Haemopoiesis

Question 1

What is the lifespan of each of a) red cells, b) platelets, c) neutrophils?

Answer 1

Red cells = 120 days / platelets = 7-10 days / neutrophils = 7-8 hours

Question 2

What are the 3 main types of white blood cell?

Answer 2

Granulocytes, monocytes and lymphocytes

Question 3

What is the function of a) B cells, b) T cells, c) NK cells?

Answer 3

B cells = humoral immunity / T cells = cell mediated immunity / NK cells = anti-viral/tumour

Question 4

If production of blood cells in the bone marrow was to be switched off, in what order would certain cells stop being produced?

Answer 4

Neutrophils first, then platelets and then red blood cells

Question 5

What change occurs in neutrophils as they become more mature?

Answer 5

There is more segmentation of the nucleus

Question 6

What does it mean if a cell type ends in -blast? In adults, where would these cell be found?

Answer 6

Nucleated precursor cell / In the bone marrow

Question 7

What type of cell is a platelet precursor and is polypoid?

Answer 7

Megakaryocyte

Question 8

What are myelocytes?

Answer 8

Nucleated precursors between neutrophils and blasts

Question 9

All blood cell precursors begin as what?

Answer 9

Haemopoietic stem cells

Question 10

Haemopoietic stem cells divide into what?

Answer 10

Two daughter cells which are dissimilar - one is exactly the same as the parent cell (self renewal) and one is a progenitor cell

Question 11

What is meant be proliferation in terms of haemopoiesis?

Answer 11

An increase in cell number

Question 12

What is meant by differentiation in haemopoiesis?

Answer 12

Descendants commit to one or more lineages

Question 13

What is meant by maturation in haemopoiesis?

Answer 13

Descendants acquire functional properties and may stop proliferating

Question 14

Where do haemopoietic stem cells originate embryonically?

Answer 14

The mesoderm

Question 15

What is the first site of haemopoiesis in an embryo? Production where also starts at 6 weeks? Production where also starts at week 16?

Answer 15

Yolk sac / liver / bone marrow

Question 16

Where do arterioles in the bone marrow drain into?

Answer 16

Venous sinuses which open into larger central sinuses

Question 17

Describe venous sinuses in comparison to capillaries?

Answer 17

They are larger and have a discontinuous basement menmbrane

Question 18

Venous sinuses in the bone marrow are surrounded by what?

Answer 18

Adventitial cells

Question 19

What is the difference between red and yellow bone marrow? Which increases as we get older?

Answer 19

Red marrow is haemopoietically active, yellow marrow is fatty and inactive. As we get older, yellow marrow increases

Question 20

Describe what is meant by the myeloid: erythroid ratio?

Answer 20

The relationship of neutrophils and precursors to the proportion of nucleated red cell precursors

Question 21

What is the normal range of the myeloid: erythroid ratio?

Answer 21

1.5: 1 - 3.3.: 1

Question 22

What are some examples of when the myeloid: erythroid ratio may switch (i.e. more erythrocytes)?

Answer 22

Anaemia or haemolysis

Question 23

How do blood cells leave the bone marrow?

Answer 23

They pass through fenestrations (gaps) in the endothelium

Question 24

What happens to the venous sinuses in the bone marrow when there is release of red cells? What regulates this?

Answer 24

They dilate / adventitial cells

Question 25

What happens to the blood flow when there is release of red blood cells from the bone marrow?

Answer 25

Increased

Question 26

What are the routinely undertaken ways of investigating non-lymphoid mature cells? What is the less common way?

Answer 26

Blood count, cell indices, blood film / bone marrow exam

Question 27

What information is required to indicate the lineage/stage of development of lymphoid cells?

Answer 27

The expression of antigens

Question 28

What is the only lymphoid cell which is distinguishable by looking down the microscope?

Answer 28

Plasma cell

Question 29

What is the only way to tell apart a B/T/NK cell?

Answer 29

Immunophenotyping