Developmental Hematology

Question 1

The hematopoetic stem cells which lead to all blood formed elements have maximum (1) ability but are only minimally (2) and tend to not divide as quickly as more differentiated cells

Answer 1

1. self-renewal

2. differentiated

Question 2

When stem cells divide they usually divide into?

Answer 2

a stem cell which remains pluripotent and a second cell which can differentiate along a more specific lineage

Question 3

Stem cells express (1) and respond to (2)

Answer 3

1. CD34 and c-kit

2. stem cell factor (SCF) and IL-6.

Question 4

The pluripotent stem cell can differentiate either along the (1) pathway

Answer 4

1. lymphopoetic or myelopoetic

Question 5

In the lymphopoetic pathway, cells are initially (1) positive and later B cells develop surface immunoglobulin which switches class from (2) to (3)

Answer 5

1. CD34 and TdT (terminal transferase)
2. IgM
3. IgG or IgD

Question 6

The most differentiated B cells are (1) cells which produce large quantities of specific clonal immunoglobulins.

Answer 6

1. plasma

Question 7

In the myelopoetic pathway, the precursors can differentiate into (1) in response to (2) or (3) in response to (4)

Answer 7

1. normoblasts (erythrocyte progenitors)
2. erythropoietin
3. megakaryocytes
4. thrombopoetin.

Question 8

Megakaryocyte (2) becomes (1) in response to other factors.

Answer 8

2. cytoplasm and membrane

1. platelets

Question 9

Myeloid differentiation: (1) confers eosinophilic differentiation

Answer 9

1. IL-5

Question 10

Myeloid differentiation: (1) confers granulocytic differentiation

Answer 10

1. G-CSF

Question 11

Myeloid differentiation: (1) confers monocyte differentiation

Answer 11

1. M-CSF

Question 12

Erythropoiesis is perhaps the ultimate example of the inverse relationship between cell proliferation and differentiation since completely formed red blood cells lose their (1) so they can no longer divide or synthesize proteins.

Answer 12

1. nuclei and ribosomes

Question 13

Erythroid progenitors can basically either form (1) which are large collection of red cell progenitors or they can form (2) which are smaller populations

Answer 13

1. bursts

2. colonies

Question 14

During human embryologic development, blood formation begins initially in the (3) but then the (1) are the major sites for red cell production during the (2) trimester.

Answer 14

3. blood islands in extraembryonic tissues
4. liver and spleen
5. second

Question 15

When does the bone marrow become the major site of red cell development?

Answer 15

during the third trimester and after birth

Question 16

In certain disorders with poor erythropoesis there can be a reversion to (1) hematopoesis in adult life which can involve a number of organs but most commonly involves (2)

Answer 16

1. extramedullary (outside bone marrow)

2. liver or spleen

Question 17

Fetal red blood cells also express embryonal (1) and fetal hemoglobin (2) prior to the predominant production of adult hemoglobins (3) after birth and in adult life. This phenomenon is called (4)

Answer 17

1. HBepsilon and HAzeta
2. HBgamma
3. delta and beta
4. hemoglobin switching.

Question 18

embryonal hemoglobgin

Answer 18

HBepsilon and HAzeta

Question 19

fetal hemoglobin

Answer 19

HBgamma

Question 20

Adult hemoglobin

Answer 20

delta and beta

Question 21

In patients with thalassemia or sickle cell anemia, the persistence of (1) can improve oxygenation to tissues.

Answer 21

1. fetal gamma hemoglobin

Question 22

nucleated red cells

Answer 22

normoblasts (orthochromatic erythroblast)

Question 23

red cells with ribosomes for Hb synthesis but without nuclei

Answer 23

reticulocytes (polychromatic erythrocytes

Question 24

Stem cells attached by (1) junctions to
(2) lining the inner surface of
bone cavities

Answer 24

1. adherens

2. osteoblasts

Question 25

bursts vs. colonies

Answer 25

bursts - high proliferation rate; more primitive | colonies - lower proliferation rate, high differentiation stage; later lineage cels produce colonies

Question 26

Hematopoesis in children versus elderly

Answer 26

Occurs in bone marrow of: Children - long bones (tibia and femur) Elderly - central bones vertebrae and pelvis)

Question 27

Fetal hemoglobin is resistant to (1) which makes it easier to measure in the lab

Answer 27

1. alkali

Question 28

What factors shift the oxygen dissociation curve of hemoglobin?

Answer 28

An increase in CO2, acid, DPG, exercise and temperature make the curve go to the right. "CADET face right"

Question 29

Embryo vs. fetus;

Answer 29

Embryo--> fertilization to 8th week of gestation; | Fetus--> 8th week to birth;

Question 30

Embryo vs. fetus vs. adult; compare Hb types.

Answer 30

Embryo--> "Gower" hemoglobin consisting of EPSILON and A Zeta chain; Fetal--> fetal Hb consisting of alpha2 and GAMMA2 Adult Hb--> alpha 2 and BETA2 (predominantly) or alpha2 and DELTA2

Question 31

Benign vs. malignant tumor clonality

Answer 31

Benign: multi-clonal - Like inflammatory or benign lymphoproliferative type multi-clonal - Malignant: Expansion of a single clone -> mono-clonal

Question 32

Why is chemotherapy not more successful?

Answer 32

Targets highly proliferative cells such as malignant cell, but also kills of some hematopoietic stem cells; since the HSC dont divide as often, it leaves patients at risk for infection, etc.

Question 33

Bone marrow vs. blood vs. tissue

Answer 33

Primitive cells found in bone marrow; Blood--> only DIFFERENTIATED cells here; if you see primitive cells then may be lymphoma; Tissue--> mast cells, macrophages, plasma cell, etc

Question 34

Myeloid progenitor-->G-CSF; GM-CSF

Answer 34

G-CSF-->Basophil and neutrophil | GM-CSF--> nonspecific;

Question 35

Platelets are the cytoplasm and membrane of megakaryocytes; no 1). But, they do have 2)

Answer 35

1) NUCLEI | 2) mitochondria (since need E for E-depdent processes.

Question 36

Mature RBCs vs. platelets

Answer 36

BOTH have no nuclei; | Platelets have mitochondria; RBCs have NO mitochondria or any organelles;

Question 37

As erythrocytes mature, they 1)_____; 2)_____ 3)decrease in ___

Answer 37

1) lose nuclei; 2) lose organelles; 3) membrane, proteins, and cytoskeleton

Question 38

As erythrocytes mature, histologically, start off 1) but as lose nuclei and gain Hb get more 2)

Answer 38

1) blue | 2) RED

Question 39

First place where hematopoiesis occurs in fetus

Answer 39

yolk sac (early) then liver and spleen (second trimester) then bone marrow (third)

Question 40

Adult hematopoiesis

Answer 40

Vertebra and pelvis; followed by STERNUM

Question 41

B cell development--> 1) and 2) as early markers; first secrete Immunoglobulin 3) which then classs switch to 4)

Answer 41

1 and 2) CD34 and TDT 3) IgG 4) IgM and IgD

Question 42

B cell development--> antigen independent in ____ | antigen dependent in _____

Answer 42

1) bone marrow; | 2) peripheral lymphoid tissues