Haemopoiesis

Question 1

are there more RBCs or WBC in circulation?

Answer 1

there are more than 500 time more RBCs than WBCs in circulation

Question 2

all peripheral blood cells are derived from … ?

Answer 2

a pluripotent stem cell

Question 3

progenitor cells can divide to produce what type of cells?

Answer 3

• Erythrocytes
• megakaryoctes
• granulocytes
• lymphocytes
• monocytes

Question 4

What are platelets derived from?

Answer 4

They break off of megakaryocytes

Question 5

What are the three main types of granulocytes?

Answer 5

neutrophils

eosinophils

basophils

Question 6

What are the two main types of agranulocytes?

Answer 6

lymphocytes and monocytes

Question 7

What are neutrophils?

Answer 7

They are the first line of defence against bacterial infection - they are phagocytes

Question 8

What are eosinophils? What is their function ?

Answer 8

they combat viral and parasitic infections - play a role in allergic response and asthma pathogenesis

Question 9

What are basophils? What is their function?

Answer 9

they are the least numerous WBC and they contain large cytoplasmic granules - they synthesize and store histamine and heparin

Question 10

what are lymphocytes? What is their function??

Answer 10

they are a key element in acquired immunity including B and T cells - they play a hge role in cancer fighting etc.

Question 11

What are monocytes?

Answer 11

they are the early form of macrophages - they engulf and kill acteria/ remove aged RBCs

Question 12

What are the required growth factors for haemopoiesis?

Answer 12

• erythropoietin
• colony stimulating factors
• interleukins
• thrombopoietin - accelerate producion of platelets

Question 13

Where are red blood cells made in the fetus vs. adult?

Answer 13

fetus: yolk sac, liver, spleen, red bone marrow

adult : red bone marrow, extramedullary

Question 14

What are the stages of erythropoiesis?

Answer 14

1. proerythroblast = the first cell that you can identify as a RBC
2. basophilic = early erythroblast
3. polychromatic erythroblast
4. orthochromatic erythroblast
5. reticulocyte = released into circulation
6. Mature RBC

Question 15

How manny mature RBCs does one proerythroblast give rise to?

Answer 15

typically, one proerythroblast gives rise to about 16 mature RBCs

Question 16

how long does erythropoiesis take?

Answer 16

it takes about a week to form a mature RBC

Question 17

What are the clinical signs of anaemia?

Answer 17

Pallor

Koilonychia

Angular Stomatitis

Glossitis

Question 18

What is hypochromic-microcytic anaemia?

Answer 18

less than normal color and smaller cells - typically with iron deficiency - body is unable to meet the demands of blood

Question 19

what is normochromic macrocytic anaemia?

Answer 19

due to folate deificiency or B12 deficiency, one has average haemoglobin levels but too large of cells

Question 20

what is polychromatophilic macrocytic anaemia?

Answer 20

varied levels of Hg and cells are too large -

result of haemolysis

Question 21

What is the most common form of anaemia?

Answer 21

iron deficiency anaemia = hypochromic microcytic anaemia

*hypochromic b/c not enough Hb due to iron deficiency*

Question 22

what is the most common cuase of iron deficient anaemia (hypochromic microcytic anaemia)

Answer 22

acute or chronic blood loss -

due to trauma or post partum bleeding

Question 23

what is the cause of pernicious anaemia?

Answer 23

pernicious anaemia is specifically caused by malabsorption of vitamin B12 due to lack of intrinsic factor - so no matter how much they take they cannot absorb it

this results in macrocytic anaemia

Question 24

What are haemolytic anaemias

Answer 24

they are a reduced life span of erythrocytes - cause by a wide range of genetic or aquired disorders like sick cell anaemia, or immune incompatibility

Question 25

What is polycythaemia?

Answer 25

too many RBCs- increase in Hb, RBC, PCV above reference level - occurs in hypoxic conditions at high altitudes - why michael phelps trains in a hypoxic condition