygen-dissociation curve:

Sigmoidal

20

What happens to the oxygen dissociation curve during the Bohr effect?

Curve shifts to the right

21

What is the Bohr effect?

When specific environmental changes: Decrease in pH, increase in CO2 and temp, affect the oxygen-binding affinity of RBC's, and promote the formation of deoxyhaemoglobin

22

Which globin genes predominate in an adult?

alpha and beta globins

23

Which globin genes predominate in a foetus?

alpha and gamma globins

24

When does the switch from gamma globin to beta globin occur?

~ 3-6 months after birth

25

Name the 2 main metabolic pathways in RBC's:

1- Embden Meyerhof pathway
2- Pentose Phosphate pathway

26

Which metabolic pathway allows RBC's to generate ATP?

Embden Meyerhof pathway

27

The Embden Meyerhof pathway metabolises Glucose to what?

Lactate

28

Which metabolic pathway allows RBC's to generate NADPH?

Pentose Phosphate Pathway

29

The Pentose Phosphate Pathway metabolises Glucose 6-phosphate to what?

Fructose 6-phosphate and
Glyceraldehyde 3-phosphate

30

What is the main function of the pentose phosphate pathway in RBC's?

Generate NADPH
to protect against oxidative damage (via Glutathione)

31

Cells in which organ detect a fall in pO2, resulting in Erythropoetin release?

Kidney (interstitial peritubular cells)

32

What is Erythropoetin?

Hormone produced and released from the Kidneys, which stimulates RBC maturation and release in bone marrow

33

Which hormone controls Erythropoesis, and where is it produced and released from?

Erythropoetin, from the Kidneys

34

Describe the negative feedback loop of Erythropoetin:

-Kidneys detect fall in pO2
-Kidneys increase production and release of Erthyropoetin
- Erythropoetin increases RBC maturation and release
- Kidneys detect rise in pO2
- Kidneys decrease production of Erthyropoetin

35

How is an old/damaged RBC broken down and excreted?

- Removed from circulation by spleen,
- Macrophage within Spleen breaks Haem into uncongugated bilirubin
- This converted to conjugated bilirubin in the liver
- Passes through bile duct into s. intestine
- Colonic bacteria deconjugate and convert to urobilinogen
- Absorbed and excreted by kidneys in urine

36

Define platelets:

Tiny fractions of blood cells produced by Megakaryocytes

37

Which hormone controls platelet production?

Thrombopoetin

38

In which organ are majority of platelets stored?

Spleen

39

What is the main function of platelets?

Formation of blood clot

40

How do platelets promote blood clot formation?

- Adhesion to connective tissue
- Aggregate together = platelet plug
- Specific phospholipid membrane receptors to activate clotting cascade

41

What 2 bodies are found within platelets?

1- Dense bodies
2- alpha granules

42

What do the alpha granules of platelets contain?

Glycoproteins

43

What do the dense bodies of platelets contain?

Serotonin, ADP, Catecholamines and Calcium

44

Neutrophil maturation is controlled (mostly) by which growth factor?

G-CSF

45

Which growth factor enhances the chemotaxis and phagocytosis time of neutrophils?

G-CSF

46

Neutrophils contain granules. What is the function of these granules?

Contain enzymes (Defensins, Lyzozymes, Lactoferrin etc) for use when phagocytosing pathogens

47

Name the 4 main phagocytic cell types contained within the Reticuloendothelial system:

1- Monocytes (circulation)
2- Macrophages (tissue)
3- Kupffer cells (liver)
4- Microglial cells (CNS)

48

What are the main organs in the Reticuloendothelial system?

Spleen, Liver and Lymph Nodes

49

Lymph Nodes are mostly found in which 3 locations?

- Armpit
- Neck
- Groin

50

Which granular cell mainly mediate allergic reactions?

Eosinophil

51

Where are T lymphocytes created?

Bone marrow

52

Where do T lymphocytes mature?

Thymus

53

T lymphocytes can mature into which 3 cell types?

- T helper cell
- NK cells
- T cytotoxic cells