week 7- WBCs Flashcards
(88 cards)
• What non-RBC info is in a CBC?
o WBC info: number of WBCs, WBC differential (WBC populations)
o PLT info: number of platelets, platelet volume (MPV)
• What is non-RBC composition of whole blood? Absolute #?
o Plasma: 46-63% o Formed elements: 0.1% platelets and WBCs o N: 55-70%, 2500-8000 o E: 1-4%, 50-500 o B: 0-2%, 25-100 o L: 20-40%, 1000-4000 o Monocytes: 2-8%, 100-700
• What is basic function of WBCs?
o defense system against infectious foreign invaders and non-infectious challenge. 2 separate events:
o Phagocytosis: Involves granulocytes and monocytes
o Development of a specific immune response: Involves monocytes (macrophages) and lymphocytes
• How do WBCs travel in body?
o vascular system is only a temporary residence
o main function of vasculature with respect to WBCs is to transport to body tissues.
• Where is bone marrow? Function? Types?
o production site for all hematopoiesis
o primarily in hollow parts of long flat bones like the sternum and hips
o red and yellow: Majority of RBCs, WBCs and platelets formed in red marrow.
• What are blood stem cells?
o Pluripotent: pluri = more + potential = power
o Refers to the ability of a cell to become many different types of cells
o 2 types of stem cells in bone marrow:
o Mesenchymal: connective tissue, blood vessels and lymphatic tissue
o Hematopoietic: blood cells: RBCs, WBCs, platelets
• How are WBCs differentiated from each other?
o by nuclear and cytoplasmic characteristics
o granulocytes, agranulocytes
• what are granulocytes
o The granules in eosinophils have affinity for the acid part of the Wright’s stain and they stain orange-pink
o Basophils, for the basic part of the stain, bluish-black.
o Neutrophils, for both acid and basic parts, pinkish-blue (purple)
• What are agranuloctes?
o Monocytes: usually large with a horseshoe shaped nucleus
o Lymphocytes may be small (non-reactive) with a large N:C or large (reactive) with a smaller N:C. The nucleus is usually round (small lymphs) or may be slightly indented (large lymphs).
• What stimulates production/maturation of all the different WBCs?
o All different types of cytokines
• What is the general morphologic maturation scheme of WBC/RBCs?
o First 4, for both WBC and RBC o Cytoplasm: more basophilia -> less o Large nucleus -> smaller o Larger nucleoli -> small -> absent o Large cell size -> smaller o 5th: WBC granulocytes only: o Nucleus large and round -> smaller and segments
• What are the 6 general stages of maturation following commitment of stem cell in bone marrow?
o Myeloblast: non-granular cytoplasm and red nucleus
o Promyelocyte: distinct granules
o Myelocyte: cell division possible through this stage, identified as n/e/b
o Metamyelocyte: slightly indented nucleus
o Band/ stab cell: indentation > ½ distance from farthest nucleus margin
o mature n/e/b: Segmented nucleus
• What precursor cells are not seen in normal blood smear? Seen?
o Not: Myeloblast, promyelocytes, myelocyte, metamyelocyte
o Seen: band cell; mature granulocyte
• What does a WBC count tell you?
o total WBC count and differential are measured in an automated counter
o reflects the circulating pool of myeloid and lymphoid cells
o WBC in each microliter (ml;mm3) is reported
• What are normal and bad WBC levels?
o > 2 yrs: 4500-10,000/mL
o 30,000
• What are low/high WBC counts called?
o High= >11,000; leukocytosis
o Low= <4000; leukopenia
• What causes leukocytosis?
o Infections o Leukemic neoplasia o Other malignancy o Trauma, stress, hemorrhage o Tissue necrosis o Inflammation o Dehydration o Thyroid storm o Steroid drugs o Post Splenectomy
• What causes leukopenia?
o Drug toxicity o Bone marrow depression/failure o Severe infections o Dietary deficiencies o Marrow aplasia o Marrow infiltration o Autoimmune disease o Hypersplenism o Chemotherapy
• Where do mature cells go?
o Normally only mature cells go into peripheral blood
o May also remain in storage in marrow
• What may be reason for increase/decrease in WBC count? How do you tell?
o May be d/t alteration of all WBC cell lines
o More commonly results from alteration of only one type of WBC
o Need differential=absolute values of each type, %
o *most variation in WBC count are due to inc/dec in # neutrophils, since by % they are most numerous
• How do you do a differential WBC count?
o Place one drop of blood onto glass slide, spread the drop & air dry.
o Wright’s Stain: A mixture of Methylene Blue basic dye and Eosin red-orange acidic dye.
o Phosphate buffer applied directly on top of stain, rinse, dry & examine.
o Oil immersion [100x] lens: count 100 WBCs
o This gives the RELATIVE # of each type of WBC, expressed as a percentage of the 100 cells counted.
• What are results of a Wright stain? Cell types?
o Cell structures with acidic groups bind the basic dye & appear blue.
o Cell structures with basic groups bind the acidic dye & appear various shades of pink or red-orange.
o Lymphocytes: scant cytoplasm
o Monocytes: ground glass cytoplasm
o Neutrophils: lavender
o Eosinophils: orange/red
o Basophils: blue/black
• What does a normal wright stained blood smear look like?
o Lots of purple RBCs, a few purple neutrophils with segmented purple nuclei
• What is normal WBC differential in newborn?
o WBC: 6-3000 o PMN: 42-80% o Band: 2% o L: 26-36% o Mono: 3-8% o E: 0-5% o B: 0-2%
