physiology of blood cells and terminology Flashcards
multipotent haematopeotic stem cells, what they form
give rise to lymphoid AND myeloid stem cells myeloid form granulocytes/monocytes, RBC and megakaryocytes lymphoid forms T, B and NK cells
characteristics of stem cells
can form mature cells OR self renew ie form more stemc cells
pathway of red blood cells- erythropoeisis
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
importance of erythropoetin
needed for erythropoeisis- kidney produces more when little oxygen present/ anaemia, increasing bone marrow activity= more RBC
production of erythropoeitin
90% in kidney by juxtatubular interstitial cells, 10% by liver by hepatocytes and interstitial cells erythropoeitin goes into capillary, then bone marow
red blood cells duration, function and breakdown
survives 120 days O2 and some CO2 transport (although most CO2 in plasma) destroyed in spleen
production of white cells +what it depends on
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
how to see if there are large number of reticulocytes in blood
either a reticulocyte stain, or look at red blood cells which are slightly bigger and are slightly blue (have more ribosomes- called polychromatic)
DIAGRAM neutrophil- lifespan, what it does and how it gets to tissue
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
eonisophil DIAGRAM
myeloblasts can also form this granulocyte - shorter lifespan thart neutrophils, and fights parasites by releasing granules
basophils DIAGRAM
also granulocyte formed by myeloblasts- needed for allergic responses
monocytes DIAGRAM
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
platelets
megakaryocytes are precursor- these are very large cells which fragment to form platelets platelets survive 10 days
lymphocytes lifespan
lifespan variable
define anisocytosis DIAGRAM
RBC show more variation in size than normal
define poikilocytosis DIAGRAM
RBC show more variation in SHAPE than normal
define microcytosis (thus microcyte)- comparison to lymphocyte
RBC smaller than normal ie microcytes RBC should be same size as lymphocyte nucleus normally- these are normocytic
define macrocytosis thus macrocyte
RBC larger than normal ie macrocytes
types of macrocytes
round, oval and polychromatic oval can indicate a vitamin B12 deficiency, polychromatic can suggest a haemmorhage or vitamin deficiency as well
DIAGRAM RBC on inside and outside
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
hypochromia DIAGRAM
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
hyperchromia and causes
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)
spherocytes cause
due to loss of cell membrane without loss of cytoplasm, so cell rounds up to enclose it occurs in hereditary spherocytosis
irregular contracted cells
due to oxidant damage to cell membrane and haemoglobin, causing clumbing
polychramasia and significance with limitation
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
types of poikilocytes
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)
target cells- what it is and causes
haemoglobin accumulates in central pallor often occurs in liver disease and obstructive jaundice
elliptocytes - when it occurs DIAGRAM
occurs in hereditary elliptocytosis (top) and iron deficiency (bottom- large central pallor)
sickle cells cause
due to polymerisation of haemoglobin S
rouleaux DIAGRAM
stacks of red cells like a pile of coins, due to changes in plasma proteins eg immunoglobulins
agglutinates
irregular clumps rather than stack of coins, due to antibodies on surface of cells
howell-jolly body DIAGRAM
remnant of a nucleus, due to lack of splenic function ie less breakdown
define leucocytosis, leucopenia, neutrophila, neutropenia, lymphocytosis and eonisophila
too many WBC, too few, too many neutrophils, too few, too many lymphocytes, too many eonisophils
define thrombocytosis, thrombocytopenia, erythrocytosis, reticulocytosis, lymphopenia
too many platelets, too few, increased number of RBC, increased no. of young cells, not enough lymphocytes
atypical lymphocytes and when it occurs
abnormal- often occurs in infectious mononucleosis
left shift DIAGRAM
increase in non-segemented (nucleus looks like a band, hasn’t separated) neutrophils ie more neutrophils, as production of neutrophils has shifted left
toxic granulation DIAGRAM
too much granulation of neutrophils, often due to infection
right shift DIAGRAM
where neutrophil is hypersegmented, so increase in number of nucleus lobes due to B12/folic acid deficiency
