Blood Flashcards
1
Q
Plasma
A
- Liquid extracellular matrix
- Liquid phase of unclotted blood (original fluid)
- Mostly water
- Liquid, cell-free portion of blood
- Many proteins (albumin)
2
Q
Relative Abundance
A
Erythrocytes(10^6) > Platelets(10^5) > Leukocytes (10^3)
Neutrophils(50%) > Lymphocytes(30%) > Monocytes(5%) > Eosinophils (5%)> Basophils (less than 1%)
Note: Until age 8, lymphocytes are the most common type of leukocyte
3
Q
Deviations from normal values
A
- Cytosis/philia = above normal
- Penia = below normal
4
Q
Hematocrit
A
-% blood volume occupied by packed erythrocytes after centrifugation
5
Q
Serum
A
-Plasma minus clotting factors (fibrinogen)
6
Q
Buffy coat
A
-Thin layer of leukocytes/platelets above red cells after centrifugation
7
Q
Blood Smears
A
-Romanovsky stains (Wright’s/Giesma)
8
Q
Methylene blue
A
-Nuclei, ribosomes, basophilic granules stain purple
9
Q
Azure dyes
A
-Azurophilic granules (lysosomes) stain reddish/purple
10
Q
Eosin
A
-Stains RBCs pink and specific granules of eosinophils red
11
Q
Reticulocytes
A
- Anucleate but contain few residual polysomes
- Small portion (1%) of circulating RBCs
12
Q
Brilliant cresyl blue
A
-Causes polysomes to clump in reticulocytes and stain darkly (reticulum network)
13
Q
Poikilocytosis
A
- Abnormalities in RBC shapes
- Caused by defects in cytoskeleton (spectrin)
- Defects in hemoglobin (sickle cell anemia)
14
Q
Anisocytosis
A
- Abnormalities in RBC size
- Macrocytes (abnormally large)
- Microcytes (abnormally small)
15
Q
Abnormalities in hemoglobin content
A
- Hyperchromic - more hemoglobin
- Hypochromic - less hemoglobin
16
Q
Anemia
A
- Decreased O2 carrying capacity
- Result of fewer blood cells or less hemoglobin
17
Q
Platelets
A
- Limits bleeding and promotes vessel repair
- Maintains intact endothelium
- Derived by fragmenting from megakaryocytes
18
Q
Thrombocytopenia
A
- Abnormally low platelet count
- Easy bruising, nosebleeds
- Petechial rash (small spots) or ecchymoses (large bruises)
- Idiopathic thrombocytopenic purpura (ITP) - antibodies destroy platelets
19
Q
Platelet morphology
A
- Hyalomere - clear outer region made of microtubules, actin filaments, microtubules that maintain shape
- Granulomere - basophilic stippling; contains 3 types of granules
20
Q
Platelet Alpha granules
A
- Platelet-derived growth factor (vessel repair)
- Von Willebrand factor (platelet adhesion to endothelium)
21
Q
Platelet Delta granules
A
- Ca2+, ATP, ADP (enhance aggregation)
- Serotonin (vasoconstriction; comes from plasma, not produced by platelets)
22
Q
Platelet Lambda granules
A
Lysosomal enzymes (clot removal)
23
Q
Membrane-bound channels
A
1) Open canalicular - invaginations of plasma membrane
2) Dense tubular - stores Ca2+ for exocytosis of granules, not continuous with membrane (similar to SER)
24
Q
Platelet-mediated events
A
1) Adhesion at site of damage
2) Aggregation to form primary hemostatic plug of platelets
3) Activation to stabilize plug and form secondary hemostatic plug; further aggregation and platelet shape change
4) Clot retraction to decrease size and restore blood flow
5) Clot resorption to remove clot
6) Vessel repair
25
Platelet adhesion
- Mediated by VWF binding to exposed collagen/laminin of damaged vessels
- Platelet activation normally absent in healthy vessels because underlying fibers (collagen/laminin) are not exposed to adhesion
26
Platelet aggregation
- Formation of primary hemostatic plug
- Fills in wall defect
- Fibrinogen links platelets together
27
Platelet activation
- Secretion of mediators stored in granules
- Synthesis/released of new mediators (thromboxane TXA2 from arachidonic acid)
- Changes in platelet shape
- Further platelet aggregation, vasoconstriction, and coagulation
- Formation of secondary hemostatic plug with fibrin stabilization
28
Platelet clot retraction
-Platelets contract and decreases clot size to reestablish blood flow
29
Platelet clot resorption
-Lysosomal enzymes from lambda granules remove clot
30
Platelet vessel repair
- Alpha granules release platelet-derived growth factor
| - PDGF induces mitosis for repair/mitosis
31
Prostacyclin (PGI2)
- Derived from arachidonic acid
| - Inhibits platelet aggregation
32
Thromboxane (TXA2)
-Vasoconstriction and platelet aggregation
33
Cyclooxygenase pathway
- Platelet pathway - produced thromboxane (TXA2) for vasoconstriction and platelet aggregation
- Endothelial cell pathway - produces prostacyclin (PGI2) and inhibits platelet aggregation
34
Clotting pathologies
- Von Willebrand's Disease - Deficiency in VWF leading to lack of adhesion
- Bernard Soulier Syndrome -No VWF receptor leading to lack of adhesion
- Glanzmann's Thrombasthenia - deficiency in fibrinogen receptor leading to lack of platelet linkage
35
Granulocytes
- Contain abundant cytoplasmic granules (vacuoles)
- Contain azurophilic and specific granules
- Lobulated heterochromatic nucleus
36
Agranulocytes
- Contain few azurophilic granules but no specific granules
| - Non-lobulated nucleus
37
Leukocyte Adhesion Molecules
- L selectins on leukocytes
- Integrins on leukocytes
- P/E Selectins on inflamed endothelial cells
38
Leukocyte Adhesion Deficiencies
- LAD 1- lack of integrins on leukocytes
- LAD 2- lack of leukocyte receptors for P/E selectins
- Both result in decreased diapedesis, leukocytosis, infection
39
Chemotaxis
-IL-8, C5a, N-Formyl-methionine
40
Basophil function
- Degranulation increases permeability of vessels
| - Can cause allergies (hypersensitivity)
41
Basophil Morphology
- Least lobulated nucleus
- Heterochromatic nucleus
- Intensely basophilic with Romanovsky stains
- Azurophilic granules and very large specific granules
42
Basophil Activation
- IgE binds receptors on basophils and can bind antigens from basophil
- Degranulation of specific granules (histamine, eosinophil/neutrophil chemotactic factor, proteases)
- IL 4/13 secretion
- Platelet-activating factor (PAF), Leukotriene C4 (LTC4)
43
Basophil Mediator Effects
- Vasodilation/permeability by histamine/PAF/LTC4
- Contraction of airway smooth muscle by histamine/LTC4
- Increased mucus secretion by goblet cells/mucous glands by histamine
- Activation of B Lymphocytes/Class switching by IL-4/13
- Chemotaxis of eosinophils/neutrophils by ECF/NCF
- Itching by histamine
44
Eosinophil Function
- Kill larvae of certain parasitic worms (helminths)
- Phagocytosis of antigen-antibody complexes
- Modulation of basophils/mast cells
- Specific granules (MBP, ECP, EPO, EDN) and Respiratory burst (ROI/RNI)
45
Eosinophil Morphology
- Bi-lobed (sometimes 3) and heterochromatic
- Azurophilic granules and many large specific granules
- Eosinophilic granules (LM)
- Contain crystalloid in EM (Major basic protein)
46
Eosinophil Activation
- Cross-linking of IgA bound to their plasmalemma
- Cleave lipids to synthesize LTC4 and PAF
- Respiratory Burst (ROI/RNI)
- Degranulation
- Cytokine secretion
47
Neutrophil Functions
- Highly phagocytic cells; good at killing bacteria
- Promote inflammation
- Can produce pus
48
Neutrophil Morphology
- Heterochromatic nucleus with most lobes (2-5) connected by thin strands
- More than 5 lobes = hypersegmented neutrophils
- Inactivated X chromosome (Barr body) sometimes visible (drumstick poking out shape)
- Azurophilic granules/specific granules both small
- Histochemically stained for myeloperoxidase
- Very little Golgi when mature (only produce granules during bone marrow differentiation)
49
Neutrophil Azurophilic Granules
- Myeloperoxidase produces HOCL (bleach) from H2O2
- Bactericidal Permeability-increasing protein (BPI) damages membranes of gram-negative bacteria
- Lysozyme attacks gram-positive walls
- Defensins form pores
- Elastase attacks basement membrane
50
Neutrophil Specific Granules
- Lysozyme
- Lactoferrin binds free iron to starve bacteria
- Type IV Collagenase attacks basement membrane
51
Chediak-Higashi Syndrome
- Targeting defect to azurophilic granules
- Cannot kill bacteria
- Abnormally large vacuoles resulting from fusion of azurophilic granules with one another that are nonfunctional
52
Monocyte (macrophage) Function
-Removal of apoptotic cells
53
Monocyte Morphology
- Largest leukocytes
- Irregularly (U shaped) nucleus folded on itself
- Lacy chromatin ("moth-eaten")
- Pale nucleus and cytoplasm
- No specific granules
- Large pale vacuoles (phagosomes)
- Well developed Golgi produces azurophilic granules throughout lifespan
54
Macrophage Morphology
- Larger and more phagocytic than monocytes
- Contain phagocytized material in phagosomes
- More irregular nucleus than monocyte
55
Macrophage Activation
- Classical activation by IFN gamma from Th cells leads to increased phagocytosis
- Alternative activation by IL-4/IL-13 produces anti-inflammatory mediators and phagocytosis of apoptotic cells
56
Lymphocytes
- Represent 25-30% of blood leukocytes but 99% of cells in lymph
- Diapedesis through HEVs
- Able to recirculate for immune surveillance
57
Lymphocyte Morphology
- Small, medium, or large, depending on state of activation in immune response
- 90% in blood are small and inactive in immune response
- Small lymphocyte nucleus is round/kidney shaped and highly heterochromatic
- No specific granules
- Blast transformation results in enlargement of cytoplasm and a "smudged" euchromatic nucleus
58
Russell Body Cells
- Old plasma cells
| - Large, distended, RER cisternae (Russell bodies) full of antibodies and stain very eosinophilic
59
Natural Killer Cells
- Larger than inactive T or B cells
| - Contain more azurophilic granules visible by LM
60
LAD-1
- Deficiency of integrin expression for leukocytes
| - Decreased diapedesis, increased leukocyte counts
61
LAD-2
- Deficiency in P/E selectin receptor expression for leukocytes
- Decreased diapedesis, increased leukocyte counts
