Lecture 16: Blood And Haemopoiesis

Question 1

What is the definition of haemopoiesis?

Answer 1

Production of blood cells and platelets in the bone marrow

Question 2

What is the process of haemopoiesis?

Answer 2

Stem cells in the bone marrow differentiate into different blood cells

Question 3

What is a hemocytoblast?

Answer 3

Multi potential hematopoietic stem cell

Question 4

What is the function of a hemocytoblast?

Answer 4

They can self replicate and differentiate further

Question 5

What are the 2 common progenitors that arise from hemocytoblasts?

Answer 5

Common myeloid progenitor and common lymphoid progenitor

Question 6

What are erythrocytes?

Answer 6

Red blood cells

Question 7

What are 4 key features of erythrocytes?

Answer 7

1. Bison cave shape to increase surface area for diffusion of gases
2. No nucleus to maximize oxygen holding capabilities
3. No mitochondria to ensure oxygen is not used up by erythrocytes
4. Haemoglobin to increase affinity of oxygen binding

Question 8

How does erythropoiesis work?

Answer 8

Erythroblasts starts off with large nucleus and large amounts of RNA but nucleus gradually shrinks and is removed along with most RNA, becomes reticulocyte and then becomes erythrocytes

Question 9

What are reticulocytes?

Answer 9

Final step before becoming a mature erythrocyte, once nucleus has been removed. Still has some RNA to make haemoglobin, which will disappear in 1-2 days

High amount of them can present in the blood when body is recovering from blood loss

Question 10

How does the body stimulate more RBC production?

Answer 10

Kidney senses tissue hypoxia (low O2) and increases secretion of erythropoietin

Question 11

What is erythropoietin?

Answer 11

Glycoproteins produced by kidney to increase levels of RBC, acts to stop apoptosis of erythrocytes progenitors

Question 12

What are granulocytes?

Answer 12

Sub group of white blood cells, they have granules in their cytoplasm

Question 13

What are the functions of granulocytes?

Answer 13

Mediate inflammatory reactions

Question 14

What are the 3 types of granulocytes?

Answer 14

Neutrophils, basophils, eosinophils

Question 15

What are neutrophils?

Answer 15

First responder and first line of defense against bacteria

Question 16

What are 3 key features of neutrophils?

Answer 16

• Multi lobular nucleus
• 3 types of granules
• most abundant granulocyte

Question 17

What are the 3 types of granules neutrophils contain?

Answer 17

Lysosomes
Matrix metalloproteinases (MMPs)
Gelatinase

Question 18

What are 4 functions of neutrophils?

Answer 18

1. Phagocytosis
2. Signalling and antigen presentation
3. Neutrophil extracellular traps
4. Respiratory burst

Question 19

What is the function of granulocyte-colony stimulating factor?

Answer 19

Acts on bone marrow to increase number of circulating neutrophils and increases the speed of neutrophils maturing in response to inflammation

Question 20

What are the functions of basophils?

Answer 20

Release histamine to trigger inflammation

Question 21

What are 2 key features of basophils?

Answer 21

Bilobed nucleus and purple granules

Question 22

What are the 2 substances that the granules in basophils contain?

Answer 22

Histamine and heparin

Question 23

What is the function of eosinophils?

Answer 23

Phagocytosis pathogens

Question 24

What are the 2 types of substances that granules of eosinophils contain?

Answer 24

Antihelminthic proteins

Cell component destroying enzymes

Question 25

What are the 2 key features of eosinophils?

Answer 25

2 nuclear lines and eosinophilia granules

Question 26

What are the 2 steps of granulopoiesis?

Answer 26

1. Nuclear condensation and lobular ion

2. Formation of granules

Question 27

What are the 2 kinds of agranulocytes?

Answer 27

Monocytes in blood and macrophage in tissue

Question 28

What are the 2 functions of monocytes and macrophage?

Answer 28

1. Phagocytose pathogens, cell debris and senescent cells

2. Present foreign antigens to lymphocytes

Question 29

What is the key feature of monocytes and macrophages?

Answer 29

Unilobular horseshoe shaped nucleus

Question 30

What is thrombopoiesis?

Answer 30

Production of platelets from megakaryocyte breaking down

Question 31

What is thrombooietin?

Answer 31

Substance that increases level of production of platelets

Question 32

What are the 2 functions of platelets or thrombocytes?

Answer 32

Stop bleeding and mediate haemostasis

Question 33

What are the 5 key features of platelets?

Answer 33

1. Smallest
2. Biconvex shale
3. No nucleus
4. Contain a lot of protein and clotting factors
5. Special receptors on surface that cause platelet aggregation

Question 34

What is lymphopoiesis?

Answer 34

Formation of lymphocytes

Question 35

What are the 3 types of lymphocytes?

Answer 35

B lymphocyte
T lymphocyte
Natural killer cell

Question 36

What are the 2 functions of B lymphocytes?

Answer 36

Produce antibodies, activate T cells

Question 37

Where is B lymphocytes produced and matured?

Answer 37

Maturation occurs in bone marrow and then in intestine, spleen and lymph nodes

Question 38

What are the 2 functions of T lymphocytes?

Answer 38

Kill virus-infected cells, neoplasticism cells and transplanted tissue

Activate B cells using IL4

Question 39

What is 1 key structural feature of t lymphocytes?

Answer 39

Large nucleus with small ring of cytoplasm

Question 40

What is the proliferation and activation of t lymphocytes caused by?

Answer 40

IL 2

Question 41

Where do T cells mature?

Answer 41

Start off in bone marrow and then migrate to thymus to mature, then migrate to secondary lymphoid organs where they will wait till activation

Question 42

What is plasma?

Answer 42

Supporting medium for all circulating blood cells

Question 43

What are 3 examples of plasma proteins?

Answer 43

Albumin, clotting factors, hormones