Leukocytes Flashcards
Genesis of myelocytes
(Review)
Concentration of basophils
0.4%
Where a small portion of WBCs are found
Peripheral blood
Concentration of lymphocytes
30%
Other term for leukocytes
White blood cells
Formed elements
Platelets
Leukocytes
Erythrocytes
Percentage of neutrophils
50-70%
Where precursor cells are usually found
Bone marrow
Granulocytes
Neutrophil
Eosinophil
Basophil
Percentage of basophils
0.5-1%
Phagocytes
Neutrophil
Eosinophil
Basophil
Monocyte (macrophage)
3 compartments/locations
Bone marrow
Peripheral blood
Tissues
Concentration of monocytes
5.3%
Percentage of eosinophils
2-4%
Sixth type of leukocyte
Plasma cell
Based on presence of granules in cytoplasm
Granulocytes
Agranulocytes
Percentage of lymphocytes
25-45%
Percentage of monocytes
3-8%
Based on function
Phagocytes
Immunocytes
Where main function of WBCs ensues
Tissues
Concentration of eosinophils
2.3%
Functions of WBCs
1 Soldiers against infectious and toxic agents
2 Provide rapid and potent defense against any invader recognized as foreign
3 Play a role in innate and adaptive immunity
Leukocyte classification
Presence of granules in cytoplasm
Number of nuclei
Function
Based on number of nuclei
Polymorphonuclear
Mononuclear
Immunocytes
Lymphocytes (T dell, B cell, NK cell)
Mononuclear
Monocyte
Lymphocyte
Polymorphonuclear
Neutrophil
Eosinophil
Basophil
Stain used in WBC identification
Wright’s stain
Other term for primary granules
Azurophilic
Concentration of neutrophils
62%
Cytoplasmic characteristics
1 Color of the background
2 Presence or absence of granules
3 Color and size of granules
CBC measurements
WBC in thousands/mm3
Differential leukocyte count
Example of a leukocyte with high nucleus-cytoplasm ratio
Lymphocyte
Produce antibody and act in activities of the immune response
Immunocytes
Engulf and destroy
Phagocytes
Formed in thymus and other lymph tissues
Lymphocytes
Plasma cells
Non-granulocytes
Monocyte
Lymphocyte
Plasma cell
Leukocyte formation figure
(Review)
Routine method for identification of WBCs
Peripheral blood smear
Minimal affinity for acidic or basic dyes
Neutrophils
Reaction with methylene blue
Basophil
Nuclear characteristics
1 Shape
2 Color
3 Chromatin pattern
4 Presence or absence of nucleoli
Neutrophils move through tissue spaces by
Amoeboid motion
Indicates if leukocyte is mature or not
Nucleoli
Come from a common myeloid progenitor cell that is also the precursor of RBCs and platelets
Granulocytes
Life of granulocytes after release from bone marrow
4-8 hours
Macrophages destroy them after they have served their purpose
Granulocytes
Low nucleus-cytoplasm ratio interpretation
Nucleus is small in relation to the volume of the cytoplasm
Degrades glycopeptides and carbohydrate cell walls of bacteria
Lysozyme
Nucleus has 2 to 5 lobes joined by a solid filament
Neutrophil
Reaction with eosin
Eosinophil
Criteria for leukocyte identification
1 Cell size
2 Nucleus-Cytoplasm Ratio
3 Cytoplasmic characteristics
4 Nuclear characteristics
Neutrophil forms released in the bloodstream
Band cell
Segmented neutrophil
T or F. Neutrophils take one week to mature before they are released from the bone marrow.
T
Aid in killing bacteria
Granules
Granule content of basophils
1 Histamine 2 Sulphated mucopolysaccharides (mostly chondroitin sulfate; to digest bacterial cell wall) 3 Peroxidase 4 Chymase 5 Tryptase 6 Charcot-leyden crystal protein 7 Platelet-activating factor (PAF) 8 Eosinophil chemotactic factor of anaphylaxis (ECF-A)
Toxic forms of oxygen in lysosomes
Peroxidase
Superoxides
Contents of primary granules
1 Myeloperoxidase 2 Proteases (Elastase and Cathepsin G) 3 Lysozyme 4 Inactive forms of acid hydrolases 5 Bactericidal cationic protein
Neutrophils enter tissue spaces by
Diapedesis
Formed in bone marrow
Granulocytes
Monocytes
Few lymphocytes
Life of granulocytes in tissues
A couple of days
Function of neutrophils
Mediate immune response against infectious agents and organisms by attacking and destroying bacteria in the circulating blood
Neutrophils engulf offending agents by
Phagocytosis
Characteristics of a segmented neutrophil nucleus
1 2-5 lobes
2 Connected by a filament
3 Condensed nuclear chromatin
4 Pale cytoplasm with specific granules
Examples of leukocytes with low nucleus-cytoplasm ratio
Mature monocytes
Neutrophils
Contents of secondary granules
1 Lactoferrin
2 Lysozyme
3 Collagenases
4 Vitamin B12 binding proteins
High nucleus-cytoplasm ratio interpretation
Nucleus occupies most of the cell area with only a small rim of cytoplasm
Produce numerous regulatory cytokines
Eosinophils
Responsible for killing phagocytosed bacteria
Myeloperoxidase
Contents of quaternary granules
Secretory vesicles
Lymphocyte functions
1 Play a major role in the maintenance of health
2 Antigen recognition and generation of appropriate immune response
What will happen if continuous neutrophil production stops?
Death by sepsis
Presence of few primary granules and abundant secondary granules
Band
May contain Auer rods
Myeloblast
First post-mitotic myeloid precursor
Metamyelocyte
Neutrophils are attracted to inflamed areas by
Chemotaxis
Presence of rare primary and many secondary granules
Metamyelocyte
Cell-mediated immune response
T/NK cells