heam- blood cell physiology

Question 1

what is the origin and function of red cells

Answer 1

origin: myeloid stem cells in BM
Function: O2/ CO2 transportation

Question 2

what is the intravascular lifespan of red cells

Answer 2

lifespan: 120 days

Question 3

what physiological factors influence the production of red cells

Answer 3

Erythropoietin
this is produced by the juxtatubular interstitial cells in the KIDNEY (also a little in the liver) in response to HYPOXIA
can also be in response to anaemia

Question 4

what is the origin, function and intravascular lifespan of Neutrophils

Answer 4

origin: myeloid stem in BM -> myeloblast –> granuloocyte
Function: defense against infection (phagocytosis)
lifespan: 7-10 hours (before migration to tissues)

Question 5

what is the origin, function and intravascular lifespan of Eosinophils

Answer 5

origin: myeloid stem in BM -> myeloblast –> granuloocyte
Function: defense against PARASITIC infections
lifespan: (less than neutrophils) ie few hours ?

Question 6

what is the origin, function and intravascular lifespan of Basophils

Answer 6

origin: myeloid stem in BM -> myeloblast –> granuloocyte
Function: role in ALLERGIC responses
lifespan: hours to days

Question 7

what is the origin, function and intravascular lifespan of lymphocytes

Answer 7

origin: lymphoid stem cells–>lymphocytes
Function: respond to foreign bodies in body
lifespan: variable (years for memory)

Question 8

what is the origin, function and intravascular lifespan of platelets

Answer 8

origin: myeloid stem cells–>megakaryocytes–> platelets
Function: primary haemostasis
lifespan: 10 days

Question 9

what is meant by MCV plus show equation

Answer 9

MCV= total volume of RBC’s in a sample/ number of RBCs in sample in fL

Question 10

what is meant by MCH + equation

Answer 10

MCH= Hb in sample/ RBCs in sample in Pg

Question 11

what is the difference between a normal range and reference range

Answer 11

both show range in 95% of healthy individuals, but reference takes into account age, gender, ethnic origin, altitude etc…

Question 12

what is meant by MCHC + equation

Answer 12

MCHC= HB in sample/proportion of RBCs in the same samplehemostasisie MCHC=HB/HCT in g/L

Question 13

what is the origin, function and intravascular lifespan of Monocytes

Answer 13

origin: myeloid stem cells–> monocyte precursors
Function: migrate to tissue–> develop into macrophage and then phagocytosis of pathogens (and also store/release iron)
lifespan: several days

Question 14

what is meant by Left shift

Answer 14

increase in number of non-segmented neutrophils/neutrophil precursors (infection and inflammation)

Question 15

what is meant by Toxic granulation

Answer 15

heavy granulation of neutrophils (infection, inflammation and tissue necrosis, but also normal in pregnancy)

Question 16

what is meant by Hypersegmented neutrophil

Answer 16

increase in the number of lobes/segments per neutrophil (lack of vitamin B12 or folic acid, leading to 5+ segments)

Question 17

What is anisocytosis

Answer 17

variation in SIZE

Question 18

what is poikilocytosis

Answer 18

variation in SHAPE ( eg spherocytes, sickle cell, I.C.C, target cells etc…)

Question 19

what is hypochromia

Answer 19

larger central pallor (>1/3 of area is pale) eg target cells

Question 20

what is hyperchromia

Answer 20

smaller/no central pallor (seen in irregularly contracted cells and spherocytes)

Question 21

what is polychromia

Answer 21

blue tinge to cytoplasm = reticulocyte (young immature cell) (can be caused by damage to bone marrow eg by cancer.

Question 22

what is a rouleau

Answer 22

stacks of red cells (like coin stack) due to changes in plasma protein

Question 23

what are agglutinates

Answer 23

clumps (irregular stacks) of red cells due to antibodies (igM) on surface–> ^stickiness

Question 24

what are howell jolly bodies

Answer 24

nuclear remnant in cell (dark purple spot in cell) can be caused by lack of splenic function