Chapter 33

Question 1

What are the functions of RBC?

Answer 1

As it contains haemoglobin, it acts as acid buffer and also transport of oxygen and carbon dioxide

It also contains carbonic anhydrase enzyme

Question 2

What is the amount of RBC in men and women?

Answer 2

In men, it is 5.2 million
In women, it is 4.7 million

Question 3

What is the average volume of RBC in the blood?

Answer 3

RBC covers 90 to 95 mm³ of blood

Question 4

What is the shape and size of RBC?

Answer 4

RBC are biconcave cells with 1 µm thickness in the centre and 2.5 µm on the periphery with 7.8 µm diameter

Question 5

What is the advantage of RBC of having extra cell membrane?

Answer 5

RBC have extra cell membrane, then the content in it, so that it can squeeze through the blood capillaries easily

Question 6

In different phases of life, where are the RBC produced?

Answer 6

During fetal life, first in the York sac, then in the second trimester in the liver spleen and lymph nodes, and after birth, it is produced in the bone marrow

Question 7

In an adult, where are the RBC produced?

Answer 7

Only in the membranous bones

Question 8

All type of blood cells are formed from which cell ?

Answer 8

Pluripotential stem cells

Question 9

What are committed stem cells?

Answer 9

Pluripotential stem cells that are committed to a single cell line

Question 10

What is colony forming unit - erythrocytes?

Answer 10

They committed stem cells that are committed to form erythrocytes in the future

Question 11

What are growth inducers?

Answer 11

The factors that induce growth and reproduction of the virtually all types of cells

For example IL-3

Question 12

What are differentiation inducers?

Answer 12

The factors that induce the differentiation of a committed cell to one or more step towards the final adult cell

Question 13

Which factors influence the production of growth and differentiation factors?

Answer 13

The factors outside the bone marrow affect its production

Question 14

What are the stages of erythropoiesis?

Answer 14

Proerythroblast
Basophilic Erythro blast
Polychromatophilic Erythro blast
Orthochromatic erythroblast
Reticulocyte
Erythrocyte

Question 15

What regulates the erythropoiesis?

Answer 15

The production of erythropoietin

Question 16

In which cases the need for Erythropoietin production arises?

Answer 16

Anaemia, high altitude, diseases like cardiac failure and lung disease and in the destruction of bone marrow

Question 17

What is erythropoietin?

Answer 17

It is a hormone and glycoprotein with a molecular weight of 34,000

Question 18

Where is the erythropoietin formed?

Answer 18

90% of it is formed in the kidney by the fibroblast like interstitial cells of the tubules

10% is formed by the liver and other cells

Question 19

What is the process of formation erythropoietin?

Answer 19

Renal hypoxia occurs, then hypoxia inducible factor-1 is stimulated which is a transcription factor that binds to hypoxia response element in the erythropoietin gene and causes the formation of mRNA

Question 20

What are the factors required for the maturation of RBC?

Answer 20

Vitamin B12 and folic acid

Question 21

What happens in the deficiency of vitamin B12 and folic acid?

Answer 21

As both of these are required for the maturation of nuclei by the formation of thymidine triphosphate
Deficiency result in the failure of nuclear maturation due to which the lifespan of RBC decreases, and they have flimsy membranes so form macrocytes

Question 22

In which case, vitamin B12 absorption decreases?

Answer 22

In the case of atrophic gastric mucosa
As it results in the deficiency of intrinsic factor, which is responsible for the absorption of vitamin B12 in the intestine
It causes pernicious anaemia

Question 23

In which case folic acid deficiency occurs?

Answer 23

In the small intestinal disease called sprue
There is deficiency of folic acid, as it doesn’t absorb properly in the intestine