Haemotology

Question 1

What is erythropoiesis?

Answer 1

The process of red blood cell (RBC) production.

Question 2

Where does erythropoiesis occur?

Answer 2

In red blood bone marrow.

Question 3

What is the process of erythropoiesis?

Answer 3

• Stem cell in bone marrow mature.
• Slowly fill with haemoglobin.
• Once bright red; reticulocytes are ready to escape.
• Get into capillaries and slowly mature.

Question 4

What kind of mechanism is erythropoiesis

Answer 4

Homeostatis =

• involving receptor, controller and effectors.

Question 5

What is plasma made of?

Answer 5

• 91% water.

- 7% plasma proteins.

Question 6

What are the characteristics of plasma?

Answer 6

• Straw coloured.

- Sticky.

Question 7

What are the most common plasma proteins?

Answer 7

Albumin.

Question 8

Where is plasma albumin secreted?

Answer 8

Liver.

Question 9

Which part of the plasma albumin helps control the osmotic pressure of blood?

Answer 9

The negative charge.

Question 10

What is the functions of plasma albumin?

Answer 10

1) . Helps control blood pressure.
2) . Transport of substances =
- calcium carried by albumin.
3) . Antibodies (y-globulins).
4) . Increased viscosity.
5) . Blood buffers =
- solution resistant to changes in pH of blood (critical).
6) . Blood clotting.

Question 11

What different types of plasma proteins are there?

Answer 11

• Albumins.
• Fibrinogen.
• Globulins.
• Transferrin.

Question 12

What are the functions of blood?

Answer 12

1) . Transport =
- oxygen, nutrients, CO2, urea + hormones.
2) . Regulation =
- body temp, pH, circulatory fluid volume.
3) . Protection =
- preventing blood loss, preventing infection.

Question 13

What is haemostasis?

Answer 13

Halts blood loss following damage to a blood vessel.

Question 14

What are the 3 phases involved in haemostasis?

Answer 14

1) . Vascular spasm (constriction of the damaged vessel).
2) . Formation of a temporary platelet plug.
3) . Clotting of blood at the site of damage.

Question 15

Describe the vascular spasm phase of haemostasis?

Answer 15

• Immediate protection.
• Contraction of muscle fibres in blood vessel walls.
• Causing vasoconstriction.
• Reduces blood flow.

Question 16

Describe the platelet plug formation phase of haemostasis?

Answer 16

• Platelets attach themselves to the ‘sticky’ lining of blood vessels.
• Platelet plugs formed.

Question 17

Describe the clotting phase of haemostasis?

Answer 17

1) . Substance released from damaged cells.
2) . Production of prothrombin activator.
3) . Activator converts prothrombin to thrombin.
4) . Thrombin converts fibrinogen to fibrin.
5) . Platelets and RBC’s form a clot that prevents blood loss.

Question 18

What does a prothrombin activator do?

Answer 18

Converts prothrombin to thrombin.

Question 19

What does thrombin convert fibrinogen to?

Answer 19

Fibrin.

Question 20

What ion must be present for the conversions to occur (blood clotting)?

Answer 20

Calcium ions =

• Prothrombin –> thrombin.
• Fibrinogen –> fibrin.

Question 21

What is fibrinolysis?

Answer 21

Process that leads to the breakdown of a fibrin clot (blood clot).

• normal process.

Question 22

What is prothrombin?

Answer 22

A blood clotting protein (factor).

Question 23

What vitamin is needed for the synthesis of prothrombin?

Answer 23

Vitamin K.

Question 24

Where is vitamin K secreted?

Answer 24

In the liver.

Question 25

What would a deficiency of vitamin k lead to in relation to blood clotting?

Answer 25

More bleeding (inhibits blood clotting).

Question 26

What is the anti-platelet properties of aspirin?

Answer 26

Aspirin prevents formation of thromboxane (promotes blood clotting) by;

• binding to COX 1 enzymes –> which prevents platelet clumping.

Question 27

Which health issue would aspirin be used for?

Answer 27

Stroke or heart attack =

• because it inhibits blood clotting (thromboxane), reducing risk.

Question 28

Which enzyme generates thromboxane?

Answer 28

COX 1 =

• aspirin binds to it, inhibiting blood clotting.

Question 29

What are anticoagulants?

Answer 29

Medicines that reduce the ability of the blood to clot

• used for cardiovascular diseases/strokes.

Question 30

What are the 2 most common anticoagulants?

Answer 30

• Heparin.

- Warfarin.

Question 31

What is the function of warfarin?

Answer 31

• Interferes the action of vitamin K.

- Results in inhibiting the production of prothrombin.