heam- blood cell physiology Flashcards
(24 cards)
what is the origin and function of red cells
origin: myeloid stem cells in BM
Function: O2/ CO2 transportation
what is the intravascular lifespan of red cells
lifespan: 120 days
what physiological factors influence the production of red cells
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
what is the origin, function and intravascular lifespan of Neutrophils
origin: myeloid stem in BM -> myeloblast –> granuloocyte
Function: defense against infection (phagocytosis)
lifespan: 7-10 hours (before migration to tissues)
what is the origin, function and intravascular lifespan of Eosinophils
origin: myeloid stem in BM -> myeloblast –> granuloocyte
Function: defense against PARASITIC infections
lifespan: (less than neutrophils) ie few hours ?
what is the origin, function and intravascular lifespan of Basophils
origin: myeloid stem in BM -> myeloblast –> granuloocyte
Function: role in ALLERGIC responses
lifespan: hours to days
what is the origin, function and intravascular lifespan of lymphocytes
origin: lymphoid stem cells–>lymphocytes
Function: respond to foreign bodies in body
lifespan: variable (years for memory)
what is the origin, function and intravascular lifespan of platelets
origin: myeloid stem cells–>megakaryocytes–> platelets
Function: primary haemostasis
lifespan: 10 days
what is meant by MCV plus show equation
MCV= total volume of RBC’s in a sample/ number of RBCs in sample in fL
what is meant by MCH + equation
MCH= Hb in sample/ RBCs in sample in Pg
what is the difference between a normal range and reference range
both show range in 95% of healthy individuals, but reference takes into account age, gender, ethnic origin, altitude etc…
what is meant by MCHC + equation
MCHC= HB in sample/proportion of RBCs in the same samplehemostasisie MCHC=HB/HCT in g/L
what is the origin, function and intravascular lifespan of Monocytes
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
what is meant by Left shift
increase in number of non-segmented neutrophils/neutrophil precursors (infection and inflammation)
what is meant by Toxic granulation
heavy granulation of neutrophils (infection, inflammation and tissue necrosis, but also normal in pregnancy)
what is meant by Hypersegmented neutrophil
increase in the number of lobes/segments per neutrophil (lack of vitamin B12 or folic acid, leading to 5+ segments)
What is anisocytosis
variation in SIZE
what is poikilocytosis
variation in SHAPE ( eg spherocytes, sickle cell, I.C.C, target cells etc…)
what is hypochromia
larger central pallor (>1/3 of area is pale) eg target cells
what is hyperchromia
smaller/no central pallor (seen in irregularly contracted cells and spherocytes)
what is polychromia
blue tinge to cytoplasm = reticulocyte (young immature cell) (can be caused by damage to bone marrow eg by cancer.
what is a rouleau
stacks of red cells (like coin stack) due to changes in plasma protein
what are agglutinates
clumps (irregular stacks) of red cells due to antibodies (igM) on surface–> ^stickiness
what are howell jolly bodies
nuclear remnant in cell (dark purple spot in cell) can be caused by lack of splenic function
