Physiology of blood cells

Question 1

what do pluripotent haematopoietic stem cells give rise to?

Answer 1

myeloid stem cells

lymphoid stem cells

Question 2

what are the key features of stem cells?

Answer 2

self renewal

mature progeny production

Question 3

what do myeloid stem cells become?

Answer 3

granulocytes
monocytes
erythroid
megakaryocyte

Question 4

what do lymphoid stem cells become?

Answer 4

T cell
B cell
Natural killer cell

Question 5

what are the stages of transformation of multipoint myeloid stem cell to erythrocyte?

Answer 5

myeloid stem cell
proerythroblast
erythroblast
erythrocyte

Question 6

where is erythropoietin produced, and in response to what?

Answer 6

mainly in the kidneys (90%)
in hepatocytes and interstitial cells of liver (10%)
in response to hypoxia

Question 7

life span of erythrocytes

Answer 7

120 days

Question 8

where does removal of erythrocytes occur?

Answer 8

in the spleen

Question 9

Through which cell does transformation of multipoint myeloid stem cell to granulocytes and monocytes take place?

Answer 9

via myeloblast

requires cytokines and interleukins

Question 10

life span of neutrophil

Answer 10

7-10 hours in circulation before migrating into tissues

Question 11

function of neutrophils

Answer 11

against infection

Question 12

lifespan and function of eosinophils

Answer 12

less time spent in circulation than neutrophils

defence against parasitic infection

Question 13

function of basophils

Answer 13

in allergic response

Question 14

life span of monocyte

Answer 14

several days in circulation

Question 15

function of monocytes

Answer 15

become macrophages in tissues
phagocytose
store and release iron

Question 16

transformation of multipoint haemp. stem cell to platelet

Answer 16

via megakaryocyte

Question 17

life span of platelet in circulation

Answer 17

10 days

Question 18

function of platelet

Answer 18

primary haemostasis by

contributing to phospholipid in blood coagulation

Question 19

circulation of lymphocytes

Answer 19

recirculate into lymph nodes and lymphoid tissues and back into the blood stream

lifespan intervascularly varies a lot

Question 20

what is the variation in size of cells

Answer 20

anisocytosis

Question 21

what is the variation in shape of cells

Answer 21

poikilocytosis

Question 22

what has happened if cells are smaller than normal?

Answer 22

microcytosis

Question 23

what has happened if cells are larger than normal?

Answer 23

macrocytosis

Question 24

shapes of macrocytes

Answer 24

round
oval
polychromatic

Question 25

what are the 3 categories of anaemia?

Answer 25

microcytic- smaller than normal red cells/anaemia with small RBC normocytic- red cells normal/anaemia with normal RBC macrocytic- larger than normal red cells/anaemia with large RBC

Question 26

what causes the large central pallor in RBCs

Answer 26

this region has less Hb and therefore the cell is flatter

Question 27

what area of the RBC has pallor

Answer 27

third of the diameter

Question 28

what is hypochromia? | - pallor

Answer 28

increased central pallor goes hand-in-hand with microcytosis

Question 29

what are cells like in hyperchromia?

Answer 29

cells are thicker than normal abnormal shape lack central pallor

Question 30

what are the two types of cells in hyperchromia?

Answer 30

1) spherocytes | 2) irregular contracted cells

Question 31

what causes spherocytes to be formed in hyperchromia?

Answer 31

loss of cell membrane without the equivalent loss of cytoplasm forcing the cell to round up

Question 32

2 disease with characteristic spherocytes?

Answer 32

hereditary spherocytosis autoimmune haemloytic anaemia

Question 33

describe irregularly contracted cells

Answer 33

irregular outline smaller than normal lack of central pallor

Question 34

what causes irregularly contracted cells to be formed in hyperchromia?

Answer 34

oxidant damage to cell membrane and Hb seen in hyposplenism and haemolysis

Question 35

what does polychromasia describe?

Answer 35

increased blue tinge to cytoplasm of RBC

Question 36

what does a blue tinge of the cytoplasm of RBC indicate

Answer 36

the RBC is young and often larger in polychromasia

Question 37

how can you detect young cells in a stain?

Answer 37

blue tinge reticulocytes stain- using new methylene blue to do a reticulocyte count the stain in more reliable in diagnosing polychromasia than using the blue tinge

Question 38

what would you expect the reticulocyte count to be in a normal person?

Answer 38

1-2% of circulation cells should be young reticulocytes

Question 39

what are the poikilocytes

Answer 39

``` spherocytes irregularly contracted cells sickle cells target cells elliptocytes fragments ```

Question 40

what causes the formation of target cells?

Answer 40

accumulation of Hb in the centre of the central pallor area

Question 41

in which diseases do target cells occur

Answer 41

obstructive jaundice liver disease haemoglobinopathies hyposplenism (lack of spleen function, due to removal)

Question 42

which diseases do elliptocytes occur?

Answer 42

hereditary elliptocytosis | iron deficiency

Question 43

what causes sickle cells to form?

Answer 43

polymerisation of Hb S chains when present at a high enough concentration

Question 44

what does the presence of fragments indicate?

Answer 44

that a RBC has fragmented due to abnormal stress to the cell or if the cell has been intrinsically abnormal in the first place

Question 45

what are the 2 ways poikilocytes clump together?

Answer 45

rouleaux- neat stack of RBCs | agglutinates- irregular clumps of RBCs

Question 46

what causes a rouleaux to form?

Answer 46

alterations in plasma proteins

Question 47

what causes agglutinates to form?

Answer 47

antibodies attaching to RBC antigens

Question 48

what can a lack of splenic function also cause to appear commonly?

Answer 48

a Howell-Jolly Body | - nuclear remnant of RBC

Question 49

"too many"

Answer 49

- cytosis and -philia | e. g. leucocytosis, neutrophilic , eosinophilia, lymphocytosis

Question 50

"too few"

Answer 50

- penia | e. g. leucopenia, neutropenia

Question 51

what describes an increase in non-segmented neutrophils?

Answer 51

left shift - presence of neutrophil precursors in the blood - band form [the transformation goes backwards, to the left]

Question 52

what is toxic granulation?

Answer 52

heavy granulation of neutrophils as a result of infection, inflammation and tissue necrosis also normal in pregnancy

Question 53

what do you see in right shift?

Answer 53

hypersegemented neutrophils increase in average number of neutrophil lobes caused by lack of vitamin B12 or folic acid (e.g. in megaloblastic anaemia where DNA synthesis has been inhibited)