Other Flashcards
Function of neutrophils
Ingest and digest bacteria, releases ROS and enzymes
Function of eosinophils
Attacks helminths, release peroxidase, ribonuclease, deoxyribonucleases, lipase, plasminogen and major basic protein
Function of basophils
Releases heparin for anticoagulation, histamine for vasodilation
Function of monocytes
Phagocytosis, APC, cytokine production
Lifespan of neutrophils?
3-6 hour lifespan
Neutrophils differentiate from _____ in bone marrow (same as RBCs).
Myeloid precursors, takes 7-10 days
How long does it take until myeloid precursors differentiate into neutrophils?
7-10 days
Myeloblast
Minimally granulated, scant cytoplasm, prominent nucleolus (correlates with ribosomal RNA pumping out tRNA, more primitive)
Promyelocyte
Abundant primary granules
Myelocyte
Secondary or “specific” granules (for specific pathogens)
List stage progressions of cells maturing.
1) Myeloblast
2) Promyelocyte
3) Myelocyte
4) Matured non-dividing cells
IL-3 function/effects
IL-3 affects many marrow tissues and provides proliferative and survival signals.
Also stimulates the growth of multiple myeloid cell types, involved in delay type hypersensitivity.
GM-CSF (Granulocyte macrophage-colony stimulating factor) function
GM-CSF promotes proliferation and differentiation of myeloid progenitors and monocytes
G-CSF (Granulocyte-colony stimulating factor) function
G-CSF stimulates growth of neutrophilic progenitors, acts in synergy with IL-3 on primitive myeloid cells and activates mature neutrophils.
Directs negative feedback regulation.
Clinical use of G-CSF and GM-CSF?
Raises neutrophil count and reduce the incidence of sepsis
T and B cells histological appearance?
Small (slightly bigger than RBC), mononuclear cells.
Unable to distinguish T cells from B cells by morphology
NK and CD8+ T cells histological appearance?
Large granular lymphocytes
Function of platelets in thrombus formation
Form a haemostatic plug and initiate thrombus formation
Thrombocytopoiesis
Thrombus formation
Describe formation of hemostatic plug
Collagen receptor on platelets bind to collagen, release substances that attract other platelets, which release clotting agents
How do platelets repair microscopic vascular damage that occurs daily?
Via VEGF, PDGF and TGF-beta release at sites of vascular injury.
Platelets are derived from?
Megakaryocyte-erythryoid progenitor (MEP)
Endomitosis
Keeps dividing and not separating so it becomes large (up to 128N compared to the normal 2N, huge amount of DNA)
Platelets also bind to the ____ receptor.
TPO receptor (c-Mpl)
TPO is produced in the?
Produced in the liver and kidney - secreted constitutively
Once platelet is bound to the TPO receptor, what happens?
Conformational change in the homodimeric receptor stimulates the cytoplasmic tyrosine kinase JAK2 which activates the STAT-5 pathway which stimulates proliferation and differentiation of haemopoietic stem cells and megakaryocytic/platelet progenitors
Tyrosine kinase JAK2 activates?
Activates the STAT-5 pathway
Activation of STAT5 pathway stimulates?
Proliferation and differentiation of haemopoetic stem cells and megakaryotic/platelet progenitors
Platelets bind free TPO and degrade it, but when platelet count is low?
Less TPO removed, so more is available to stimulate megakaryocyte production
Composition of plasma
Mostly water (90%) and soluble clotting factors (fibrinogen; factor 13, von Willebrand factor, factor 8; vitamin K-dependent coagulation factors 2, 7, 9 and 10)
Plasma can last how long in storage?
1 year at -18 degrees
What can plasma test indicate?
- Multiple acquired coagulation factor deficiency
- Inherited single plasma factor deficiency for which no coagulation factor concentrate exists
- Liver failure
- Massive transfusion
- Thrombotic microangiopathies, diffuse alveolar haemorrhage and catastrophic anti-phospholipid syndrome
Group AB plasma is?
Universally compatible with all patients
Group O plasma is only compatible with?
Patients with group O RBCs
Cryoprecipitate?
This is a distilled version of the plasma clotting factors
RH intravenous immunoglobulin is for?
Prevention of D antigen alloimmunization
Therapeutic effect of RH intravenous immunoglobulin?
Therapeutic effect is thought to be caused by antibody feedback with T-cell suppression of the B-cell clone responsible for the formation of anti-D antibody
