haematopoiesis and cell breakdown

Question 1

what is the rate of cell production and cell destruction?

Answer 1

3x10^6/s

Question 2

Where does haematopoeisis initially occur and then where after

Answer 2

initially occurs in the yolk sac, then embryonic liver and then spleen

Question 3

Where does haematopoiesis only occur at birth

Answer 3

myeloid tissue in red bone marrow

Question 4

Where does haematopoiesis occur in healthy adults

Answer 4

proximal long bones, ribs, sternum, vertebrae

Question 5

What are features of bone marrow

Answer 5

• Thicker than blood
• delicate mesh of reticular tissue
• contains immature blood cells

Question 6

What percentage of bone marrow is pluripotent stem cells

Answer 6

0.05-1%

Question 7

What is bone marrow thicker than

Answer 7

thicker than blood

Question 8

What can be found in the bone marrow in reference to blood cells

Answer 8

Immature blood cells,monocytes
and adipocytes

Question 9

How many new blood cells does the bone marrow produce every day

Answer 9

Produces 100 billion newcells
every day

Question 10

What is bone marrow aspirate

Answer 10

liquid sample that contains fragments of bone marrow

Question 11

How can leukaemias be categorised

Answer 11

can be categorised by morphology

Question 12

What is a haemoblast

Answer 12

it is a Haematopoietic Stem Cell

Question 13

What are properties of haemoblasts

Answer 13

• There are very few of them
• They can self-renew
• They have the capacity to develop into different cell types

Question 14

What percentage of red bone marrow cells are haemoblasts

Answer 14

0.05-0.1% of red bone marrow cells

Question 15

What are the different cell types that haemoblasts can become

Answer 15

bone, cartilage and muscle

Question 16

Why is proliferation and differentiation needed

Answer 16

to produce a variety of mature blood cells with specialised functions from progenitor cells

Question 17

What is differentiation

Answer 17

the stepwise changes that occur over successive generations of cells that result in specialised function

Question 18

What are cells are of myeloid lineage

Answer 18

Erythroid series (red blood cells)

Granulocytic series (neutrophils, monocytes/macrophages, eosinophils, basophils)

Megakaryocytes (platelets)

Question 19

What cells are of lymphoid lineage

Answer 19

B and T lymphocytes and related cells

Question 20

What does erythropoietin do

Answer 20

stimulates RBC production

Question 21

What does thrombopoietin do

Answer 21

stimulates platelet formation

Question 22

What do cytokines do in respect to WBC formation

Answer 22

stimulates WBC formation

Question 23

What can myeloid stem cells develop into

Answer 23

• Colony forming unit – erythrocyte [CFU–E]
• Colony forming unit – megakaryocyte [CFU–Meg]
• Colony forming unit – Granulocyte Macrophage [CFU–GM]

Question 24

Explain the process for blood cell removal

Answer 24

1. Red blood cell death and phagocytosis occurs
2. splits RBC into heme and globin

3.on the globin route, globin broken down to amino acids which are reused for protein synthesis

4. on the Heme route, broken down to [Fe3+ + transferrin] and biliverdin.
5. on Fe3+ route, the complex goes to the liver and becomes ferritin and leaves the liver, becoming the initial complex again
6. Fe3+ dissociates from transferrin and travels to the red bone marrow.
7. Fe3+, Globin and vitamin B12 undergo erythropoiesis via stimulation of erythropoeitin
8. New red blood cells are formed
9. In BILIVERDIN route, biliverdin turns into bilirubin.
10. bilirubin travels to liver and then small intestine and then large intestine
11. in large intestine, bilirubin associates with bacterial enzymes to become Urobilinogen
12. Urobilinogen is broken down into Urobilin and Stercobilin
13. urobilin goes to the kidneys and is passed out in urine
14. Stercobilin goes through the large intestine and is passed out as faeces