Red Cells 1

Question 1

What is erythropoietin?

Answer 1

A hormone that stimulates red blood cells in the bone marrow

Question 2

Where is erythropoietin made?

Answer 2

Kidneys and liver

Question 3

How long to RBCs live for?

Answer 3

120 days

Question 4

How does erythropoietin cause red blood cell maturation?

Answer 4

Proerythroblasts (immature RBCs) have erythropoietin receptors.
Erythropoietin binds to the receptors and cause them to mature into red blood cells.

They prevent immature RBCs from killing themselves via apoptosis.

Question 5

What stimulates erythropoietin production?

Answer 5

When the demand of oxygen in the kidneys isn’t being met the kidneys produce more.

Question 6

Which condition can cause low erythropoietin?

Answer 6

Chronic kidney disease - that’s why CKD can cause low RBCs and naemia.

Question 7

Where is haemoglobin created?

Answer 7

By stem cells.

Question 8

What is anaemia?

Answer 8

A reduction in red blood cells or in their haemoglobin content.

Its NOT a diagnosis.

Question 9

What are common causes of anaemia?

Answer 9

Blood loss
Increased destruction of FBCs
Lack of RBC production
Defective RBC production

Theres often high levels of haemolytic in the background.

Question 10

What do you need when creating erythrocytes (RBCs)?

Answer 10

Iron
copper
Folic acid
B12
Erythropoietin

Question 11

Where does RBC destruction happen?

Answer 11

The reticuloendothelial system

Question 12

Do RBCs have a nucleus?

Answer 12

They have a nucleus in the bone marrow during production but LOSE their nucleus when they leave the bone marrow.

Question 13

What are erythrocytes broken down into?

Answer 13

Globin - made into amino acids that are reutilised

Haem - Iron which is reutilised + bilirubin which is converted to bile in the gall bladder

Question 14

What are the forms of bilirubin?

Answer 14

Unconjugated before it reaches the liver

Question 15

What do high levels of unconjugated bilirubin mean?

Answer 15

Increased red cell breakdown

Question 16

When do you get conjugated bilirubin?

Answer 16

After it has been in the liver

Question 17

What is an immature RBC called?

Answer 17

Reticulocyte

Question 18

where is a common site of erythrocyte destruction?

Answer 18

SPleen

Question 19

What are the steps of erythrocyte maturation?

Answer 19

Erythroblast - reticulocyte - erythrocyte

Question 20

What does a high reticulocyte count in the blood show?

Answer 20

The blood is losing RBCs or it needs more

So the bone marrow is throwing out incomplete RBCs

Question 21

How long do RBCs look like reticulocytes for after being released into the blood?

Answer 21

24hrs

Question 22

What is the normal reticulocyte value in the blood?

Answer 22

1%

If you have 10% reticulocytes, this means that 10% of your blood has been lost and needs replaced

Question 23

What chains make up haemoglobin?

Answer 23

2 beta chains
2 alpha chains

There is a haem molecule associated with each chain.

Question 24

When is haemoglobin relaxed?

Answer 24

Its relaxed when it carries oxygen and has a tight binding structure when it has to give off oxygen

Question 25

When is more oxygen bound to haemoglobin?

Answer 25

Increase in pH
Decrease in temperature
Decrease in DPG

(Because less oxygen needs to be given off)

Question 26

When is less oxygen bound to haemoglobin?

Answer 26

Decrease in pH
Increase in temperature
Increase in CO2
Increase in DPG

(more oxygen needs to be given to tissues)

Question 27

How are the 2 alpha chains made?

Answer 27

From 4 alpha genes - 2 from mum and 2 from dad

Question 28

How are the 2 beta chains made?

Answer 28

From 2 beta genes - 1 from mum and 1 from dad

Question 29

What is the normal make up of haemoglobin?

Answer 29

97% HbA (2 alpha + 2 beta)
2% HbA2 (2 alpha + 2 delta)
1% HbF (2 alpha + 2 gamma)

HbF = foetal haemoglobin

Question 30

When is HbF replaced with HbA?

Answer 30

At 6 weeks