ICL 1.2: Bone Marrow

Question 1

Are platelets included in the bone marrow differential?

Answer 1

No because they’re evenly spaced throughout

Question 2

What is normal bone marrow made of?

Answer 2

Hematopoietic tissue and sinusoids that are supported by a network of fibers and cells called stroma

Question 3

What does hematopoietic tissue do?

Answer 3

Gives rise to all cellular components of the blood

It decreases in amount as we age 1% per year until you get down to 30%

Question 4

What what is the myeloid:erythroid ratio?

Answer 4

2:1 up to 4:1

Tells us about the relative portions of cells in the marrow

Question 5

What is the bone marrow stroma made of?

Answer 5

Cells: fibroblasts, macrophages, adipose cells, osteogenetic cells

Fibers: collagen and reticular fibers

Question 6

Which adult bones normally contain bone marrow?

Answer 6

Flat bones = pelvis

Long bones = femur

Question 7

Which bone marrow specimen is best for examining individual cell morphology?

Answer 7

Bone marrow aspirate smear

Question 8

How many RBCs are removed per day?

Answer 8

2x10^11 RBC/day removed

Question 9

Where are RBCs destroyed?

Answer 9

Spleen

Question 10

Where are RBCs made during 1st trimester?

Answer 10

Yolk sac

RBC made is called Hb Gower and Hb Portland because there’s zeta chains instead of alpha

Question 11

Where are RBCs made during 2nd trimester?

Answer 11

Liver

HbF is what’s made

Question 12

What kind of bone marrow does hematopoiesis occur?

Answer 12

Only in red marrow!

Vertebrae, ribs, sternum, skull, pelvis, proximal femur and humerus

Question 13

Where is RBC production during 3rd trimester?

Answer 13

Bone marrow

HbA is what’s made

Question 14

What types of Hb are present at birth?

Answer 14

50-50 HbF and HbA

At 6 months it normal adult levels of HbA (96%) and HbA2 (3%)

Question 15

What are the growth factors for stem cells?

Answer 15

SCF, c-KIT ligand, Flt3-ligand

Question 16

What are the growth factors for granulocytes?

Answer 16

GM-CSF

Question 17

What are the growth factors for eosinophils?

Answer 17

IL-5

Question 18

What are the growth factors for monocytes?

Answer 18

M-CSF

Question 19

What are the growth factors for magkaryocytes?

Answer 19

Thrombopoietin

Question 20

What are growth factors for B cells?

Answer 20

Flt3L

Question 21

What are the growth factors for T cells?

Answer 21

IL-7

Question 22

What are the growth factors for NK cells?

Answer 22

IL-15

Question 23

How is erythropoiesis regulated?

Answer 23

Oxygen deficiency —> erythropoietin production by kidneys —> stimulates RBC production in bone marrow —> causes restored oxygen level

Question 24

Where does erythropoiesis occur during adulthood?

Answer 24

Bone marrow

Question 25

What are the stages of erythropoeisis?

Answer 25

1. Stem cell 2. Pro-erythroblast 3. Basophilic erythroblast 4. Polychromatophilic erythroblast 5. Orthochromatophilic erythroblast 6. Reticulocyte 7. Mature erythrocytes

Question 26

Why are granulocytes named the way they are?

Answer 26

They have specific granules

Question 27

What two features characterize promyelocytes?

Answer 27

Size (large) Granulation (lots of granules)

Question 28

In granulocytes, which self stage is the first one to show differentiation?

Answer 28

Promyelocyte stage

Question 29

Which cell stage in the monocytes series has beautiful tissue paper nuclear folds?

Answer 29

Promonocyte

Question 30

What stages of lymphocyte development are visible in normal bone marrow?

Answer 30

Lymphoblastic and lymphocyte