Unit 7 - Leukopoiesis I Flashcards
Leukopoiesis
Development of all types of WBC in the bone marrow
Polymorphonuclear cells
Neutrophils
Eosinophils
Basophils
All WBC except __ fully develop in the marrow
T lymphocytes
Newborn WBC reference interval
9-30 x 10^9/L
First week of life WBC reference interval
5-21 x 10^9/L
WBC levels decline with aging
Not true
By what age are WBC at adult levels
8 years
Adult WBC reference interval
4.5-11x10^9/L
Leukocytosis
High level of WBC
Leukopenia
Low levels of WBC
WBC distribution - Neutrophils
40-80%
up to 5% bands
WBC distribution - Lymphocytes
25-35%
WBC distribution - Monocytes
2-10%
WBC distribution - Eosinophils
0-5%
WBC distribution - Basophils
0-1%
What is the best way to diagnostically evaluate WBC
Absolute count, compensates for low/high WBC
Absolute WBC count formula
% cell type X WBC total
Normal neutrophil absolute count
1.7-7.0 x 10^3 PMN/uL
Neutrophils combat
Bacteria
Eosinophils are able to..
Weak phagocytes
Attack parasite toxins
chill out allergic reactions
Overall function of granulocytes
Phagocytosis & Digestion of pathogens
Overall function of monocytes
Non specific
Phagocytosis
Antigen presentation to T cells
Granulopoiesis process
PSC
GEMM
Progenitor committed stem cell
Recognizable precursors
Neutrophil precursors
Myeloblast
Promyelocyte
Myelocyte
Metamyelocyte
Band neutrophil
Segmented neutrophil
Myeloblast key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
Large - 15um
High N/C ratio
Purple nucleus
Blue cytoplasm
NO granules
2-5 nucleoli
Fine, even chromatin
Golgi not very visible
Promyelocyte key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
CAN be larger than promyelocyte
12-20 um
High N/C Ratio
Primary, non-specific granules
Chromatin more coarse
Nucleoli less distinct
Myelocyte key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
15 um
Primary and specific granules
Nucleus on one side and flat
Chromatin more clumped
Nucleoli not visible
N/C ratio smaller
Last stage that can mitose
What is the last neutrophil precursor that can mitose
Myelocyte
Metamyelocyte key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
14 um
Nucleus begins to indent
Chromatin more clumped
Band key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
Nucleus indented more than 1/2 its width
Chromatin very clumped
Seg Neutrophil key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
Nucleus very clumped, separated into lobes
Connected by thin strand
3-5 lobes normally
How many segs does a normal neutrophil have
3-5 lobes
Eosinophil and Basophil maturation stages
Myeloblast
Promyelocyte
Eo/Basophillic myelocyte
Eo/Basophillic metamelocyte
Eo/Basophillic band
Eo/Basophilic segmented, 1-2 lobes
How many lobes do eosinophils and basophils have
1-2
Where are mast cells found
Bone marrow and tissues
not blood
How long are neutrophils in the bone marrow for
7-8 days total
How long are neutrophils in the mitotic pool for
2-3 days
Myeloblast –> myelocyte
How long are neutrophils in the storage pool for
5-7 days
Metamyelocyte –> segmented
How long do neutrophils stay in the PBS
7-10 hours
How are leukocytes attracted to invaders
Chemotaxis
Explain the process of diapedesis
Attraction by chemotaxis
Adhesion to vessel walls
Diapedesis through walls into tissue
Phagocytsis of infectious agent
Explain phagocytosis of neutrophils
Attraction by chemotaxis
Binding to surface by receptors
Pseudopodia eat microbe –> vacuole
Granules fuse with vacuole and release contents
Requires energy from glycolysis
Usually results in death
What is the unique granule in neutrophilic line
Myeloperoxidase
What are other fxns of neutrophils
Activate coagulation system
Interact with kinin system (coagulation)
Secrete IL-1 to induce fever
What granulocyte other than neutrophils are technically capable for phagocytosis
Eosinophils
Basophils
Basophils have receptors for
IgE
When a basophil s bound to IgE, wha is released
Histamine release –> immediate hypersensitivity
How do basophils function in the coag system?
Via heparin granules
Monocyte hematopoiesis
Monoblast
Promonocyte
Mature monocyte
Monoblast key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
Indented nuclei
Nucleoli visible
Cytoplasm grayish blue
May have vacuoles
More abundant cytoplasm than myeloblast
Promonocyte key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
Slightly more mature with indented or folded nucleus
Mature monocyte key features
(size, N/C ratio, cytoplasm, nucleus, granules, nucleoli, Golgi)
Cytoplasm - grayish blue, fine granules (ground glass), blunt pseudopods, vacuoles common
Larger than neutrophil
Nucleus folded or indented or convoluted
Chromatin has dark and light areas versus lymphocyte with dense clumping
How long do macrophages live in the tissues
Months
Functions of macrophages
Vacuum cleaner
Immune responder
Specialized fan in specific issues
What do monocytes do in peripheral blood
Patrol along vessel walls
Respond to inflammation –> diapedesis –> tissue becomes macrophage
How do monocyte marginal pools differ from PMNs?
3x larger
Mono/macro phagocytosis
Attracted to site by chemotaxis
Necrotaxis - attn to dead cells
Phagocytosis
Which leukocytes function in cellular immunity
Lymphocytes
monocytes
How do monocytes aid in cellular immunity
Phagocytize cells with intracellular bacteria and present the epitope to T cell
Tumor cells
Late stages of bacterial invaders
Monocytes
Initial stages of bacterial invaders
Neutrophil
Contents of monocyte/macrophage lysosomal granules
Phosphatases
Esterases
Lysozyme
Arylsulfatase
Contents of neutrophil granuels
Lysozymes
Myleperoxidase
