2. Haemopoiesis

Question 1

What are the growth factors needed to stimulate stem cell differentiation into blood cells?

Answer 1

1. Erythropoietin (RBCs)
2. Colony Stimulating Factors (WBCs)
3. Interleukins (regulate cell growth)
4. Thrombopoietin

Question 2

What is extramedullary haematopoiesis?

Answer 2

When liver, thymus and spleen resume haematopoietic function

Question 3

Neutrophils

Answer 3

Phagocytes
High number indicates bacterial infection
Can’t be dyed
Polymorphonuclear

Question 4

Eosinophils

Answer 4

Stain brick red with eosin
Granules contain histamine, RNase and DNase
Combat viral and parasitic infection

Question 5

Basophils

Answer 5

Large cytoplasmic granules

Make and store histamine and heparin

Question 6

Stages in erythropoiesis

Answer 6

1. Proerythroblast
2. Basophilic erythroblast
3. Polychromatic erythroblast
4. Orthochromatic erythroblast
5. Reticulocyte
6. Mature RBC

Question 7

How are RBCs recycled?

Answer 7

Globin amino acids and iron reutilised

Haem excreted in bile

Question 8

What is needed for erythropoiesis?

Answer 8

Amino acids
B12 and folate
Iron

Question 9

Signs of anaemia

Answer 9

Fatigue and weakness
Pallor
Koilonychia
Angular stomatitis
Glossitis

Question 10

Types of anaemia

Answer 10

Hypochromic-microcytic
Normochromic macrocytic
Polychromatophilic macrocytic

Question 11

Hypochromic-microcytic

Answer 11

Most common

Due to blood loss, inflammatory diseases, cytotoxic treatments or chronic kidney disease or heart failure

Question 12

Megaloblastic anaemia

Answer 12

Macrocytic: RBCs are big, odd shape
Vit b12 deficiency
Lack gastric intrinsic factor, so more b12 is destroyed in stomach

Question 13

Haemolytic anaemia

Answer 13

Decreased life span of RBCs

Sickle cell anaemia or ABO/ Rhesus incompatibility

Question 14

Polycythaemia

Answer 14

Too many RBCs
Primary: mutation, increased viscosity
Secondary: Rate of prod adapts in response to low oxygen
Relative: Loss of fluid but not RBCs, dehydration

Question 15

What percentage of blood is plasma?

Answer 15

55%

Question 16

What is it called when the liver, thymus and spleen take over haemopoiesis?

Answer 16

Extramedullary haematopoiesis

Question 17

Describe the organelles within platelets

Answer 17

No nuclei

Have organelles and cytosolic enzymes for generating energy and synthesising secretory products

Question 18

How long do platelets remain functional for?

Answer 18

10 days

Question 19

What are platelets removed from circulation by?

Answer 19

Tissue macrophages

Question 20

How are platelets released from the spleen?

Answer 20

Sympathetically induced splenic contraction

Question 21

What are the benefits of the RBC’s biconcave shape?

Answer 21

Increases surface area

Thinness enables oxygen to diffuse rapidly

Question 22

What does FBC stand for?

Answer 22

Full Blood Count

Question 23

Why might you check the percentage of reticulocytes in the blood?

Answer 23

Useful index of erythropoietic activity in the bone marrow

Question 24

Why is a vitamin B12 deficiency slow to manifest?

Answer 24

Body stores 3 years supply of B12

Question 25

What is pernicious anaemia?

Answer 25

Caused by malabsorption of vitamin B12 due to lack of intrinsic factor

Question 26

What is polycythaemia vera?

Answer 26

Excess production of normal erythrocytes

Blast cells don’t stop producing RBCs when sufficient numbers have been produced