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LeukocytesFormation, Function and PathologyClinical PathologyKristin M. Canga, RVTLeukopoiesisAll WBC production starts out in red bone marrow from the same _____________________ ______ _______ that produces RBCs.

The ____________ that act on the PPSC determine which cell type will be produced.

Each WBC has its own stimulus for production.

All WBCs differentiate and develop in the bone marrow except for some _____________________ which start out in bone marrow but develop elsewhere.

At the beginning of leukopoiesis, all WBCs ___________________ (in the bone marrow)

PPSC = Pluripotent stem cell2Leukopoiesis

Granulopoiesis1. Stem cell 2. Myeloblast

3. Promyelocyte 4. Myelocyte

5. Metamyelocyte 6. Band cell

7. Mature cell (segmented neutrophil, basophil or eosinophil)

Classification of LeukocytesLeukocytes may be classified in three different ways:______________________________________________________________________________________________________________________________________Classification by Defense Function____________________________Phagocytic leukocytes include:_________________________________________________________________________________________________________________________________ production and cellular _______________________________________

Classification by Shape of Nucleus_____________________________Means that the nucleus is _________________, or __________________NeutrophilsEosinophilsBasophils_____________________________Means that the nucleus is varying in ___________ and ______________________Monocytes_____________________________Means that there is a _____________, rounded nucleusLymphocyte

Classification by Granules____________________(Presence of granules)________________ granules not attracted to stain________________ granules attracted to acidic stain________________ granules attracted to alkaline stain____________________(Absence of granules)________________________________More on GranulocytesOriginally no granules presentPPSC _________________, _________________, __________________, __________________, and finally the various granulocytes based on _________________ granules._____________________ produces first set of granules as cells matureFirst set are called _______________________granulesGolgi Apparatus also produces granules that are attracted to stain__________________ granules are added as cell matures to determine ____________________ of the cell.

Functions of the Specific GranulesSpecific Granules contain different substances depending on the cell:Neutrophil granules contain ____________________Aid the cell in killing microorganisms after ___________________Eosinophil granules contain __________________________________________De-granulate at site of allergic or anaphylactic reaction to reduce swellingBasophil granules contain ___________ and _________Histamines are released to initiate ___________________ at site of reactionInflammation draws ____________________ to site_________________ acts as local anticoagulant to keep blood flowing to injured/damaged area.

Details of the GranulocytesRecall that the granulocytes include:_______________________________________________________________Granulocytes - NeutrophilsAlso called polymorphonuclear cellsLobes of the ____________ are connected by thin ________________ As cell ages, the chromatin of the nucleus ______________ (squeezes together) and changes shape. (Think ________ and __________)As cell becomes ____________, the segments break apart, losing all evidence of chromatin. (Indicates dead cell)Neutrophil FormationAdult neutrophils take ~___-___ days to be produced by the bone marrowAre being produced for release as circulating neutrophils migrate to __________ to fight microorganisms or die of old age.If high ___________ for neutrophils occurs, they can be produced in less time.Neutrophil CharacteristicsGranules are considered to be ________ because they stain neither red, nor blueOften identified on blood smear based on shape of ______________.PMN adult cells may contain between 2-4 lobes connected by thin filaments of _____________. Sometimes the chromatin is so thin that segments look separated.(your book says 2-5 lobes, either is fine.)Neutrophil FunctionNeutrophils only spend ~____ hours in circulation before migrating to __________.Once in the tissue, neutrophils do not ________________ circulation For this reason, the entire population of circulating neutrophils needs to be replaced ~________ times daily. If demand is so high that bone marrow cannot supply enough adults, ________ cells will be releasedIf demand is still too high, progressively _______________ cells will be released.

Neutrophil FunctionFirst line of defense in the bloodMajor function is __________________ of invadersCan respond to foreign microorganisms very quickly.Use the blood as _________________, squeezing through endothelium cells via ______________. (PLEASE review Figure 9-5 on pg 234 of A&P book)

Diapedesis = Pseudopod formation that pushes between endothelial cells of capillary, taking cytoplasm and rest of cell with it into tissue.15Neutrophil FunctionAttracted to site of infection by ______________Chemotaxis is the chemical reaction created between the microorganisms and the tissues that ____________cells.__________________ cells with granules that contain __________________.Lysosomes contain _______________ enzymes capable of destroying bacteria and viruses upon phagocytosis.Membrane flows around invader and encases it in vacuole that is created, allowing lysosomes to digest invader.____________ is produced through increased _____ absorption, and is toxic to invaders AND ______________.

Cell rapidly absorbs O2 and forms killing zone resulting in H2O2 16Neutrophil FunctionNormally found in tissues that are constantly susceptible to invasion by microorganisms such as the ________ and _____________tract.Dead or abnormal neutrophils are disposed of by tissue __________________.

Normal Neutrophil Count in BloodThe neutrophil count in peripheral blood is kept within a specific range (dogs: 3,000 11,400/L; cats: 2,500 12,500/L) in healthy animals and is controlled by three factors:

1) Release of mature neutrophils from the ______________ pool in the bone marrow into ________________________blood.

2) Rate of ______________ from peripheral blood into tissue.

3) Entrance of increase numbers of __________ into the neutrophil _________________ line.Maintaining Normal Neutrophil Pools1) Release of mature neutrophils from the ____________ pool in the bone marrow into the ________________ blood.________________ supply of mature neutrophils are on call and ready for __________________ release.Caused by sudden __________________ movement of neutrophils into _____________.

Maintaining Normal Neutrophil Pools2) Rate of ___________ from peripheral blood into ____________.Total neutrophil population in peripheral blood can enter the ___________ within a couple of hoursTriggered by massive acute _____________

Maintaining Normal Neutrophil Pools3) Entrance of increased numbers of _________ into the neutrophil ______________ line._________ method of control; it takes 3 to 6 days for neutrophils to mature for release

Intravascular Pools of NeutrophilsThe ______________________________(CNP)Refers to the blood contained in the ____________________________. Blood samples obtained for _______________ analysis contain neutrophils from this pool.The normal range for neutrophils is based on those contained in this pool. The _____________________________ (MNP)Composed of neutrophils that line the _________ of small blood vessels (not _______________________).These neutrophils are not contained in blood sampled for laboratory analysis.

NeutrophiliaDefined: An ______________ in neutrophils in blood circulationIf overall neutrophils increase, total ________ count increases causing __________________To meet increased demand for neutrophils in tissue, the bone marrow releases its reserve stores of mature, and if necessary, _______________ neutrophils into the blood.If a blood sample is drawn while these neutrophils are in transit, a ___________ than normal number of neutrophils will be included in the sample (__________________)

Neutrophilia in a Periperal Blood Sample

Neutrophilia and Stress_____________________ leukocytosis: Caused by exercise, ___________, or ________________ __________________ release results in a shift of neutrophils from the MNP to the CNP (_______________________)No left shift occurs (no increase in _______ cells)Count usually not more than ________ the normal valueShould return to normal within ___ minutes of removal of stimulusMost common in _________ and animals