Erythropoiesis

Question 1

A stem cell has 2 main properties which are?

Answer 1

• It is capable of mitotic division and capacity for self renewal, which enables the cell to perpetuate itself.

• It is capable of cell division that results in cell differentiation. That is, it divides (into daughter cells)

Question 2

Progenitor cells are?

Answer 2

Cells committed to an hemopoietic lineage but have no microscopic or morphological identity

Question 3

Precursor cells are

Answer 3

cells committed to a given haemopoietic lineage and are morphologically identifiable

Question 4

the stem cell pools are usually ____& _________positive.

Answer 4

CD34-positive and stem cell factor-

Some progenitor cells may also be CD34-positive, but are usually not stem cell factor-positive.

Question 5

the first morphologically identifiable erythroid cell in the bone marrow is the ie the first precursor cell is ?

Answer 5

proerythroblast

Question 6

The red cell progenitors are ?

Answer 6

BFU-E and CFU-E.

Question 7

The biochemical identification of the progenitor cell is?

Answer 7

The appearance of ABO blood group antigen on the membrane if these cells in small quantities.

They also begin to express receptors for erythropoietin

Question 8

The most important morphological identity of a proerythroblast, like other red cell precursors, is?

The cytoplasm of the proerythroblast is completely _________ in colour. It is rich in DNA that is waiting to be translated to haemoglobin.

Answer 8

the coin circularity of the nucleus

Dark blue

Question 9

Traces of haemoglobin in proerythroblast can be detected by _____ test

Answer 9

Feulgen Stain

Question 10

Romanowski stains

Answer 10

This refers to dyes used in staining the protein component of cellular structures.

Question 11

1 proerythroblast gives rise to __ reticulocytes.

Answer 11

16

Question 12

Acids complex with _____

Basics bind with _____

Answer 12

Basic dyes
Acidic dyes

Question 13

Thus, erythroid maturation implies ______& _______

Answer 13

cytoplasmic haemoglobinization and pyknosis of the nucleus.

Question 14

Reticulocyte = ________ orthochromatic erythroblast

Answer 14

Anucleated

Question 15

The reticulocyte has remnants of

Answer 15

ER
Mitochondrial material
Rihosomal material
Nuclear materials

Question 16

The length of time between maturation of the polychromatic cell to reticulocyte in the bone marrow is approximately ______

Answer 16

5 days

In severe anaemic conditions, this length of time may be shortened—as is seen in sickle cell anaemia.

Question 17

In the spleen, reticulocytes take another _______ hours to become fully mature erythrocytes. This maturation of reticulocytes involves the removal in the spleen of fragments of nuclear material that hitherto were not fully enucleated in the bone marrow. It also involves the removal of leftover ribosomes.

Answer 17

48

Question 18

The nature erythrocyte leaves the spleen and circulates for ____ days

Answer 18

120

Question 19

Between proerythroblast and orthochromatic erythroblast are ____ divisions

Answer 19

4

Question 20

Write out erythropoiesis

Answer 20

Pluripotential stem cell
Myeloid committed stem cell
BFU- E
CFU-E
Proerythroblast
Basophilic erythroblast type 1
Type 2
Polychromatic E
Orthochromatic E
Reticulocyte
Erythrocyte

Question 21

Functions of erythrocyte are

Answer 21

Reversible transfer of oxygen
Buffer system
Detoxification

Question 22

__________ describes the inability of the cell’s nucleus to mature or replicate while cytoplasm is maturing and becoming more hemoglobinized

Answer 22

nuclear cytoplasmic asynchrony: Megaloblastic/ macrocytic anaemia

This leads to bigger cells but less than 16 divisions and very rich in hemoglobin

Question 23

In microcytic anaemia?

Answer 23

Nucleus is maturing and replicating but there is an impairment in hemoglobin synthesis.

The number of division increases but the cell size is greatly reduced and poorly in hemoglobin

Question 24

The inability of the spleen to remove the normal reticulocyte inclusion bodies may result in the formation of red cells that are pathological with respect to the inclusion bodies.
The pathological red cell inclusion bodies include:

Answer 24

Howell-Jolly bodies: nucleus
Heinz bodies: hemoglobin
Pappeinheimer bodies: mitochondria
Cabot ring inclusion bodies : mitosis strands

Question 25

In Howell-Jolly bodies

Answer 25

fragments of red blood cell nucleus or erythroblast nucleus that are not completely removed from the red cell

Question 26

Heinz bodies?

They are seen in?

Answer 26

are usually precipitates of haemoglobin, which form crystals in the red blood cell. They are usually seen in some forms of thalassaemias.

Question 27

Pappeinheimer bodies:
They are commonly seen in?

Answer 27

ion-laden mitochondria that are not removed by the spleen. They are commonly seen in sideroblastic anaemias.

Question 28

Cabot ring inclusion bodies

They are seen in ?

Answer 28

feature of abnormality of mitosis where the strands that pull the nuclear bodies apart during telophase fail to be removed or destroyed and are retained in the cytoplasm of mature red blood cell.

They are usually seen in severe megaloblastic anaemia.

Question 29

The shape of a normal red blood cell is called ______ , thus the reason why it is called a discocyte. The diameter of a normal erythrocyte is ____ and width _____

Answer 29

Binconcave

8μ, and its width is 3μ.

Question 30

There are a number of pathological red cell shapes that can be used to mirror disease states in the human body:

Answer 30

Spherocytes: rather than the red blood cell to be a discocyte, it may be a complete sphere (spherocyte). Spherocytes are diagnostic of hereditary spherocytosis. They may also be found in immune haemolytic anaemia (microspherocytes).
• Drepanocytes (sickle cell): Mirrors the presence of sickle-cell disease.
• Dacrocytes: these are pointed erythroid cells with long horns that are seen in stresses bone marrow (bone marrow that has been infiltrated by fibrous tissue as in myeloscelrosis or myelofibrosis).
• Echinocytes: they may be spherocyrtes or discocytes. They have bumps or projections on the surface of their membrane that are equally spaced among one another. They are found in individuals with uraemia or chronic renal disease.
• Acanthocytes: they are like echinocytes, but have fewer and longer membrane projections. They are seen in malabsorption syndromes, liver cirrhosis, alcohol liver disease, β-lipoproteinaemia.
• Stomatocytes: they are seen in hereditary stomatocytosis, chronic renal disease, and malabsorption states.

Codocytes: They are seen in chronic renal diseases, thalassaemia, iron- deficiency anaemia.
• Schistocytes: are also known as fragmented cells. They are often seen in immune vasculitides, in disseminated intravascular coagulation, and in other forms of red blood cell fragmentation syndromes, such as thrombolytic thrombocytopenic purpura and haemolytic urinary syndrome.

Question 31

Life span of rbc

Answer 31

120 days

Question 32

Depranocyte

Answer 32

Sickles cells

Question 33

Dacrocyte

Answer 33

Tear drop shaped
A type of poikilocyte
Seen in myelofibrosis

Question 34

Blood is _____ times more viscous than water

Answer 34

4 to 5