blood part 2 white blood cells Flashcards
Leukocytes make up how much of blood volume
less than 1%
diapedesis
how leukocytes leave capillaries
Leukocytosis
WBC count over 11,000
Granulocytes
neutrophils, eosinophils, and basophils
Granulocytes description
Cytoplasmic granules stain specifically with Wright’s stain
Larger and shorter-lived than RBCs
Lobed nuclei
Phagocytic
Neutrophils
Most numerous WBCs crazy shaped nuclei Fine granules lilac color Granules contain hydrolytic enzymes or defensins Very phagocytic
Eosinophils
Bilobed nuclei (earmuffs)
Red to crimson lysosome-like granules
Digest parasitic worms that are too large to be phagocytized
Modulators of the immune response
Basophils
Rarest WBCs
Large, purplish-black (basophilic) granules contain histamine
similar to mastcells
Histamine
an inflammatory chemical that acts as a vasodilator and attracts other WBCs to inflamed sites
Agranulocytes
lymphocytes and monocytes
Agranulocytes description
no granules
Have spherical or kidney-shaped nuclei
Lymphocytes
Large, dark-purple, circular nuclei with a thin rim of blue cytoplasm (mostly nucleus)
Mostly in lymphoid tissue; few circulate in the blood
Crucial to immunity
Lymphocytes two types
t cells
b cells
T cells
act against virus-infected cells and tumor cells
B cells
give rise to plasma cells, which produce antibodies
Monocytes
The largest leukocytes
Abundant pale-blue cytoplasm
Dark purple-staining, U- or kidney-shaped nuclei
Monocyte functions
Leave circulation, enter tissues, and differentiate into macrophages
Actively phagocytic cells; crucial against viruses, intracellular bacterial parasites, and chronic infections
Activate lymphocytes to mount an immune response
monocytosis
abnormally high number of monocytes
monocytosis causes
stress, inflamation, severe infection
monocytopenia
abnormally low levels of monocytes
monocytopenia causes
aplastic anemia, HIV, lupus, damaged bone marrow, cancer treatments
Leukopoiesis
Production of WBCs
Stimulated by chemical messengers from bone marrow and mature WBCs
leukopoiesis chemical messengers
Interleukins
Colony-stimulating factors (CSFs) named for the WBC type they stimulate
All leukocytes originate from
hemocytoblasts
how leukocytes differentiate (the paths)
start with menocytoblast
then go to myloid stem cell or lymphiod stem cell
after myloid makes either eosinophils, basophils, neutrophils, or monocytes
after lymphoid stem cells make lymphocytes
Leukopenia
Abnormally low WBC count—drug induced
Leukemias
Cancerous conditions involving WBCs
Leukemias naming
Named according to the abnormal WBC clone involved
Myelocytic leukemia involves myeloblasts
acute leukemia
involves blast-type cells and primarily affects children
chronic leukemia
is more prevalent in older people
Platelets
Small fragments of megakaryocytes
Formation is regulated by thrombopoietin
Blue-staining outer region, purple granules
Granules contain serotonin, Ca2+, enzymes, ADP, and platelet-derived growth factor (PDGF)
platelet functions
Form a temporary platelet plug that helps seal breaks in blood vessels
Circulating platelets are kept inactive and mobile by
NO (nitrogenous oxide) and prostacyclin from endothelial cells of blood vessels
Increase in eosinophilias can indicate
Infection by parasitic worms, autoimmune disease
Increase in neutrophils can indicate
Bacterial infection
Pyogenic infections
Heart attack
Low basophils count can indicate
Allergic reaction
High basophils count can indicate
Blood cancer
Mediate inflammatory response
High number of lymphocytes can indicate
Inflammatory response
Infection
Virus and tumor cells
Increased number of monocytes Indicates
Chronic infections
Bacterial viruses
Parasitic bacteria
