1: Haemopoiesis

Question 1

What is haemopoiesis?

Answer 1

Production of blood cells

Question 2

What is the average life span of a red blood cell?

Answer 2

120 days

Question 3

What is the average life span of a platelet?

Answer 3

7 - 10 days

Question 4

What is the average life span of a neutrophil?

Answer 4

7 - 8 hours

Question 5

If the bone marrow is suppressed, which blood cells become deficient first?

Why?

Answer 5

Neutrophils

Shortest life span

Question 6

Which type of blood cell is polyploid?

Answer 6

Megakaryocytes

Question 7

What is unique about the cell division of haemopoietic stem cells?

Answer 7

Capacity for self renewal

One of the daughter cells with be a HSC identical to its mother cell

So they can divide forever

Question 8

What is meant by myeloid?

Answer 8

Re: malignancy - a bone marrow malignancy

Re: lineage - non-lymphoid i.e granulocytes and lymphoid cells

Question 9

Which germ layer do HSCs originate from?

Answer 9

Mesoderm

Question 10

By which week of life does bone marrow haemopoiesis start?

Answer 10

Week 16

Question 11

In children, which areas of bone marrow undergo haemopoiesis?

Answer 11

All of the bone marrow

Question 12

In adults, which areas of bone marrow undergo haemopoiesis?

Answer 12

Axial skeleton

Pelvis

Proximal long bones only

Question 13

From which site is a bone marrow biopsy carried out in

a) adults
b) children?

Answer 13

a) PSIS

b) Anterior tibia

Question 14

Apart from haemopoietic cells, what other cells exist in the bone marrow?

Answer 14

Fat cells

Osteoblasts

Osteoclasts

Fibroblasts

Question 15

Through which structures in bone marrow are newly produced blood cells released?

Answer 15

Sinusoids

Question 16

Blood enters the bone marrow via ___.

Blood cells enter the plasma, then the plasma re-enters the circulation via ___.

Answer 16

capillaries

sinusoids

Question 17

What is special about the basement membrane of bone marrow sinusoids?

Answer 17

Discontinuous

Allows blood cells to enters the plasma

Question 18

What are the gaps in the basement membrane of a bone marrow sinusoid called?

Answer 18

Fenestrations

Question 19

Bone marrow sinusoids have adventitial cells - what are the function of these cells?

Answer 19

Contain smooth muscle - dilate and constrict to increase/decrease blood flow

Question 20

What colour is

a) active
b) fatty, inactive bone marrow?

Answer 20

a) Red

b) Yellow

Question 21

What is the myeloid:erythroid ratio?

Answer 21

Ratio of neutrophils (and precursors) to red blood cell precursors

Question 22

The myeloid:erythroid ratio usually favours (myeloid / erythroid) cells.

Answer 22

myeloid cells

i.e more neutrophils than RBCs

Question 23

In which situation is the myeloid:erythroid ratio reversed?

Answer 23

Blood loss

Haemolysis

i.e situations demanding erythropoiesis

Question 24

What is the only way to figure out the type of lymphocyte you’re looking at on a blood film?

Answer 24

Immunophenotyping

looking at specific antigens expressed on their cell membrane

Question 25

How does immunophenotyping work?

Answer 25

Each lymphocyte has specific antigens on their cell membrane

Add specific antibodies with fluorescent tag attached and shine light on it

Target cells will light up