Hematopiosis

Question 1

Primitive & definitive haemopoiesis occur where?

Answer 1

embryonic yolk sac

definitive haemopoiesis’ derives from a population
of stem cells first observed on the aorta-gonads-mesonephros
(AGM) region of the developing embryo

Question 2

From 6 weeks until 6–7 months of fetal life, the ______ are the major haemopoietic organs and continue to
produce blood cells until about 2 weeks after birth & ______ also contribute

Answer 2

Liver & spleen
Placenta

Question 3

The bone marrow becomes the most important afte

Answer 3

6-7 months

Question 4

The developing cells are situated outside the bone marrow sinuses; mature
cells are released into the sinus spaces, the marrow microcirculation and so into the general circulation

Question 5

What’s extramedullary haemopoiesis’

Answer 5

Production of red blood cells by the spleen and liver due to disease conditions

Question 6

Which of an adult skeleton is capable of hemapoasis

Answer 6

Vertebrae, ribs, sternum, skull, sacrum and
pelvis, proximal ends of femur

Question 7

Morphologically, HSCs have
the appearance of a

The are also heterogeneous

Answer 7

small or medium-sized lymphocyte

Question 8

List the bone marrow stromal cells and they secrete ____ to form ECM

Answer 8

Messenchymal stem cells, fibroblast, macrophages, adipocyte, endothelial cells and osteoblast

Glycoprotein, collagen, glycoaminoglycan,

Question 9

Messenchymal stem cells Together with _____ or &_______ cells, they form niches and provide some of the growth factors, adhesion molecules and cytokines which support stem cells, maintaining
their viability and reproduction.

Answer 9

osteoblasts or endothelial

Question 10

What’s mobilization and homing of stem cells
Its enhanced by? (M)

Answer 10

Mobilization is the process by which stems cells exit the bone marrow and the cells cross the blood vessel Emdothelium and is enhanced by granulocyte colony stimulating factor.

While homing is the reverse amd depends on Chemokine gradient

Question 11

Question: What happens during stem cell division?

Answer 11

Answer: In stem cell division, one cell replaces the stem cell (self-renewal), while the other commits to differentiation.

Question 12

What factors influence which cell lineage a progenitor cell follows?

Answer 12

Answer: The cell lineage selection depends on both chance and external signals received by progenitor cells.

Question 13

Which transcription factors regulate stem cell survival during hematopoiesis?

Answer 13

Answer: Transcription factors such as SCL, GATA2, and NOTCH1 play a role in stem cell survival.

Question 14

Which transcription factors commit cells to the myeloid lineage?

Answer 14

Answer: PU.1 and the CEBP family of transcription factors are involved in myeloid lineage commitment.

Question 15

What roles do GATA2, GATA1, and FOG1 play in hematopoiesis?

Answer 15

Answer: GATA2 initiates the process, while GATA1 and FOG1 have essential roles in erythropoietic and megakaryocytic differentiation.

Question 16

What proteins do transcription factors induce synthesis of?

Answer 16

Answer: Transcription factors induce synthesis of proteins specific to a cell lineage. For example, erythroid-specific genes have binding motifs for GATA1

Question 17

Question: What is the significance of binding motifs for transcription factors?

Answer 17

Answer: Binding motifs determine which genes are activated, leading to lineage-specific protein synthesis

Question 18

How do early committed progenitors express transcription factors?

Answer 18

Answer: Early committed progenitors express low levels of transcription factors that may commit them to discrete cell lineages.

Question 19

What are the regulators of hemopeisis

Answer 19

Transcription factor
Cell lineage selection

Question 20

How do growth factors act?

Answer 20

Cell to cell contact
Circulate in plasma
Or ecm

Question 21

The growth factors may cause cell proliferation,
but can also stimulate differentiation and maturation, prevent
apoptosis and affect the function of mature cells

Question 22

Stromal cells are the major source of
growth factors except for _____&, 90% of which is synthesized
in the kidney, and , made largely in
the liver.

Answer 22

EPO erythropiothin
thrombopoietin (TPO)

Question 23

Which growth factors act locally on pluripotential stem cells and myeloid/lymphoid progenitors?

Answer 23

Answer: SCF, TPO, and FLT3 ligand have local effects on these cell populations.

Question 24

What is the widespread activity of Interleukin-3 (IL-3)?

Answer 24

Answer: IL-3 has activity on both lymphoid/myeloid and megakaryocyte/erythroid progenitors.

Question 25

Which growth factors enhance neutrophil and macrophage/monocyte production?

Answer 25

Answer: Granulocyte–macrophage colony-stimulating factor (GM-CSF), G-CSF, and macrophage colony-stimulating factor (M-CSF) play this role.

Question 26

What does IL-5 specifically enhance in terms of blood cell production?

Answer 26

Answer: IL-5 boosts eosinophil production.

Question 27

Which growth factor influences mast cell development?

Answer 27

Answer: KIT is involved in mast cell development.

Question 28

How do lineage-specific growth factors interact with other factors during early hematopoiesis?

Answer 28

Answer: These lineage-specific growth factors enhance the effects of SCF, FLT3-L, and IL-3 on the survival and differentiation of early hematopoietic cells.

Question 29

What's the life span of rbc and plately

Answer 29

They have a 4-month lifespan, whereas the smallest cells, platelets involved in haemostasis, circulate for only 10 days

Question 30

Erythropoietin stimulates erythropoiesis by increasing the number of progenitor cells committed to erythropoiesis which is?

Answer 30

CFU Erythroid ---+ pronormoblast

Question 31

What are hypoxia-inducible factors (HIFs), and how do they relate to EPO production?

Answer 31

Answer: HIFs are proteins that stimulate EPO production during hypoxia. They also play a role in new vessel formation and transferrin receptor synthesis.

Question 32

Which transcription factor initiates erythroid differentiation from pluripotential stem cells?

Answer 32

Answer: The transcription factor GATA2 is involved in initiating erythroid differentiation.

Question 33

Which transcription factors are activated by EPO receptor stimulation?

Answer 33

Answer: GATA1 and FOG1 are activated by EPO receptor stimulation and enhance expression of erythroid-specific genes.

Question 34

What is the role of GATA1 and FOG1 in erythropoiesis?

Answer 34

Answer: They enhance expression of erythroid-specific genes, anti-apoptotic genes, and the transferrin receptor (CD71).

Question 35

Which cells have erythropoietin receptors? Answer: Late BFUE and CFUE (erythroid progenitors) have erythropoietin receptors.

Question 36

What can plasma EPO levels indicate in clinical diagnosis?

Answer 36

Answer: High EPO levels are seen in anemia, except in cases of renal failure or tumor-secreted EPO. Low levels occur in severe renal disease or polycythemia vera.

Question 37

What are the glucose metabolic pathway that occur in the RB cell?

Answer 37

Embden–Meyerhof Pathway Hexose Monophosphate (Pentose Phosphate) Shunt

Question 38

What's Embden–Meyerhof Pathway What's is special functions

Answer 38

This pathway is a series of biochemical reactions where glucose is broken down to produce energy for red blood cells (RBCs) Glucose enters the RBC from the plasma and is metabolized to lactate. This pathway also generates NADH, which is essential for converting methemoglobin (a non-functional form of hemoglobin with ferric iron) back to functional hemoglobin with ferrous iron. About 3% of hemoglobin oxidizes daily, needing this repair process The Luebering–Rapoport shunt, a side branch of this pathway, produces 2,3-DPG, which helps regulate how tightly hemoglobin holds onto oxygen.

Question 39

What's Hexose Monophosphate (Pentose Phosphate) Shunt

Answer 39

This pathway handles about 10% of glucose breakdown in RBCs, focusing on protection against oxidative damage. Process: Glucose-6-phosphate is converted through several steps to ribulose-5-phosphate. It produces NADPH, which works with glutathione to protect cell structures, including hemoglobin and the cell membrane, from oxidative damage.

Question 40

What is the primary pathway involved in red cell metabolism?

Answer 40

Answer: The Embden–Meyerhof pathway (glycolysis) metabolizes glucose to lactate, generating ATP for energy.

Question 41

What is the function of the Luebering–Rapoport shunt in the Embden–Meyerhof pathway?

Answer 41

Answer: The shunt generates 2,3-DPG, which plays a crucial role in regulating hemoglobin’s oxygen affinity.

Question 42

What percentage of glycolysis occurs through the hexose monophosphate (pentose phosphate) shunt?

Answer 42

Answer: Approximately 10% of glycolysis occurs through this oxidative pathway.

Question 43

What is the end product of the hexose monophosphate shunt?

Answer 43

Answer: The end products are NADPH and ribulose-5-phosphate

Question 44

What components make up the red cell membrane?

Answer 44

Answer: The red cell membrane comprises a lipid bilayer, integral membrane proteins, and a membrane skeleton.

Question 45

What percentage of the red cell membrane is protein?

Answer 45

Answer: Approximately 50% of the membrane is protein.

Question 46

Where do carbohydrates occur in the red cell membrane? What are the two main types of proteins in the red cell membrane?

Answer 46

Answer: Carbohydrates occur only on the external surface of the membrane Answer: The two main types of proteins are peripheral and integral proteins.

Question 47

Which protein is the most abundant in the membrane skeleton?

Answer 47

Answer: Spectrin is the most abundant protein.

Question 48

What are the two chains that make up spectrin?

Answer 48

Answer: Spectrin consists of two chains: α and β.

Question 49

What's Methaemoglobinaemia

Answer 49

This is a clinical state in which circulating haemoglobin is present with iron in the oxidized (Fe3+) instead of the usual Fe2+ state. It may arise because of a hereditary deficiency of methaemoglobin reductase or inheritance of a structurally abnormal haemoglobin (Hb M).

Question 50

What's the normal values for hemoglobin?

Answer 50

Males 135.0–175.0 Females 115.0–155.0 Haemoglobin (g/L)

Question 51

After puberty what hemoglobin values represent anemia? The lower limit for infants is?

Answer 51

110g/l 140g/L

Question 52

After acute major blood loss, anaemia is not immediately apparent because the total blood volume is reduced. It takes up to a day for the plasma volume to be replaced and so for the degree of anaemia to become apparent (see p. 385). Regeneration of red cells and haemoglobin mass takes substantially longer. The initial clinical features of major blood loss are therefore a result of reduction in blood volume rather than of anaemia.

Question 53

Symptoms of anemia

Answer 53

Rerina hemorrhage Lethargy Weakness Headache