Hematology- leukocytes Flashcards
leukocytes
- WBCs
- larger than RBCs
- make up less than 1% of total blood (white/clear stuff from blood centrifuge)
- can leave capillaries VIA diapedesis (leukocyte extravasation)
- they then move through tissue spaces by ameboid motion and positive chemotaxis (following scene of the chemical and concentration gradient)
diapedesis/extravasation
leukocyte changes shape and squeezes out of spaces between blood vessels
leukocytosis
too many WBCs (over 11,000 mm3)
normal response to bacterial/viral invasion
composition of leukocytes in the 45% of formed elements in hematocrit
granulocytes:
-neutrophils
-eosinophils
-basophils
agranulocytes:
-lymphocytes
-monocytes
composition of leukocytes in the 45% of formed elements in hematocrit
granulocytes:
-neutrophils
-eosinophils
-basophils
agranulocytes:
-lymphocytes
-monocytes
in order of most common to least common…
*never let monkeys eat bananas
neutrophils
lymphocytes
monocytes
eosinophils
basophils
granylocytes
neutrophils, eosinophils, and basophils
- larger and shorted lived than RBCs
- lobed nucleii
- phagocytic (they eat things)
neutrophils
- most numerous WBCs
- polymorphonuclear leukocytes (many shaped nucleii)
-fine granules take up acidic and basic dyes - give cytoplasm a lilac color
- granules contain hydrolytic enzymes
- very phagocytic (bacteria killers/eaters)
eosinophils
- bilobed nucleii
- red to crimson, coarse, filled with lysosome like granules
- digest parasitic worms too large to be phagocytized
basophils
- rarest WBCs
- large granules that contain histamine and heparin
- functionally similar to mast cells: inflammatory response
histamine and heparin
histamine: inflammatory chemical that acts as a vasodilator and attracts other WBCs to inflamed sites
heparin: anticoagulant
agranulocytes
lymphocytes and monocytes
- lack visible granules
- have spherical or kidney shaped nuclei
lymphocytes
- large, dark purple, circular nuclei with a thin rim of blue cytoplasm
- mostly found in lymphoid tissue (neck, armpits, groin), few circulate in blood until stress reponse
- 2 types:
t cells: act against virus infected cells and tumor cells
b cells: produce antibodies
monocytes
- largest leukocytes
- leave circulation, enter tissues, and become MACROPHAGES
- actively phagocytic: against viruses, parasites, and chronic infections
- activate lymphocytes to start immune response
monocyte levels
- monocytosis (aka mono): abnormally high levels of monocytes; caused by stress, inflammation, severe infection, necrosis
- monocytopenia: low levels; caused by aplastic anemia (no RBCs or WBCs, HIV, lupus, damaged bone marrow, cancer treatments)