Objective 9 Leukocytes Granulocyte Agranulocyte Normal Values – less than 1% of total blood volume (rememebr the picture of the test tube!) Adults: 4800 – 10,800 leukocytes /mm3 blood (higher values in newborns, infants and children) B. Structure:  are nucleated  contain organelles  diameters range from 8 – 24 m  may contain cytoplasmic granules (agranulocytes vs. granulocytes) Granulocyte Agranulocyte

In what structural ways are leukocytes different than erythrocytes? In what functional ways are leukocytes different than erythrocytes? Where do they do their jobs?

Diapedesis – leukocytes leave capillary and enter tissue Chemotaxis – follow chemical signals to site of infection in the tissue

Neutrophil (also called a polymorphonuclear cell) Leukocyte Classes Granulocytes: Neutrophil (also called a polymorphonuclear cell)  diameter = 10-12 m  cytoplasmic granules stain pale lavender  lobed nuclei (3-6 lobes)  % of total leukocytes: 50-70% Granules contain lysosomal enzymes and defensins Neutrophils are quick acting phagocytes (1st responders) They are quick but weak! Typical Neutrophil Immature Cell - Band

Eosinophil  diameter = 10-14 m  large granules which stain red (major basic protein)  bilobed nucleus  represent 2-4% of the total WBC count Granules contain digestive enzymes Are antiparasitic Phagocytize immune complexes Anti-allergy

Basophil  diameter = 8-10m Granules contain:  large granules which stain blue  U or S shaped nucleus  0.5 – 1% of total WBC Granules contain: histamine which induces inflammation and vasodilation heparin an anticoagulant

Agranuloctes: lack visible cytoplasmic granules Lymphocyte:  diameter 5-8 m (small), 10-12 m (medium) or 14-17 m (large)  20-25 % of the total WBC count  large, deep blue or slightly indented nucleus  thin rim of pale blue cytoplasm T lymphocyte (T cells) fight antigens directly B lymphocytes (B cells) divide to produce plasma cells that secrete antibodies

Monocytes Are phagocytes – slow but strong  diameter = 18 m  nucleus is U shaped or kidney shaped  abundant pale blue cytoplasm  3 – 8 % of the total WBC Monocytes Are phagocytes – slow but strong Develop into when they migrate into connective tissue macrophages

Leukopoiesis is the production of leukocytes  all leukocytes can be made in red bone marrow from hemocytoblasts  lymphocytes can be made in either red bone marrow or lymphoid tissues  the production of lymphocytes is stimulated by interleukins and by colony stimulating factors (CSFs)

Objective 10 White Blood Cell Disorders circulating WBC count <4000/mm3 blood in adults increases the susceptibility to infection causes include bone marrow depression or destruction, often due to drugs, radiation, infection, or autoimmune conditions circulating WBC count is >11,000/mm3 blood in affected adults; is accompanied by bleeding, weight loss, liver/spleen/lymph node enlargement or immunosupression; suspect primary bone marrow disease causes include infection, inflammation, malignancy, allergic reactions, autoimmune disorders, genetic disorder, extreme stress, other causes Leukopenia Leukocytosis

Leukemia Classification: Cancer in which an excessive number of white blood cells is produced Classification: disease progresses rapidly disease progresses slowly Myelocytic involves cells in the myeloid pathway Lymphocytic involves cells in the lymphocytic pathway Acute Chronic

Causes: cancer in which an abnormally high number of WBCs are produced Symptoms anemia, fever, bruising/bleeding, bone pain Acute lymphocytic leukemia Chronic lymphocytic leukemia

Infectious Mononucleosis B lymphocytes are infected and proliferate in an uncontrolled manner signs include sore throat, fever, enlarged lymph nodes. Enlarged spleen, lethargy, fatigue cause: Epstein Barr Virus

Objective 11 Platelets Structure  are cell fragments  discoid in shape; diameter is 2-4 m  major internal proteins are actin and myosin What are actin and myosin used for?  cytoplasmic storage granules:  granules contain fibrinogen, factor V, factor VII, von Willibrands factor, platelet factor 4 and PDGF contain serotonin, Ca2+, adenosine nucleotides (ATP and APD), thromboxane A2 (a prostaglandin) contraction dense granules

platelets are produced in red bone marrow from megakaryotyctes Function: Platelet Production platelets are produced in red bone marrow from megakaryotyctes Hemostasis  Production is regulated by thrombopoietin and interleukins  Production takes 4-5 days; life span is 5-10 days

Average adult values: 150,000-400,000/mm3 blood spleen An additional 1/3rd is stored in the