Physiology of blood cells and haematological terminology

Question 1

Where do all types of blood cell originate?

Answer 1

Bone marrow

Question 2

What are blood cell types derived from?

Answer 2

Pluripotent haemopoietic stem cells

Question 3

What do pluripotent haemopoeitic stem cells give rise to?

Answer 3

Multipotent myeloid stem cells/precursor or lymphoid stem cells

Question 4

What can multipoint myeloid stem cells give rise to?

Answer 4

Granulocytes (monocytes)
Erythroid’s
Megakaryocytic
Proerythroblasts which give rise to erythroblasts and then erythrocytes

Question 5

What can lymphoid stem cells give rise to?

Answer 5

T cells
B cells
NK cells

Question 6

What is erythropoiesis?

Answer 6

Process of producing red blood cells

Question 7

What does erythropoiesis require?

Answer 7

Presence of erythropoietin

Question 8

Where is erythropoietin synthesised?

Answer 8

Mainly the kidney- juxtatubular interstitial cells (90%)

10% by hepatocyte and interstitial cells of liver

Question 9

What stimulates the synthesis of erythropoietin?

Answer 9

Hypoxia

Question 10

How long do erythrocytes survive in the blood stream?

Answer 10

120 days

Question 11

What are the functions of erythrocytes?

Answer 11

Oxygen and carbon dioxide transport

Question 12

What ultimately destroys erythrocytes?

Answer 12

Phagocytic cells of the spleen

Question 13

What is anisocytosis?

Answer 13

Red cells show more variation in size than normal

Question 14

What is poikilocytosis?

Answer 14

Red cells show more variation in shape than normal

Question 15

What does microcytic mean?

Answer 15

Red cells that are smaller than normal

Question 16

What does normocytic mean?

Answer 16

Red cells that are of a normal size

Question 17

What does macrocytic mean?

Answer 17

Red cells that are larger than normal

Question 18

What fraction of a normal red cells diameter is pale?

Answer 18

One third

Question 19

Why is a part of a red cell pale?

Answer 19

Due to the disc shape, centre has less haemoglobin

Question 20

What is hypochromia?

Answer 20

Larger area of central pallor than normal

Question 21

What does hypochromia result from?

Answer 21

Lower haemoglobin content and concentration and the cell is flatter

Question 22

What does hypochromia often occur with?

Answer 22

Microcytosis

Question 23

What is hyperchromia?

Answer 23

Cell lacks central pallor

Question 24

What does hyperchromia result from?

Answer 24

Cells being thicker than normal or abnormal shape

Question 25

What are spherocytes?

Answer 25

Cells that are approximately spherical with a regular outline but lack central pallor

Question 26

What causes spherocytosis?

Answer 26

Loss of cell membrane without loss of an equivalent amount of cytoplasm so cell is forced to round up

Question 27

What are irregularly contracted cells?

Answer 27

Irregular in outline, smaller than normal and lack central pallor

Question 28

What does irregularly contracted cells normally result from?

Answer 28

Oxidant damage to the cell membrane and haemoglobin

Question 29

What is polychromasia?

Answer 29

Increased blue tinge to the cytoplasm of a red cell

Question 30

What does polychromasia indicate?

Answer 30

The cell is young

Question 31

What is a common way to detect young cells?

Answer 31

A reticulocyte stain- exposes living red cells to new methylene blue which precipitates as a network or reticulum

Question 32

What are sickle cells?

Answer 32

Cells that are sickle or crescent shaped

Question 33

What causes sickle cells?

Answer 33

Polymerisation of haemoglobin S when it is present in a high concentration

Question 34

What are target cells?

Answer 34

Cells with an accumulation of haemoglobin in the centre of the area of central pallor (Look like a target)

Question 35

When do target cells occur?

Answer 35

Obstructive jaundice, liver disease, haemoglobinopathies and hyposplenism

Question 36

What are eliptocytes?

Answer 36

Cells that are elliptical in shape

Question 37

When do eliptocytes occur?

Answer 37

Hereditary eliptocytosis and iron deficiency

Question 38

What are rouleaux?

Answer 38

Stacks of red cells (pile of coins)

Question 39

What are rouleaux due to?

Answer 39

Alterations in plasma proteins

Question 40

What are agglutinates?

Answer 40

Irregular clumps of red cells

Question 41

What do agglutinates result from?

Answer 41

Antibody on the surface of the cells

Question 42

What is a Howell-Jolly body?

Answer 42

Nuclear remnant in a red cell

Question 43

What is the commonest cause of Howell-Jolly body?

Answer 43

Lack of splenic function

Question 44

What is the main function of neutrophils?

Answer 44

Defence against infection, it phagocytoses and then kills micro-organisms

Question 45

How long do neutrophil granulocytes survive in circulation before migrating to tissues?

Answer 45

7-10 hours

Question 46

What is the main function of eosinophils?

Answer 46

Defence against parasitic infection

Question 47

What is the function of basophils?

Answer 47

Allergic responses

Question 48

How long do monocytes spend in circulation?

Answer 48

Several days

Question 49

What is the function of monocytes?

Answer 49

When they migrate to tissues, they develop into macrophages and other specialised cells that have a phagocytic and scavenging function They also store and release iron

Question 50

How long do platelets survive in circulation?

Answer 50

10 days

Question 51

What is the role of platelets?

Answer 51

Primary haemostats- contribute phospholipid which promotes blood coagulation

Question 52

What is leucocytosis?

Answer 52

Too many white cells

Question 53

What is leucopenia?

Answer 53

Too few white cells

Question 54

What is neutrophilia?

Answer 54

Too many neutrophils

Question 55

What is neutropenia?

Answer 55

Too few neutrophils

Question 56

What is lymphocytosis?

Answer 56

Too many lymphocytes

Question 57

What is left shift?

Answer 57

Increase in non-segmented neutrophils or neutrophil precursors in the blood

Question 58

What is toxic granulation?

Answer 58

Heavy granulation of neutrophils

Question 59

What does toxic granulation result from?

Answer 59

Infection, inflammation and tissue necrosis

Question 60

What is neutrophil hypersegmentation?

Answer 60

Increase in average number of neutrophil lobes or segments

Question 61

What does neutrophil hypersegmentation result from?

Answer 61

Lack of vitamin B12 or folic acid