Haematology

Question 1

What is the process of Erythropoiesis?

Answer 1

The process of RBC formation/production

Occurs in bone marrow (where there many specialised stem cells)

Homeostatic mechanism

Question 2

What is the function of the blood?

Answer 2

1) transport- oxygen, nutrients, carbon dioxide, urea, hormones
2) regulation- body temp, pH, circulatory fluid volume
3) protection- preventing blood loss and infection

Question 3

What is plasma?

Answer 3

Straw-coloured sticky fluid

Question 4

What is haemostasis?

Answer 4

The stemming of blood loss following damage to a blood vessel

Effective at closing breaks in small vessels

Question 5

What 3 processes are involved in Haemostasis?

Answer 5

1) vascular spasm/construction of the damaged vessel
2) formation of a template platelet plug
3) clotting of blood (coagulation)

Question 6

Describe the process of vascular spasm…

Answer 6

Most immediate protection

Contraction of smooth muscle fibres in walls of damaged blood vessels (narrows vessel)- vasoconstriction- reducing blood flow to area

Question 7

Describe the process of platelet plug formation…

Answer 7

Platelets attach themselves to the ‘sticky’ lining of blood vessels causing ‘platelet plugs’ to form (caused by contact with collagen)- block minor bleeding

Platelet aggregation

Question 8

What is the function of Thromboxane?

Answer 8

Makes platelets sticky, allowing them to form a plug

Question 9

What is a platelet?

Answer 9

Cytoplasmic fragment

No nucleus/DNA

Question 10

What is the goal of the coagulation phase?

Answer 10

Convert fibrinogen present in blood to form fibrin

Question 11

What is the function of fibrin?

Answer 11

Entrap platelets and blood cells and seal the cut in the blood vessel

It’s formation involves many proteins- clotting factors (normal are inactive but are activated after injury)

Question 12

Describe the process of coagulation…

Answer 12

1) vessel is damaged/injured
2) substances released from damaged tissue results in formation of prothrombin activator
3) causes prothrombin to be converted to thrombin- calcium must be present for this to occur
4) thrombin converts soluble fibrinogen (manufactured in liver) into insoluble fibrin
5) fibrin forms network of threads that trap blood cells and platelets to form clot that halts bleeding

Question 13

What is a prothrombin activator?

Answer 13

Substance that leads to activation of the coagulation mechanism

Question 14

What is prothrombin?

Answer 14

Plasma protein manufactured in the liver with the help of vitamin K (co-factor))

Question 15

What is the process of fibrinolysis?

Answer 15

Process leading to the breakdown of a fibrin clot

Can also be achieved by thrombolytic or fibrinolytic agents

Question 16

What is the function of anticoagulant medicines?

Answer 16

Reduce the ability of the blood to clot

Question 17

What is function of warfarin?

Answer 17

Interferes with the action of vitamin K

Question 18

What is the function of heparin?

Answer 18

Interferes so fibrinogen can’t be converted fibrin

Question 19

What is the function of vitamin K?

Answer 19

Vitamin used in the liver as a co-enzyme in the production of clotting factors including prothrombin

Question 20

What is the function of anti-platelet medicines?

Answer 20

Reduce the risk of clots forming in the blood

Reduces risk of having a stroke or heart attack

E.g. aspirin

Question 21

What are the 6 functions of plasma proteins?

Answer 21

1) albumin (made in liver)- it’s negative charge helps control osmotic pressure of blood
2) transport
3) antibiotics- y globulins
4) contribute to viscosity of blood
5) buffers
6) involved in blood clotting