Haematology 1 Flashcards
(42 cards)
What are agglutinates?
Describe its appearance and formation.
Agglutinates = formation of irregular clumps
Formation:
- usually results from antibody on the surface
- which makes red cells stick to each other
What is a main function of basophils
Has role in allergic response
Blood cells are derived from _____________
Multipotent lymphoid-myeloid stem cells
Describe the formation of platelets
Describe the main function of platelets
Multipotent haematopietic stem cells —> megakaryocytes —> platelets
- has role in primary haemostasis
- platelets also contribute to phospholipid (which promotes blood coagulation)
Multipotent myeloid stem cell in turn gives rise to:
a) ___________
b) ___________
c) ___________
a) granulocyte - monocytes
b) erythroid
c) megakaryocyte
What is meant by a left shift
Left shift = increase in non segmented neutrophils or an increase in neutrophil precursors in the blood
If there are many band form neutrophils in blood film —> left shift
- left shift suggests presence of infection
Lymphoid stem cell in turn gives rise to
a) _________
b) _________
c) _________
a) T cells
b) B cells
c) NK cells
Describe the formation of red cells
Erythropoiesis = Myeloid stem cell —> gives rise to proerythroblast –> which then gives rise to erythroblasts —> then erythrocytes/red cells
- requires erythropoietin (synthesised in kidney in response to hypoxia)
Blasts have in common :
Large nuclei
Small amount of cytoplasm
Note:
- as red cells differentiate cytoplasm goes from dark blue to more pink colour
-
Where does synthesis of erythropoietin occur?
- mainly synthesised in the kidneys (juxtatubular interstitial cells)
- small amount = in liver
Life span of erythrocytes
120 days
What is the definition of hyperchromia
Hyperchromia = cells lack central pallor
- can occurs if cells are thicker than normal
- or because their shape is abnormal
Define Polychromasia
Definition: increased blue tinge to the cytoplasm of a red cell
- blue tinge = indicates cells are young
- reticulocytes are stained with methylene blue
(Reticulocyte stain)
How are red cells destroyed?
Destroyed by phagocytise cells in the spleen
- red cells have extensive cytoskeleton (good at wriggling through holes in capillaries)
- as they get older they become less flexible
- less able to squeeze through wall
- so gets held up in spleen
- then destroyed
Definition of Poikilocytosis
Red cells show more variation in shape than is normal
Note
lymphocytes = reference to determine size of red cells
Usually, red cell is bit smaller than lymphocytes
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What is hypersegmented neutrophil?
What does it occur?
Hypersegmented neutrophils = increase in average number of neutrophils lobes or segments
- results from lacks of VIT B12 or folic acid
What are sickle cells?
Why does it occur?
Sickle cells = sickle or crescent shaped
- results from polymerisation of hbS (when it is present in high conc)
Pluripotent haematpoietic stem cells give rise to:
a) ____________
b) ____________
a) myeloid stem cell
b) lymphoid stem cell
What is toxic granulation
And why does it occur?
Toxic granulation = heavy granulation of neutrophils
(Granules become more denser)
- results from infection, inflammation and tissue necrosis
- it is also a feature of normal pregnancy
What are the 2 important types of hyperchromatic cells?
- spherocytes (very round)
- irregularly contracted cells (don’t show complete circle)
Describe the appearance of spherocytes.
And describe the formation of spherocytes.
Appearance:
- spherical shape
- round regular outline
- lacks central pallor
Formation:
- results from loss of cell memb without loss of equivalent amount of cytoplasm
- so cell is forced into spherical form
NOTE: You get spherocytes in hereditary spherocytosis
Describe the appearance of Irregularly contracted cells.
Describe the formation of irregularly contracted cells
Appearance:
- irregular outline
- smaller than normal cells
- lost central pallor
Formation:
- results from Oxidant damage to cell memb and hb
