physiology of blood cells and terminology

Question 1

multipotent haematopeotic stem cells, what they form

Answer 1

give rise to lymphoid AND myeloid stem cells myeloid form granulocytes/monocytes, RBC and megakaryocytes lymphoid forms T, B and NK cells

Question 2

characteristics of stem cells

Answer 2

can form mature cells OR self renew ie form more stemc cells

Question 3

pathway of red blood cells- erythropoeisis

Answer 3

myelid= proerythroblast= erythronblasts= RBC in each case they divide to form new cells- erythroblasts squeeze cytoplasm into sinusoids, leaving nucleus behind which is broken down by macrophage

Question 4

importance of erythropoetin

Answer 4

needed for erythropoeisis- kidney produces more when little oxygen present/ anaemia, increasing bone marrow activity= more RBC

Question 5

production of erythropoeitin

Answer 5

90% in kidney by juxtatubular interstitial cells, 10% by liver by hepatocytes and interstitial cells erythropoeitin goes into capillary, then bone marow

Question 6

red blood cells duration, function and breakdown

Answer 6

survives 120 days O2 and some CO2 transport (although most CO2 in plasma) destroyed in spleen

Question 7

production of white cells +what it depends on

Answer 7

starts with myeloblasts which divide into 2- eventually cell division stops, and nucleus changes shape and divides into lobules granulocytes and monocytes are produced, depending on the cytokines (G-CSF= granulocyte colony stimulating factor), lso M-CSF

Question 8

how to see if there are large number of reticulocytes in blood

Answer 8

either a reticulocyte stain, or look at red blood cells which are slightly bigger and are slightly blue (have more ribosomes- called polychromatic)

Question 9

DIAGRAM neutrophil- lifespan, what it does and how it gets to tissue

Answer 9

this granuloocyte has a shorter lifespan (10 hrs) in blood, and then goes to tissue, where it phagocytoses MARGINATED neutrophils are those that adhere to endothelium, then go through via diapedesis, then migrate via chemotaxis into tissue

Question 10

eonisophil DIAGRAM

Answer 10

myeloblasts can also form this granulocyte - shorter lifespan thart neutrophils, and fights parasites by releasing granules

Question 11

basophils DIAGRAM

Answer 11

also granulocyte formed by myeloblasts- needed for allergic responses

Question 12

monocytes DIAGRAM

Answer 12

monocytes are larger than granulocytes with a lobulated nucleus, and have a much longer lifespan (10 days)- - form macrophages in tissue: can store iron when breaking down bare nuclei from erythropoeisis synthesis

Question 13

platelets

Answer 13

megakaryocytes are precursor- these are very large cells which fragment to form platelets platelets survive 10 days

Question 14

lymphocytes lifespan

Answer 14

lifespan variable

Question 15

define anisocytosis DIAGRAM

Answer 15

RBC show more variation in size than normal

Question 16

define poikilocytosis DIAGRAM

Answer 16

RBC show more variation in SHAPE than normal

Question 17

define microcytosis (thus microcyte)- comparison to lymphocyte

Answer 17

RBC smaller than normal ie microcytes RBC should be same size as lymphocyte nucleus normally- these are normocytic

Question 18

define macrocytosis thus macrocyte

Answer 18

RBC larger than normal ie macrocytes

Question 19

types of macrocytes

Answer 19

round, oval and polychromatic oval can indicate a vitamin B12 deficiency, polychromatic can suggest a haemmorhage or vitamin deficiency as well

Question 20

DIAGRAM RBC on inside and outside

Answer 20

normally red cells have a third of diameter that is pale (less haemoglobin) on inside, due to its disc shape this area known as central pallor

Question 21

hypochromia DIAGRAM

Answer 21

cells have larger central pallor than normal- due to lower haemoglobin content and flatter cell often goes with microcytosis due to same underlying causes eg iron deficiency

Question 22

hyperchromia and causes

Answer 22

cells have less central pallor than normal main 2 causes are spherocytes (abnormal shape like sphere on the right) and irregularly contracted cells (haemoglobin unevenly distributed and cell is small and dense)

Question 23

spherocytes cause

Answer 23

due to loss of cell membrane without loss of cytoplasm, so cell rounds up to enclose it occurs in hereditary spherocytosis

Question 24

irregular contracted cells

Answer 24

due to oxidant damage to cell membrane and haemoglobin, causing clumbing

Question 25

polychramasia and significance with limitation

Answer 25

increased blueness in cytoplasm of red cell- shows lots of ribosomes ie red cell is young important as need to do a reticulocyte stain- uses methylene blue: polychramasia alone not reliable

Question 26

types of poikilocytes

Answer 26

spherocytes, irregularly contracted cells, sickle cells, target cells (like a target with small spot of haemoglobin in middle), ellipocytes (like oval/ tear drop) and fragments (small bits of red cells)

Question 27

target cells- what it is and causes

Answer 27

haemoglobin accumulates in central pallor often occurs in liver disease and obstructive jaundice

Question 28

elliptocytes - when it occurs DIAGRAM

Answer 28

occurs in hereditary elliptocytosis (top) and iron deficiency (bottom- large central pallor)

Question 29

sickle cells cause

Answer 29

due to polymerisation of haemoglobin S

Question 30

rouleaux DIAGRAM

Answer 30

stacks of red cells like a pile of coins, due to changes in plasma proteins eg immunoglobulins

Question 31

agglutinates

Answer 31

irregular clumps rather than stack of coins, due to antibodies on surface of cells

Question 32

howell-jolly body DIAGRAM

Answer 32

remnant of a nucleus, due to lack of splenic function ie less breakdown

Question 33

define leucocytosis, leucopenia, neutrophila, neutropenia, lymphocytosis and eonisophila

Answer 33

too many WBC, too few, too many neutrophils, too few, too many lymphocytes, too many eonisophils

Question 34

define thrombocytosis, thrombocytopenia, erythrocytosis, reticulocytosis, lymphopenia

Answer 34

too many platelets, too few, increased number of RBC, increased no. of young cells, not enough lymphocytes

Question 35

atypical lymphocytes and when it occurs

Answer 35

abnormal- often occurs in infectious mononucleosis

Question 36

left shift DIAGRAM

Answer 36

increase in non-segemented (nucleus looks like a band, hasn’t separated) neutrophils ie more neutrophils, as production of neutrophils has shifted left

Question 37

toxic granulation DIAGRAM

Answer 37

too much granulation of neutrophils, often due to infection

Question 38

right shift DIAGRAM

Answer 38

where neutrophil is hypersegmented, so increase in number of nucleus lobes due to B12/folic acid deficiency