Unit 1 Flashcards

Question

Describe pinocytosis

Answer 1

- the uptake (engulfment) of liquids by the formation of tiny vesicles from the cellular membrane and their subsequent pinching off. - literally “ cell drinking”

Answer 2

- engulfment and destruction of particles- the vacuole containing the particle is fused with lysosomes and digestive enzymes are emptied into the vacuole for it destruction - cellular eating - cell ingests solid particles and digests them

Answer 3

- size and shape of cells constant but features can vary because of infectious diseases or malignancy

Answer 4

Bizarre cytologic features associated with poorly differentiated malignant tumors

Answer 5

- decrease in number or size of cells - leads to decrease in size of organ or tissue mass

Answer 6

Abnormal cytologic features - often is a premalignant change

Answer 7

Increase in number of cells in a tissue

Answer 8

Increase in size of cells - leads to increase in organs size

Answer 9

Change from one adult type to another

Answer 10

The death of groups of tissue cells caused by environmental factors such as lack of oxygen

Answer 11

Functional units of a cell that can only be viewed with an electron microscope. - staining with Wrights stain aids in differentiating features of the cells

Answer 12

- 70-90% water - contains proteins, lipids, carbohydrates, minerals, salt and water - background for all chemical reactions that takes place in the cell - embedded in cytoplasm are the organelles

Answer 13

- centrioles - endoplasmic reticulum - Golgi apparatus - lysosomes - microbodies - microfilaments - microtubules - mitochondria - ribosomes

Answer 14

- involved in cell division - two cylindrical organelles found near the nucleus in a tiny round body called centrosome - they serve as points of insertion of the spindle fibers during cell division - has 9 (triplet) groups of microtubules

Answer 15

- separate from each other - form thin cytoplasmic spindle fibers that connect to each individual chromosome - pull apart to help equal distribution of chromosomes into two daughter cells

Answer 16

- lace like network, two kinds: —> rough —> smooth - network of tubular structures crisscrossing across the cell - some connect the nuclear membrane to the cell membrane - channel for transport - acts as a storage area

Answer 17

- containing ribosomes - protein production

Answer 18

- no ribosomes present - site of lipid synthesis (cholesterol) and breakdown of fats into smaller molecules that can be used for energy

Answer 19

- appears unstained area next to nucleus - arranged in layers of membranes resembling stacks of pancakes - part of the Golgi apparatus and adjacent portions of the ER produce lysosomes - products of Golgi apparatus are exported from cell when a vesicle fuses with the plasma membrane - horseshoe-shaped or hook-shaped organelle with associated stack of vesicles

Answer 20

1) it is the site for concentrating secretions of granules, packing and segregating carbohydrate components of certain secretions 2) synthesizes carbohydrates and combines them with proteins 3) abundant in gastric glands, salivary glands, and pancreatic glands

Answer 21

- contain hydrolytic enzymes for digestion of phagocytized products, waste management of the cell - digest protein molecules - helps to digest old, worn-out cells, bacteria and foreign matter - If they rupture, the lysosome will digest the cell’s proteins causing it to die - “suicide bags” - three types: primary, secondary, and tertiary

Answer 22

- small intracytoplasmic organelles - contain oxidase enzymes that produce H202 (hydrogen peroxide) - oxidative activity is important aspect of phagocytosis

Answer 23

- consists of protein actin and larger myosin filaments - AIDS in amoeboid movement of phagocytic cells - smallest components of cytoskeleton.

Answer 24

- hollow protein fibers— formation is rapid, reversible self assembly of filaments function: —> cell shape- cytoskeleton —> organelle movement —> passive role in intracellular diffusion - mitotic spindle is composed of microtubules

Answer 25

- rod-shaped, energy producing organelles - makes energy in the cell - cells that have the most mitochondria have a greater need for energy - contain enzymes that break down glucose to ATP (adenosine triphosphate) the energy molecule - “powerhouse” - not found in mature erythrocytes

Answer 26

- small dense granules that contain RNA and protein - exist singly or in clusters in cytoplasm or on ER (making it rough ER) - site of protein synthesis (with mRNA) - show lack of membranes - presences of many ribosomes produces cytoplasmic basophilia (blue color) when stained with Wright stain

Answer 27

- storage form of carbohydrate - can be seen with special stain periodic acid-Schaffer (PAS) - increased glycogen concentrations in neutrophils related to need for high energy to carry out of body defenses

Answer 28

- storage form of iron - found in telolysosomes (iron-rich dense bodies) - siderosomes is term used to refer to iron-saturated hemosiderin - found in macrophages of spleen and bone marrow - plays role in recycling and storage of iron for hemoglobin synthesis - smaller than glycogen

Answer 29

- 10-15 um - control center of cell - membrane has inner and outer layer, outer layer continuous with ER - contains one or more nucleoli which contains RNA and is site of synthesis and process of the different types of RNA - contains chromatin- uncoiled DNA

Answer 30

- genetic material composed of nucleic acids and proteins - DNA has two functions - proteins associated with nucleic acids —> histones —> nonhistones —>together = nucleosome - demonstrates characteristic patters when stained - distinctive feature of cell types - divide into two types —> heterochromatin —> euchromatin

Answer 31

1) dictate nature of proteins that can be synthesized- controlling cell 2) transmit information for cellular control from one generation to next

Answer 32

- positively charged - essential to structural integrity to chromatin

Answer 33

- Less positively charged - play role in genetic regulation and organization of DNA and histones

Answer 34

- condensed, dark staining area - genetically inactive - associated with nucleolus - more restricted function of a cell the more heterochromatin present

Answer 35

- uncoiled, pale-staining area - genetically active

Answer 36

- genetic material that exists as diffuse elongated chromatin fibers prior to mitosis - during cellular division that stands condense into short visible structures - number is constant within each species —humans have 46 chromosomes arranged into 23 pairs, one member of each pair inherited from the father and the other inherited from the mother - 22 pairs are autosomes (body chromosomes) and pair represents the sex chromosomes, either XX or XY - chromosomes can be grown, harvested, stained, and banded to produce a Karotype

Answer 37

1) deletion 2) translocation 3) trisomy

Answer 38

Loss of a segment of a chromosome

Answer 39

Segment of one chromosome breaks from its normal location and attaches to another chromosomes during meiosis

Answer 40

- One of the homologous chromosomes fails to separate from its sister chromatid and leads or a set of three chromosomes instead of a pair - trisomy 21 = Down syndrome

Answer 41

1) interphase: DNA replication 2) prophase: chromatin coils: nuclear membrane disintegrates, centrioles move to opposite ends of the cell 3) metaphase: chromatids move to equatorial plate 4) anaphase: chromatids separate and move to opposite poles 5) telophase: two daughter cells form and nucleolus and nuclear membrane reappear

Answer 42

1) cell division unique to gametes 2) gametes have only one homologous of the 23 pair (haploid number 1n) 3) phases differ from mitosis- two cell divisions 4) during phase I of meiosis— homologous sister chromatids undergo process of synapsis (lining up end to end) to allow for crossing over- an exchanging of genetic information

Answer 43

Glycogen Ferritin

Answer 44

- refers to stable changes in gene function that are transmitted from from one cell to its progeny - epigenetic changes play important role in normal cellular development and differentiation

Answer 45

Total genetic material stored in an organisms chromosomes

Answer 46

Contributes to understanding inborn or acquired genetic problems by providing providing a low-power screening method for detecting isolated or missing chunks of chromosomes

Answer 47

Molecular methods

Answer 48

Abnormalities in: - erythrocytes - leukocytes - coagulation factors

Answer 49

- sickle cell disease - Alpha- and Beta- thalassemias

Answer 50

- acute myelogenous leukemia (AML) - acute lymphoblastic leukemia (ALL) - chronic myelogenous leukemia (CML) - lymphoma

Answer 51

- hemophilia A - hemophilia B - factor V Leiden defect

Answer 52

- chromosomes pairs are numbered according to relative size and position of their centromeres and placed in groups according to letters

Answer 53

- digestion of chromosomes with the enzyme trypsin, followed by Giemsa staining, that produces G bands

Answer 54

- First chromosomal abnormality discovered in a malignant disorder - example of translocation from chromosome 22 to 9

Answer 55

Interphase

Answer 56

- G1 - S phase - G2

Answer 57

- lasts 6-8 hours - nucleolus (nucleoli) becomes visible - chromosomes are extended and active metabolically - cell synthesizes RNA and protein in preparation got cell division - as stage comes to an end, cellular metabolic activity slows

Answer 58

- last 6 hours - time of DNA replication - metabolic and growth activities to a minimum - shorter chromosomes are replicated first - protein portion is also duplicated - by end of S phase, each chromosome homologue has doubled but is held together by a single centromere

Answer 59

- relatively short, 4-5 hours - second period of growth - DNA can function again to maximum in preparation for cell division By end of G2 phase, proteins have been constructed and both the DNA and RNA are doubled. Centrioles ave divided, forming a pair of new centrioles at right angles to each other.

Answer 60

1) replicated strands of chromatin become tightly coiled 2) the identical halves, chromatids, are joined at the centromere 3) the nucleolus and nuclear envelope disintegrates, the fragments scattering in the cytoplasm 4) the centrioles (composed of microtubules) separate and migrate to the opposite poles of the cell. 5) microtubules aggregate to form mitotic spindle that is attached to centrioles

Answer 61

1) identical sister chromatids move to the center of the spindle 2) each chromatid pair is attached to a spindle fiber and aligned along the equator of the cell. 3) point of attachment is the centromere

Answer 62

- begins as soon as chromatids pull apart and lasts until newly formed chromosomes reach the opposite poles of the spindle - chromatid pains are separated, with one half of each pair being pulled at their centromere by the spindle fibers toward each pole.

Answer 63

1) the chromosomes arrive at opposite poles of the cell early in phase. One of each kind of chromosomes arrives at each of the poles of the cell. 2) the nucleolus and nuclear membrane reappear and spindle fibers disappear during this phase 3) because the chromosomes uncoil and become lo nger and thinner, the chromosome structural formation disappears 4) the DNA and proteins (nucleoproteins) now assume their distinctive chromatin arrangement

Answer 64

Division of cytoplasm

Answer 65

- follows telophase 1) cytoplasm around the two new nuclei becomes furrowed and the cytoplasmic membrane pinches in. 2) pinching in is accomplished by the contraction of a ring of microfilaments that forms at the furrow. 3) at completion, two new and identical daughter cells have been formed

Answer 66

Some cells continue through the mitotic cycle repeatedly, but others lose their mitotic ability and enter a protracted state of mitotic inactivity

Answer 67

Cell death

Answer 68

- Active (programmed cell death and necrosis) - passive (cell death without known regulatory mechanisms

Answer 69

- chromatin condensation and fragmentation - cell shrinkage - elimination of dead cells by phagocytosis

Answer 70

Usually occurs by apoptosis

Answer 71

Results from acute cellular injury, which produces rapid cell swelling and lysis

Answer 72

With specific growth factor: - one mechanism is increased synthesis of anti-apoptotic proteins

Answer 73

Activation of intracellular proteases, known as caspases.

Answer 74

- intrinsic - extrinsic

Answer 75

- focuses on mitochondria as initiators of cell death

Answer 76

Relies on TNF family death receptors for triggering apoptosis

Answer 77

- leukemias —> chronic lymphocytic leukemia —> SLE —> follicular lymphomas —> cancers with p53 mutations

Answer 78

- AIDS - aplastic anemia

Answer 79

Ova or sperm

Answer 80

- Sister chromatids lining up end to end - allows for easy exchange of genetic material through crossing over.

Answer 81

The study of the entire genome of an organism

Answer 82

The study of actual gene expression or gene profile of a specific cell at an exact gene expression or gene profile of a specific cell at an exact stage of cellular differentiation or functional activity

Answer 83

- the study of the composition, structure, function, and interaction of proteins produced by a cell

Answer 84

- the specfic genetic makeup of an individual, usually in the form of DNA. it codes for the phenotype of that individual.

Answer 85

- an individual organisms EXPRESSED total physical appearance and constitution or a specific manifestation of a trait, such as a size or eye color, that varies between individuals

Answer 86

- by genotype, or by the identity of the alleles that an individual carries at one or more positions on the chromosomes - by multiple genes and influenced by environmental factors

Answer 87

- refers to allele that causes a phenotype that is seen in a heterozygous genotype (ex: brown eye color = Bb) - a person only needs to inherit one copy of the gene for the trait to be expressed

Answer 88

- an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (ex. Blue eye color = bb) - a person must inherit two copies of this gene for the trait to be expressed - thus both parents have to carriers of the recessive trait in order for a child to express that trait - if both parents are carriers, there is a 25% chance with each child to show the recessive trait

Answer 89

- A segment of DNA that is arranged along the chromosome at a specific position called a locus - the functional unit of a chromosome - responsible for determining the structure of a single protein or polypeptide.

Answer 90

- Genes at specific locus that differ in nucleotide sequence

Answer 91

Coding sequences

Answer 92

Intervening sequences

Answer 93

- the change in the DNA sequence that does not result in a functional abnormality

Answer 94

A region of DNA that differs in only a single DNA nucleotide

Answer 95

- hemoglobin S has a difference in one amino acid on the beta Chain. - individuals heterozygous for this trait

Answer 96

A substitution of lysine for glutamic acid in beta chain occurs

Answer 97

Electrophoresis Chromatography

Answer 98

- genetic alteration that causes cancers including leukemias and lymphomas, along with tumor suppressor genes and microRNA genes in affected cells. - usually somatic cell events but germ-line mutations can predispose a person to inherited or familial cancer - ex: Burkitt’s lymphoma

Answer 99

- viral oncogenes have normal counterparts in human genome - ID of these established the fact that the human genome carries gene with the potential to dramatically alter cell growth and to cause malignancy when altered or activated to an oncogene

Answer 100

1) growth factors 2) growth factor receptors 3) signal transducers 4) transcription factors

Answer 101

- mutations - gene rearrangement or gene amplification

Answer 102

When a normal hematopoietic precursor cell, stem cell or more differentiated progenitor cell, acquires a cancer-inducing mutation

Answer 103

- specific tumor suppressing genes (p53 genes) inhibit cell growth in normal cells - transcription factor encoded by TP53 gene - guardian of the genome because it conserves stability by preventing genome mutations

Answer 104

- acute myeloid leukemia - chronic lymphocytic leukemia - chronic myelogenous leukemia - myelodysplastic syndrome - non-Hodgkin’s lymphoma

Answer 105

- low level of disease cells - molecular techniques are more sensitive to low number of cells. Can permit for early detection which means earlier intervention

Answer 106

- deprivation of survival factors such as growth factor or loss of extra cellular matrix - signals from death cytokines such as TNF - cell damaging stress

Answer 107

- toxins - massive injury - severe hypoxia

Answer 108

Conditions of ATP depletion

Answer 109

Enlarged due to swelling

Answer 110

Reduced by shrinkage

Answer 111

Intact but lost phospholipid asymmetry

Answer 112

Disrupted with the loss of integrity

Answer 113

- smallest organized units of living tissues, have the ability to individually perform all the functions essential for life processes

Answer 114

- Process of blood cell production, differentiation and development

Answer 115

- bone marrow - liver - spleen - lymph nodes - thymus

Answer 116

Also takes place in yolk sac, aorta-gonad-mesopnephrons (AGM) regions fetal liver and bone marrow

Answer 117

1) Totipotential stem cells 2) Pluripotential stem cells 3) multipotential stem cells

Answer 118

- present in the first few hours after ovum is fertilized - most versatile type of stem cell - can develop into any human cell type, including development from embryo into fetus

Answer 119

- present several days after fertilization - can develop into any cell type, except they cannot develop into a fetus

Answer 120

- derived from pluripotential stem cells - can be found in adults but are limited to specific types of cells to form tissues. For example, bone marrow stem cells can produce all types of blood cells, bone cartilage and adipose cells

Answer 121

1) embryonic phase 2) fetal hepatic phase 3) medullary ( or myeloid) phase

Answer 122

- primitive hematopoiesis takes place in the yolk sac in the blood islands - begins day ~19 post conception and continues until week 8 of gestation - cells produced: erythrocytes, macrophages, and platelets - erythrocytes contain Gower and Portland hemoglobin Sites: from the yolk-sac to the hepatic (liver) phase to the bone marrow

Answer 123

- begins at 5-7 weeks post conception and continues until approximately 24 weeks of gestation (6th month) —> peak hematopoiesis is ~3 months of gestation - cluster of erythroblasts, granulocytes, and monocytes colonize the fetal liver to eventually mobilize to the bone marrow - microenvironment conducive to hematopoiesis is created by different cell populations that produce cytokines and chemoattractants to the liver - spleen, thymus, and lymph nodes contribute to hematopoiesis during this phase

Answer 124

- bones are large enough to have marrow cavities - 5th month, the bone marrow takes on its role and the chief organ of hematopoiesis in the adult with the liver and spleen acting as supplementary organs of hematopoiesis (EPO), granulocyte colony-stimulating factor (G-CSF), and granulocyte-monocyte colony-stimulating factor (GM-CSF) are present - M:E ratio is 3:1 at this stage - hemoglobin F and Hemoglobin A are present at this stage

Answer 125

- begins 1-2 days later than primitive hematopoiesis - process starts with with the formation of self-renewing HSCs in AGM

Answer 126

HSCs have the ability to proliferate without differentiation

Answer 127

1) the anatomic structure consists of different tissue types and component cells 2) the stroma consists of various cells and extracellular macromolecules that occupy the hematopoietic tissue with hematopoietic cells. Stroma is the microenvironment where hematopoietic progenitor cells (HPCs) grow and differentiate 3) The HPCs are the HSCs and their offspring that become blood cells of multiple specific lineages

Answer 128

- adipose tissue - inactive - replaces red bone marrow in many bones

Answer 129

- cellular - active - active production of of most type of leukocytes, erythrocytes, and thrombocytes - in children, red bone marrow is located throughout the skeletal system - activity occurs in central portion of skeleton

Answer 130

- hematopoietic cells - fat tissue - osteoblasts - osteoclasts - stroma

Answer 131

- erythroid - myeloid - lymphoid - megakarocyte - marrow stromal cells - mast cells - macrophages - bone cells

Answer 132

Enlargement of the spleen and liver

Answer 133

- found within central cavities of axial and long bones. It consists of hematopoietic tissue islands and adipose cells surrounded by vascular sinuses interspersed with a meshwork of trabecular bone, -

Answer 134

- takes place in marrow consisting of stromal cells and extracellular matrix - must be supported by microenvironment that is able to to recognize and retain hematopoietic stem cells and provide factors required to support proliferation, differentiation, and maturation of stem cells along committed lineages - stimulated by erythropoietin

Answer 135

- adventitial reticular cells - endothelial cells - macrophages - adipocytes - bone lining cells (osteoblasts) - elements of the extracellular matrix

Answer 136

- occurs in distinct anatomical sites called erythropoietin islands, specialized niches in which erythroid precursors proliferate, differentiate, and enucleate - each island consists of an iron-laden macrophage surrounded by a cluster of erytrhoblasts - within each island, cell-cell and cell-extracellular matrix adhesion, positive and negative regulatory feedback, and central macrophage function occur

Answer 137

- myeloid cells account for 23-85% of the nucleated cells in normal bone marrow - early cells are located in the cords and around bone trabeculae - neutrophils in the BM reside in the proliferating pool and the maturation storage pool - need 3 to 6 days in the proliferating pool to mature - if needed, the cells from the storage pool can enter peripheral circulation and have life span of 6-10 hours

Answer 138

- take places adjacent to the sinus endothelium - protrude through the vascular wall as small cytoplasmic processes to deliver platelets into blood - take approximately 5 days to develop

Answer 139

- kidney - minor amounts from liver

Answer 140

- according to maturity 1) primitive - multipotential cells. The most immature group of capable of self-renewal and differentiation into all blood cell lines 2) intermediate cells (committed progenitors). This group consists of committed progenitor cells destined to develop into distinct cell lines 3) precursors: give rise to mature cells; morphologically distinguishable in bone marrow and peripheral circulation 4) mature cells. The most developed group with specific physiologic functions

Answer 141

- exists in the bone marrow in a highly organized, 3-D microenvironment composed of an diverse population of stromal cells and extracellular matrix rich in fibronectin, collagens, and various proteoglycans

Answer 142

1) G-CSF (granulocyte - colony stimulating factors) 2) GM-CSF (granulocyte-macrophage colony stimulating factors) 3) M-CSF (monocyte colony stimulating factors) 4) erythropoietin 5) IL-3

Answer 143

- unlike other cell lines, lymphocytes and plasma cells are produced in lymphoid follicles - plasma cells are located along the vascular wall - lymphoid cells typically account for 1-5% of the nucleated cells in the normal BM

Answer 144

The meshwork of stromal cells is composed of reticulum cells, histiocytes, adipose cells, and endothelial cells

Answer 145

- tissue mast cells, a connective tissue cell of mesenchymal origin, are normally observed in bone marrow - form from HPCs in response to stem cell factor (KIT ligand, which is ligand for CD117) - major effector cells of allergic reactions that are activated by exposure to antigen that cross-links allergen-specific IgE - contain heparin, histamine, serotonin and proteolytic enzymes.

Answer 146

Also called reticulum cells or histiocytes, appear as large cells in the bone marrow - these cells constitute a physiological system, mononuclear phagocyte system - macrophages and monocytes migrate freely into the tissues from the blood to replenish and reinforce the macrophage population - most important step in the maturation of macrophages is cytokine-driven conversion of the normal resting macrophages to the activated macrophages. - can be activated by IFN-gamma and G-CSF

Answer 147

- osteoblasts are bone-matrix-synthesizing cells that resemble plasma cells and are usually observed in groups

Answer 148

- populated by primitive lymphoid cells from the yolk sac and liver. - lymphoid cells physically push the epithelial cells apart - T-cell progenitors migrate to the thymus from the bone marrow for further differentiation - CD34+ progenitor cells develop in the thymic cortex - lymphocytes in the thymus = thymocytes - lymphocyte precursors differentiation is under influence of thymosin - also regulates immune function by secretion of multiple soluble hormones

Answer 149

- characterized by a blood supply system; unique because it only consists of capillaries. - function is to act as a densely populated “waiting zone” of progenitor T cells - before cells enter the cortex,the lack CD4 and CD8 surface markers. As they get closer to the medulla, the cells will progress to mature T cells that express their CD4 and CD8

Answer 150

- Proteins produced by many different type of cells - bind to their receptors on the surface of a target cell - induce intracellular signaling to the target cell for survival, proliferation, or differentiation responses to initiate a signaling pathway - includes: interleukins, colony-stimulating factors, and interferons

Answer 151

- lymph nodes - spleen - gut-associated lymphoid tissue (GALT) - thoracic duct - bronchus-associated lymphoid tissue (BALT) - skin-associated lymphoid tissue and blood, - lymphocytes circulate in the peripheral blood and lymphatic tissues and through secondary lymphoid organs

Answer 152

- highly vascular - major function of removing aging and damaged blood cells and particles, such as antigen-antibody complexes and opsonized microbes from the circulation and initiate adaptive (antibody) immune response to blood-borne antigens - also stores platelets and participates in immune defense. About 1/3 of body pool of platelets are here - contains largest amount of lymphocytes and macrophages int he body - has red pulp, white pulp, and the marginal zone - only lymphoid organ that has majority B lymphocytes instead of T lymphocytes

Answer 153

- sinusoids of the red pulp are lined by discontinuous epithelium, allowing passage of cells between the cords and the sinuses - sinuses lined with macrophages which create filter that blood can seep through - these sinuses trap red cell inclusions, older RBCs (older than 120 days) for recycling, and platelets - the reservoir for platelets

Answer 154

- The spleens ability to pluck out particles from intact erythrocytes without destroying them. - blood cells coated with antibody are susceptible to pitting by splenic macrophages - reduces the surface to volume ratio and results in formation of abnormally shaped spherocytes

Answer 155

- initiating immune reactions involving both cellular and humoral immunity - lymphoid cells form a cylindrical cuff around splenic arterioles, and these are mainly T cells.

Answer 156

- also called hypersplenism - enlargement of the overall size of the spleen. Causes some degree of extreme reduction of erythrocytes, leukocytes, and platelets in circulating blood - can result in pooling of 80-90% of platelets and produces peripheral blood thrombocytopenia

Answer 157

- thrombocytopenia - Gauchers’s disorder (macrophage accumulate large quantities of indigestible substances) - Neoplasm (malignant cells occupy much of the splenic volume - hepatosplenomegaly - tumor cells - will show hypersplenism which is complication of sickle cell anemia —> functional splenectomy or autosplenectomy

Answer 158

- located all along the lymphatic vessels, and lymph fluid circulates through the nodes as it progresses through the lymphatic system - lymphocytes circulate between the blood, organs and lymphatic tissues

Answer 159

1) sites of lymphocyte proliferation in the germinal center 2) filter particulate matter, bacteria, or debris that enters the node via the lymph 3) participate in the immune response to foreign antigens

Answer 160

Able to function in the immune response

Answer 161

- Adenitis ( increased number of microorganisms flow through the lymph nodes and overwhelm macrophages and infection of node can start - lymphadenopathy (enlargement of lymph nodes) - cancel cells can break lose and enter the lymph nodes. Malignant ones have potential of growing and metastasizing to other nearby nodes

Answer 162

- immunologic tissue effector - most frequent sampled lymphoid organ

Answer 163

- each HSC or progenitor cell has the unlimited and equivalent capacity to differentiate into many potential progeny, and specific signals from the cells environment determine the pathway of an individual cell.

Answer 164

Supports the proposition that the cellular environment makes no difference

Answer 165

- foundation of two major ancestral cell lines: lymphocytic (lymphoid) and nonlymphocytic (myeloid) cells

Answer 166

- precursor of either mature T cells or B cells/plasma cells

Answer 167

- progresses to the progenitor colony-forming unit, granulocyte-erythrocyte-monocyte-megakaryocyte (CFU-GEMM)

Answer 168

- a prefix to record the number of colony-forming units of different progenitor cells that are identified through in vitro clonal assays

Answer 169

- CFU-granulocyte-macrophage/monocyte (CFU-GM) - CFU-eosinophil (CFU-Eo) - CFU-basophil (CFU-B) - CFU-megakaryocyte (CFU-Meg) - in erythropoiesis, differentiates into the burst forming unit, erythroid (BFU-E)

Answer 170

- chronic lymphoproliferative disorders - chronic infections

Answer 171

- includes promonocytes and their precursors in bone marrow, monocytes in circulating blood, and macrophages in tissues - functions: rapid phagocytosis mediated by receptors for IgG and the major fragment of C3 - macrophages, network of reticular cells of the spleen, thymus, and other lymphoid tissues are organized into this system

Answer 172

- cellular source: Peritubular cells of kidney, and Kupffer’s cells - progenitor cell target: CFU-E, late BFU-E and CFU-Meg - mature cell target: none - gene located on chromosome 7

Answer 173

- cellular source: activated T cells - progenitor cells Target: CFU blast, CFU-GEMM, CFU-GM, CFU-G, CFU-M, CFU-Eo, CFU-Meg, CFU-Baso, BFU-E - mature cell target: eosinophils and monocytes

Answer 174

- cellular source: monocytes, fibroblasts, endothelial cells - progenitor cell target: CFU-G - mature cell target: granulocytes - located on chromosome 17

Answer 175

- cellular source: monocytes, fibroblasts, endothelial cells -progenitor cell target: CFU-M - mature cell target: monocytes

Answer 176

- cellular source: T-lymphocytes, monocytes, eosinophils, monocytes, fibroblasts, endothelial cells - progenitor cell target: CFU-blast, CFU-GEMM, CFU-GM, CFU-G, CFU-M, CFU-Eo, CFU-Meg, and BFU-E - Mature cell target

Answer 177

- major role is regulating the proliferation and differentiation of HPCs as well as regulating the survival and function of the mature blood cells.

Answer 178

Myeloid cells

Answer 179

VCAMs receptors

Answer 180

- examination of both bone marrow smears and histologically tissue sections - it is also important to evaluate morphology in both bone marrow and peripheral blood

Answer 181

- formed elements: 45% —> RBC- erythrocytes —> WBC - leukocytes —> platelets - thrombocytes - liquid portion: 55% —> plasma - liquid portion of unclotted blood - contains fibrinogen —> serum - liquid portion of clotted blood - contains no fibrinogen

Answer 182

- the ID and stage of maturation of stained blood can be guided by a variety of systemic features - two important characteristics to observe initially in cell ID are as follows: overall cell size and nuclear-cytoplasmic ratio

Answer 183

- the amount of space occupied by the nucleus in the relationship to the space occupied by the cytoplasm - size of nucleus general decreases as the cell matures

Answer 184

- play an important role in cell ID. Important features of the nucleus include the following: —> chromatin pattern —> nuclear shape —> the presence of nucleoli

Answer 185

- lymphocytes exhibit a smooth or homogenous pattern of chromatin throughout development until the mature stage, when clumped heterochromatin is more obvious - granulocytes progress from having a fine to a highly clumped pattern - monocytes have a lacy pattern, which becomes finer as the cell matures. - erythrocytes continue too develop a more clumped pater as maturation progresses, until the extremely dense (pyknotic) nucleus is lost (extruded) from the mature cell.

Answer 186

- lymphocytes usually continue to have a round or oval nucleus. Some cells may have a small cleft in the nucleus - monocytes have a kidney bean-shaped nucleus, but folded or horseshoe shapes are common - mature neutrophils, eosinophils, and basophils have segmented nuclei attached to one another by fine filaments. The number of distinctive lobes ranges from two to five depending on the cell type

Answer 187

- the presence or absence of nucleoli is important in the ID of cells - the three cell lines of erythrocytes, leukocytes, and megakaryocytes all have nucleoli in the earliest cell stages - as cells mature, nucleoli are usually not visible. These changes in the appearance of the nucleoli are related to the rate of synthesis of ribosomal RNA

Answer 188

1-2 but occasionally 3-4

Answer 189

0-2, may stain darker than other blast cells

Answer 190

- staining color and intensity - granulation - shape - quantity of cytoplasm - vacuolization - inclusion bodies

Answer 191

- variation among stages of maturation: younger cells tend to be more blue, whereas more mature cells are more pink to neutral colored

Answer 192

- identify both the presence and granule to identify the cell

Answer 193

- blasts, monocytes, and megakaryocytes are most distinctive

Answer 194

- in some cell types, such as megakaryocytes, the quantity of cytoplasm increases with age

Answer 195

- vacuoles can be seen in monocytes at a normal finding - in other cell types, however, they are a sign of increasing age or abnormal conditions

Answer 196

- examples include Auer rods, which can aid in the ID of the cell that it contains it

Answer 197

- HSC - myeloid progenitor cell - myeloblasts - myelocyte - basophilic metamyelocyte - basophilic band cell (released from marrow) - basophil - Function: allergic reaction

Answer 198

- HSC - myeloid progenitor cell - myeloblast - myelocyte - eosinophilic metamyelocyte - eosinophilic band cell (released from marrow) - eosinophil - Function: allergic reactions and anti parasitic reactions

Answer 199

1. myeloblast 2. Promyelocyte 3. myelocyte 4. Metamyelocyte 5. Band 6. Neutrophil - Function: Phagocytosis and acute inflammation

Answer 200

- HSC - myeloid progenitor cell - megakaryoblast - promegakaryocyte - megakaryocyte - platelets (or thrombocytes) - Function: coagulation

Answer 201

1. Rubriblasts 2. Prorubricytes 3. Rubricytes 4. Metarubricytes 5. Reticulocyte 6. Mature erythrocyte

Answer 202

- HSC - myeloid progenitor cell - monoblast - promonocyte - monocyte - Function: phagocytosis, and antigen capture

Answer 203

- HSC - lymphoid progenitor cell - pre-B cell - bone marrow - either stays B cell or differetiates into plasma cell - both play roles in the humoral immunity

Answer 204

- HSC - lymphoid progenitor cell - pre-T cell - thymus - T cell - plays role in cellular immunity

Answer 205

- eosinophil - neutrophil - basophil

Answer 206

- monocytes - lymphocytes

Answer 207

- Lobulated nuclear shape average - very clumped chromatin - pink cytoplasmic color - many granules - pink granules with a few blues ones - 56%

Answer 208

- curved nuclear shape average - moderately clumped chormatin - blue/pink cytoplasmic color - many granules - pink granules - 3%

Answer 209

- Round nuclear shape average - smooth chromatin - light blue cytoplasmic color - few or absent granules - red granules - 34%

Answer 210

- indented or twisted nuclear shape average - lacy chromatin - gray-blue cytoplasmic color - many granules - dusty blue granules - 4%

Answer 211

- lobulated nuclear shape average - very clumped chromatin - granulated cytoplasmic color - many granules - orange granules -2.7%

Answer 212

- Lobulated nuclear shape average - very clumped chromatin - granulated cytoplasmic color - many granules - dark blue granules - 0.3%

Answer 213

- occurs when the bone marrow becomes dysfunctional in cases such as aplastic anemia, infiltration by malignant cells, over proliferation of cell OR when the bone marrow is unable to meet the demands places on it, as in the hemolytic anemias - sites: spleen, liver, and lymph nodes

Answer 214

Thrombocytes Erythrocytes

Answer 215

- foundation procedure performed in hematology laboratory - consists of quantitative measurements of: —> hemoglobin —> hematocrit —> red and white blood cell counts —> platelet count —> leukocyte differential —> morphological evaluation of a peripheral blood smear

Answer 216

- plasma specimen - lavender top (EDTA) -store at room temp or refrigerated

Answer 217

- hemolyzed - clotted specimen - wrong tube or container - tube note labeled - inadequate quantity - tube mislabeled

Answer 218

- pre-analytical - specimen collection, transport, and processing - analytical - testing - post analytical - testing results transmission, interpretation, follow-up, retesting

Answer 219

- pre- analytical - post analytical

Answer 220

- patient ID - phlebotomist technique - test collection procedures - specimen transport - specimen processing

Answer 221

- test system not calibrated - results reported when control results are out of range - improper measurements of specimens and/or reagents - reagents prepared incorrectly - reagents stored inappropriately or used beyond expiration date - instrument maintenance not done - dilution and pipetting errors - inaccuracy - imprecision errors - insensitivity - linearity issues

Answer 222

- interpretation of results - critical value not called - transcription errors in reporting - report sent to the wrong location - report illegible - report not sent

Answer 223

- erythrocytes, leukocytes, and platelets are measured quantitatively using automated instrumentation. Usually automated but occasionally manual counts may need to be performed due to low counts or quality issues

Answer 224

- quality control strategy - backup method of analysis

Answer 225

- standard part of the CBC, specifically MCV - used to mathematically define cell size and the concentration of hemoglobin within the cell. They are MCV, MCH, and MCHC - can also include: —> reticulocyte information —> Red cell distribution width (RDW) —> Blood cell histograms

Answer 226

Mean corpuscular volume

Answer 227

Mean corpuscular hemoglobin

Answer 228

Mean corpuscular hemoglobin concentration

Answer 229

- Blood specimens are diluted to an exact ratio with specific diluent - cells counted in hemacytometer

Answer 230

Accurately ruled chamber, ruled off in areas of square millimeters

Answer 231

- an iron-containing pigment of RBCs composed of four amino acid chains (alpha, beta, gamma, and delta) that delivers oxygen from the lungs to the tissues of the body - Normal values: —> female = 12-16 g/dL —> male = 14-18 g/dL

Answer 232

- the percentage of RBCs in whole blood - also called the PCV (packed cell volume) - normal values: —> female: 36-45% —> male: 42-50%

Answer 233

- manual and automated determination is most commonly performed using the cyanmethemoglobin method

Answer 234

- modified Drabkin’s reagent that contains potassium cyanide is mixed with blood specimen, incubate to induce lysing, and measured using a spectrophotometer at 540 nm - also called hemiglobincyanide method

Answer 235

Problems with specimen integrity - elevations in HB measurement are seen in lipemic, icteric, or hemolyzed blood samples - elevations in HB measurement are also seen in specimens with high WBC counts or RBCs containing HB S or C

Answer 236

- saline (plasma) replacement for icteric, lipemic or hemolyzed plasma - specimen can be centrifuged and clear supernatant be transferred to a cuvette and measured on a spectrophotometer to address high WBC count interference. - specimens with Hb C or S can be diluted 1:2 with distilled water and run with the result multiplied by the dilution factor

Answer 237

- usually used in automated methods - sample is lysed using the detergent-modified Drabkin’s reagent and light absorbance is measured at 540 nm

Answer 238

- the hematocrit (Hct) or packed cell volume is a macroscopic observation of volume of the packed RBCs in a sample of whole blood, if measured manually - The Hct is the percentage of RBCs in a volume of whole blood. It is expressed as units of percent or as a ration in the SI system - an automated hematocrit result is obtained when multi-parameter instruments are used —> the results are computed from individual MCVs and the red cell count and is not affected by the trapped plasma that is left in the RBC column.

Answer 239

- the heavier particles fall to the bottom of the tube, and the lighter particles settle on top of the heavier cells

Answer 240

Include specimen and technical errors - specimen errors can falsely decrease Hct values due to inadequate filling of EDTA tube, which causes RBC shrinkage - technical errors include overcentrifugation or improper sealing of the test capillary tube - patients with clinical RBC disorders such as macrocyclic or sickle cell anemia produce falsely elevated Hct levels

Answer 241

Evaluating and classifying the various types of anemias according to red cell indices

Answer 242

- used to determine accuracy between Hb, Hct, and RBC counts - the states: —> the microhematocrit be 3x the value of the hemoglobin (+/- 3%) —> the hemoglobin should be 3x the value of the RBC count —> the microhematocrit should be 9x the value of the RBC count - the rule only applies to normocytic normochromic red cells, and discrepant values may be seen in other conditions

Answer 243

- in most cases, the total number of RBCs is closely related to the red cell concentration, but in situations such as severe hemorrhage dehydration, or overhydration, plasma volume or red cell mass or volume must be determined - is injected and the volume distribution is calculated from the degree of dilution of the injected substance over a period of 15-30 minutes - radiolabeled albumin is most commonly used - may also be estimated from red cell volume using radioactive labeled RBCs

Answer 244

- by dilution methods

Answer 245

- quantitative cellular volume heterogeneity reflecting the range of RBC sizes within a sample - useful in early classification of anemia as it first starts to become abnormal earlier in nutritional deficiencies such as iron deficiency anemia - useful in characterizing micro types anemias, allowing to distinguish between iron deficiency anemia and beta thalassemia - RDW can also be helpful in identifying RBC fragmentation

Answer 246

- blood specimens are diluted to an exact ratio with specific diluents and the cells are counted in hemacytometer and accurately ruled chamber in areas of square millimeters - since RBC counts surpass WBC and PLT counts, they need to be eliminated to count WBC and PLT counts accurately - most of the lysing agents use the principle of osmotic pressure; placing an aliquot of blood in a hypotonic solution will cause the cell to lyse

Answer 247

- can be very inaccurate - in analysis of RBCs an isotonic solution is used as diluent from whole blood. - because RBCs greatly exceed WBCs, the error introduced by counting red cells and white cells negligible

Answer 248

(average total of RBCs in 5 squares) X (dilution correction factor) X (volume correction factor) = # of RBCs - the specimen dilution factor is 200 - the volume correction factor is 50 - 5 of 25 squares in the large 1-mm square are counted Example: if the average # of RBCs counted is 400, what is the total RBC count? 400 X 200 X 50 (or 400 X 1000) = 4.0 x 10^12/L

Answer 249

- increased or erratic results may be seen if contaminated diluting fluid, wet or dry pipette, a dirty hemacytometer, or drying of the dilation in the hematocytometer occurs

Answer 250

- dilution = 1:100 - diluent = 0.85% NaCl - Objective = 40x

Answer 251

- dilution = 1:20 - diluent = 3% acetic acid, 1% ammonium oxalate, 1% hydrochloric acid - objective = 10x

Answer 252

- dilution = 1:100 - diluent = 1% ammonium oxalate - objective = 40x

Answer 253

- Men: 41.5–50.4% (0.415–0.504L/L) - Women: 36–45% (0.36–0.45 L/L) - at birth: 51% - age 6-12: 40%

Answer 254

- Men: 4.5–5.9 x 10^6/uL (4.5–5.9 x 10^12/L) - Women: 4.5–5.1 x 10^6/uL (4.5–5.1 x 10^12/L) - at birth: 4.7 x 10^12/L - age 6-12: 4.6 x 10^12/L

Answer 255

- Men: 14.0–18.0 g/dL (145–180 g/L) - Women: 12.0–16.0 g/dL (120-160 g/L) - at birth: 16.5 g/dL - age 6-12: 13.5 g/dL

Answer 256

- Men: 80–96 (fL) - Women: 80–96 (fL) - at birth: 180 fL - age 6-12: 86 fL

Answer 257

- Men: 27.5–33.2 (pg) - Women: 27.5–33.2 (pg) - at birth: 34 pg - age 6-12: 29 pg

Answer 258

- Men: 33.4–35.6% (32–36 g/dL) - Women: 33.4–35.6% (32–36 8/dL)

Answer 259

- expresses the average size or volume of an erythrocyte - useful parameter for classification of anemias based on size - terms associated with MCV evaluation are normocytic, microcytic, and macrocytic

Answer 260

- macrocytic Anemia - pathological megablastic anemias (such as pernicious anemia and folic acid deficiencies

Answer 261

- iron deficiency anemia - heterozygous thalassemias - anemias of chronic inflammation/anemia of chronic disorders

Answer 262

- autoagglutination of red cells can cause falsely elevated MCV values - red clumps are not counted in automated methods which will affect the Hct - severe hyperglycemia can cause osmotic swelling of red cells which leads to falsely elevated levels - leukocytes is may also falsely elevate MCV values

Answer 263

(Patients packed cell volume or Hct (L/L))/Erythrocyte count (x10^12/L)) - example: —> patient Hct = 35% (0.35 L/L) —> erythrocyte count = 4.0 x 10^12/L (0.35 L/L)/(4.0 x 10^12/L) = 8.75 x 10^-15 = 87.5 fL *one femtoliter (fL) = 10^-15 L = 1 cubic micrometer (um^3)

Answer 264

- expresses average weight (content) of hemoglobin per red cell. It is directly proportional to the amount of hemoglobin and the size of the erythrocyte

Answer 265

- in anemia secondary to impaired hemoglobin synthesis, the hemoglobin mass per red cell decreases, resulting in a lower MCH value

Answer 266

- may be falsely elevated by hyperlipidemia As increased plasma turbidity will erroneously elevate hemoglobin measurement

Answer 267

- expresses the average concentration (weight) of hemoglobin per unit volume of erythrocytes in the sample - also defined as the ratio of the weight of hemoglobin to the volume of erythrocytes -reference values: 33-36% (g/dL) - terms associated with MCHC evaluation are normochromic, hypochromic and hyperchromic (which can only be spherocytosis or a problem with the Hgb or Hct values)

Answer 268

(Hemoglobin (x10g/dL))/(erythrocyte count (x10^12/L)) = pg - example —> hemoglobin = 14 g/dL —> erythrocyte count = 4 x 10^12/L (140 g/dL)/(4 x 10^12/L) = 35 x 10^-12 g = 35 pg * one picogram (pg) = 10^-12 g = 1 micromicrogram (uum)

Answer 269

(Hemoglobin (g/dL))/(Hct (L/L)) x 100= g/dL - example —> hemoglobin = 14 g/dL —>Hct = 45% (0.45 L/L) (14 g/dL)/(0.45 L/L) = 31 g/dL

Answer 270

- 50% patients with hereditary spherocytosis demonstrate an elevated MCHC - this make spherocytosis most common condition associated with MCHC - other conditions can elevate MCHC such as lipemia, active cold agglutinin disease

Answer 271

- accuracy is affected by factors that affect measurement of either Hct, such as plasma trapping, or presence of abnormal red cells or hemoglobin such as hyperlipidemia or leukocytosis - autoagglutination at room temperature will falsely elevate MCV and decrease RBC count which results elevated MCHC - falsely elevate hemoglobin concentration - hemolysis

Answer 272

4.5–11.0 x 109/L

Answer 273

- Values above the reference range - can be seen in acute bacterial infections, inflammation, malaria, hemorrhage, pregnancy, some anemias, and in some carcinomas, including leukemia

Answer 274

Values below the reference range

Answer 275

- automated: ACT diff 2 - manual: —> Neubauer hemocytometer * 3mm x 3mm x 0.1mm = 0.9mm^3 —> Fochs-Rosenthal hemocytometer * 4mm x 4mm x 0.2 mm = 3.2 mm^3

Answer 276

- LeukoCount Solution —> Acetic buffer —> Gentian violet

Answer 277

- EDTA whole blood - 1:20 dilution for testing

Answer 278

- read on 10x - read 4 sections (in 4 corners) - count from both sides should be no more than 10 cells

Answer 279

- each “section” has an area of 1 mm^2 and a depth of 0.1mm - volume of 1 “section” : area x depth —> 1 mm^2 x 0.1 mm = 0.1 mm^3 - count 4 “sections for total volume counted of 4 x 0.1 mm^3 = 0.4 mm^3

Answer 280

(Volume desired)/(volume used) (1.0 mm^3)/(0.4 mm^3) = 2.5 * volume desired is always 1 mm^3 * if different # of squares were counted, the correction factor would change. - example: 5 squares counted (1 mm^3)/(0.5 mm^3) = 2.0

Answer 281

Correction factor (CF) x dilution factor (DF) x # of cells counted = WBC count -example: 90 cells counted 20 x 2.5 x 90 (or 50 x 90) = 4.5 x 10^3/mm^3 - report out —> WBC count: 4.5 x 10^3/mm^3 * 50 is the multiplication factor (CF x DF)

Answer 282

- failure to mix blood properly - dilution error - failure to wipe off pipette - failure to mix - failure to discard first drop of dilution - improper charging or chamber - dirty hemocytometer

Answer 283

- all numbers MUST have units - count both sides of hemocytometer and average out counts - count cells ON the left and top lines but not on the bottom and right lines.

Answer 284

- certain viral infections with typhoid fever and malaria - after radiation therapy - classic pernicious anemias - after chemotherapy treatments

Answer 285

- many acute infections, especially bacterial infections - severe malaria - after hemorrhage - during pregnancy - postoperatively - some forms of anemias - in some carcinomas - leukemia

Answer 286

- sepsis - immunosuppressive agents

Answer 287

- absolute cell counts - assessment of eosinophils and basophils - neutrophilic hypersegmentation index - neutrophilic function - leukocyte alkaline phosphatase test - erythrocyte sedimentation rate (ESR)

Answer 288

- the absolute number of segmented neutrophils and bands - less specific for inflammation

Answer 289

- examination of a peripheral blood smear normally demonstrates an average of approximately 4% eosinophils - procedure required only if an extreme increase in eosinophils is demonstrated on a peripheral blood smear

Answer 290

Total leukocyte count x percentage of cell type = absolute cell value = absolute count Example: —> total leukocyte count: 15.0 x 10^9/L —> bands 12%, segmented neutrophils 80% and lymphocytes 8% 15.0 x 10^9/L x 0.80 = 12.0 x 10^9/L segmented neutrophils * this formula can be used to determine the absolute value of any cell appearing on a leukocyte differential blood smear

Answer 291

- counting the number of lobes can be performed to determine the neutrophilic hypersegmentation index (NHI) - a right shift or increase in the number of lobes to five or more occurs in various conditions, being chronic nephritis, pernicious anemia and folic acid diagnosis

Answer 292

1) lobe average: determined by counting the number of lobes in a number of neutrophils. Reference value is 2.5–3.3 2) percentage of neutrophils with five or more lobes. Count the number of lobes in randomly selected segmented neutrophils. Add up the total number of lobes for each segmented neutrophil counted, and divide by the total number of cells counted. Reference range is greater than 3% 3) Hypersegmentation index. (# of neutrophils with 5 or more lobes x 100)/(# of neutrophils with 4 lobes) —> values greater than 16.9 are considered to indicate hypersegmentation —> most sensitive method

Answer 293

- established parameter of inflammation in the modern clinical laboratory - standard method of choice: Westergren method - nonspecific indicator of disease - most commonly performed lab tests

Answer 294

- Male, under age 50 = 10 mm/hour - Female, under age 50 = 13 mm/hour - Male, age 50+ = 13 mm/hour - Female, age 50+ = 20 mm/hour

Answer 295

Erythrocytes with abnormal or irregular shape, such as sickle cells or spherocytes, hinder rouleaux formation - removal or fibrinogen by defibrination

Answer 296

- rouleaux - increased fibrinogen levels - relative increase of plasma globulins caused by loss of plasma albumin - absolute increase of plasma globulins

Answer 297

- increased ESR levels —> anemia —> infections —> inflammation —> tissue necrosis (myocardial infarction) —> pregnancy —> some types of hemolytic anemia

Answer 298

- Male: 4.5–5.9 x 10^6/mm^3 (or uL) - Female: 4.5–.5.1 x 10^6/mm^3 (or uL) - infant: 9.0–30.0 x 10^6/mm3 (or uL)

Answer 299

1) extreme physcial exercise - increases count 2) severe dehydration - increase count 3) Age —> newborn has increased counts —> drops rapidly, reaches lowest point at 2-4 months —> gradually rises to adult levels by 14 years of age —> gradually drops in old age 4) sex 5) altitude —> increased altitude causes increased RBC counts —> hypoxia (lack of O2 cause increased RBC counts

Answer 300

- Elevated RBC counts - three types: —> polycythemia Vera —> secondary polycythemia or absolute —> relative polycythemia

Answer 301

-type of erythrocytosis - is a pathological increase in RBCs and other blood cells

Answer 302

- increase in erythropoietin production - can occur in: —> hypoxia —> certain types of anemia —> chronic lung disease —> inappropriate erythropoietin production —> smokers

Answer 303

- caused by decrease in plasma volume - total RBC mass is not increased it just looks like it due to the loss of plasma volume, dehydration - replace fluid, RBC count is back to normal

Answer 304

Deficiency in the total number of RBCs present in the body - occurs with anemia and leukemia

Answer 305

- automated —> ACT diff 2 - manual —> Neubauer hemocytometer * 3 mm x 3 mm x 0.1 mm = 0.9 mm^3

Answer 306

- Hayem’s (HgCl3 + NaCl + NaSO4 + H20)

Answer 307

- dilution for manual RBC counting is 1:200 - count 5 “R” sections of the 25 sections in the middle portion of the hemocytometer - 1/25 or 0.04 mm^2 - 0.04 mm^2 0.1 mm (depth) = 0.004 mm^3 (this is the volume)

Answer 308

Dilution factor x volume correction factor x cells counted 200 x 50 x # of cells counted = RBC count Example: 400 RBC counted 200 x 50 x 400 (or 10,000 x 400) = 4,000,000

Answer 309

Overlapping RBCs, often referred to as a “stack of coins” caused by abnormal or increase plasma proteins

Answer 310

- Can scale the severity of the erythrocyte abnormalities - semiquantitative

Answer 311

Variation in normal RBC size

Answer 312

Variation in normal RBC shape

Answer 313

0 = normal appearance or slight variation 1+ = only a small population displays a particular abnormality. Terms: “slightly increased” or “few” 2+ = more than occasional numbers of abnormal erythrocytes can be seen in microscope. Terms: “moderately increased” 3+ = severe increase in abnormal erythrocytes in each microscopic field. Terms: “many” 4+ = most severe state of erythrocytic abnormality, with the abnormality prevalent through microscope. Terms: “marked” or “increased marked”

Answer 314

- semi quantitative estimate of WBCs to qualitative measurements of WBC is good quality control step

Answer 315

1) select appropriate area of stained blood smear at 40x magnification 2) count the # of WBCs in each of the ten fields 3) calculate estimate total concentration of WBCs per uL (average # of WBC) x (2,000) 4) compare estimate with the quantitatively determined automated or manual WBC count Example: 8 WBCs per field 8 x 2,000 = 16,000/uL (or mm^3) or 16.0 x 10^9/L

Answer 316

- microscopic examination of PB smear - perform a differential on a blood smear from PB —> wright stain is used to stain smear —> Normally see only more mature forms —> performed systematically using the maturational features

Answer 317

1) start with low power (10x) —> evaluate blood smear quality, color, distribution of cells —> inspection for rouleaux or agglutination can be observed —> large immature abnormal cells or disintegrating lymphocytes and smudge cells can be seen —> platelet clumping or satellism may also be seen. 2) Move to High dry power (40x) —>WBC estimates can be assessed —> oil immersion lens (100x) —> leukocytes differential can be performed here —> RBC morphology can also be graded and evaluated here

Answer 318

1) begin with a correctly prepared and stained smear 2) focus on 10x objective, scan the smear to check for cell distribution, clumping and abnormal cells 3) move to 40x and using the fine adjustment, focus then. —> add a drop of immersion oil and switch to 100x —>find suitable are and begin counting the manual leukocyte differential 4) a total of at least 100 leukocytes should be counted. Express the results as a percentage of total leukocytes counted 5) abnormalities of leukocytes, erythrocytes, and platelets should be noted.

Answer 319

- peripheral blood - bone marrow - body fluid sediments (spinal fluid) *smears should be made within 1 hour of blood collection from EDTA specimens to avoid distortion of cell morphology

Answer 320

- lobulated nucleus - very clumped chromatin - pink cytoplasm - many granules - pink granules with few blue - average percent: 56%

Answer 321

- curved nucleus - moderately clumped chromatin - blue/pink cytoplasmic - many granules - pink granules - average percentage: 3%

Answer 322

- round nucleus - smooth chromatin - light blue cytoplasm - few or absent granules - red granules - average percentage: 34%

Answer 323

- indented or twisted nucleus - lacy chromatin - gray-blue cyroplasm - many granules - busty blue granules - average percentage: 4%

Answer 324

- lobulated nucleus - very clumped chromatin - granulated cytoplasm - many granules - orange granules - average percentage: 2.7%

Answer 325

- lobulated nucleus - very clumped chromatin - granulated cytoplasm - many granules - dark blue granules - average percentage: 0.3%

Answer 326

- smears not made within 1 hour of extraction with EDTA blood specimen - changes due to technical error: alterations of the cellular nucleus, degranulation or cytoplasmic vacuoles

Answer 327

- similar size of lymphocytes - automated analyzer WBC counts can be falsely elevated due to NRBC’s in the sample - When completing a differential if there are more than 10 NRBC/100 WBC’s, a correction of total WBC count must be done

Answer 328

(Uncorrected WBC count x 100)/(100 + # NRBC per 100 WBC differential count)

Answer 329

- when the percentage of band forms and other immature neutrophils like metamyelocyte and myelocyte increases, the condition is sometimes referred to as a left shift - could be an indicator of infection or malignancy - some authorities advocate doing away with the identification of band forms on the differential because of individual variability in cell identification and limited usefulness

Answer 330

When MCV range is less than 80 fL

Answer 331

When MCV range is normal: 80-96 fL

Answer 332

When the range is over 96 fL

Answer 333

When MCHC range falls below 33%

Answer 334

when MCHC is at normal range: 33-36%

Answer 335

When MCHC exceeds 36%

Answer 336

- a method of counting and measuring (the size) of particles (or biological cells) suspended in a fluid - reference method throughout the world for particle size analysis - method based on measuring changes in electrical resistance when a particle (such as a cell) is suspended in an electrolyte solution - several thousand particles per second are individually counted and sized with great accuracy - this method is independent of particle shape, color and density

Answer 337

1) small opening (aperture) between electrodes is the sensing zone through which suspended particles pass. In the sensing zone each particle displaces its own volume of electrolyte 2) as each cell goes through the aperture, it impedes the current and causes a measurable pulse 3) the number of pulses signals the number of particles 4) the height of each pulse is proportional to the volume of that particle 5) the quantity of suspension drawn through the aperture is precisely for an exact reproducible volume

Answer 338

1) electrical impedance 2) optical detection

Answer 339

- referred to as the coulter principle - cell counting and sizing are based on the detection and measurement of changes in electrical impendance (resistance) produced by a particle as it passes through a small aperture - the number of pulses generated during a specific period is proportional to the number of particles or cells, recorded by a scattergram - the amplitude (magnitude) of the electrical pulse produced indicates the cells volume - the output histogram is a display of the distribution of cell volume and frequency

Answer 340

- in the optical or hydrodynamic focusing method of cell count in and cell sizing, laser light is used. - a diluted blood specimen passes in a steady stream through which a beam of laser light is focused - as each cell passes through the sensing zone of the flow cell, it scatters the focused light - scattered light is detected by a photodetector and converted to an electrical pulse - the number of pulses generated is directly proportional to the number of cells passing through the sensing zone in a specific period

Answer 341

- cell structure - shape - reflectivity

Answer 342

- light amplification is generated by stimulated emission of radiation. Three independent processes are operational. These are as follows: 1) diffraction and the bending of light around corners with the use of small angles 2) refraction and the bending of light beach of a change in speed with the use of intermediate angles 3) reflection and light rays ruined back by the surface or an obstruction with the use of large angles

Answer 343

- various angles of light scatter can aid in cellular analysis. These are as follows: 1) forward light scatter 0(degrees) —> this is diffracted light, which relates to the volume of the cell 2) forward low-angle light scatter 2-3(degrees) —> can relate to size or volume 3) forward high angle light scatter 5-15(degrees) —> allows or description of the refractive index of cellular components 4) orthogonal light scatter 90(degrees) —> based on reflection and refraction of internal components, which correlates with internal complexity

Answer 344

- in this newer application, high-voltage electromagnetic current is used to detect cell size, based on the cellular density - The RF pulse is directly proportional to the the nuclear size and density of a cell. RF or conductivity is related to the nuclear: cytoplasmic ratio, nuclear density and cytoplasmic granulation

Answer 345

- the electromagnetic spectrum ranges from long radio waves to short, powerful gamma rays - within this spectrum is a narrow band or visible or white light, which is composed of red, orange, yellow, green, blue and violet light - light amplified by stimulated emission of radiation (laser) light ranges from the ultraviolet and infrared spectrum through all the colors of the rainbow

Answer 346

L —> Light A —> amplified (by) S —> stimulated E —> emission (of) R —> radiation - its emission ranges from ultraviolet to infrared through all the color of the rainbow -in contrast to other diffuse forms of radiation, laser light is: —> concentrated —> almost exclusively of one wavelengths or color —> its parallel waves travel in one direction

Answer 347

- glass-filled tubes of helium and neon lasers - the yttrium - aluminum - garnet (YAG) type - imitation diamond - argon - krypton

Answer 348

— they instantly snap back and shed energy

Answer 349

- shorter wavelength light is used as the excitation light for fluorophores - shorter wavelength light absorbed by an electron of the fluorophores and as a result, this higher energy photon excites the fluorophores - excitation doesn’t last long because fluorophores and as a result, this higher energy photon excites the fluorophore - excitation doesn’t last long because fluorophores natural state is ground state

Answer 350

- energy packets of an emitted visible-light particle - basic unit of all radiation - when photons reaches an atom of the medium, the energy exchange stimulates the emission of another photon in the same wavelength and direction. This process continues until a cascade of growing energy sweeps through the medium - travel the length of the laser and bounce off mirrors. First, a few and eventually countless photons synchronize themselves, until an avalanche of light streaks between the mirrors

Answer 351

Nanometer (nm)

Answer 352

The difference, in nm, between the peak excitation and the peak emission wavelength

Answer 353

- laser light is the most common light source used in flow cytoemeters because of the properties of intensity, stability, and monochromatin - flow cytometry is defined as the simutaneous measurement of multiple physical characteristics of a single cell, as the cell flows in suspension through a measuring device - flow cytometry combines that rapidly classify groups of cells with heterogenous mixtures - principle of flow cytometry is based on the fact that cells are stained in suspension. Flow cytometry has specifically come to denote the use of fluoroscencee measurement, usually with a laser light source - the cellular light scatter patterns can be used to identify cells - both intrinsic and extrinsic properties of cells can be analyzed by flow cytometry

Answer 354

- forward- and right-angle light scatter, which correlate with size and granularity of a cell, respectively. This data output does not require addition of cues or stains for detection

Answer 355

- rely binding of various probes to the cell. The scattered light passes through a variety of filters and lenses and it then measured by photomultiplier tubes, which convert the light signals into electronic signals for computer analysis

Answer 356

- light scattered along the axis of the laser beam is “forward scattering” - light scattered perpendicular to the axis is side scatter” or orthogonal scatter - forward scatter is roughly proportional to cell size; side scatter is roughly proportional to cytoplasmic granularity - granulocyte have a much larger side-scattered light signal that do lymphocytes - data are plotted on histograms - populations of similar cells from secrete and characteristics two-dimensional “clusters” of scatter when the forward and side scatters are plotted against each other

Answer 357

- the amount of light scattered by each cell hit by the laser beam - the intensity of the fluorescence emitted by labeled antibodies bound to antigen on the different types of suspended cells

Answer 358

- degree of instrument sophistication is frequently described by a the number of parameters that the instrument generates

Answer 359

- any numerical value that describes an entire population

Answer 360

A subset of a population

Answer 361

Any numerical value describing a sample

Answer 362

- quantitation of nRBC counts - a channel for enumeration of immature granulocytes (IGs) - Random access CD4 lymphocyte counting - analysis of CD34, CD38, and CD61 cell markers - measurement of reticulocyte hemoglobin - enumeration of hematopoietic progenitor cells (HPCs) - counting of IGs

Answer 363

- are graphic representation of cell frequencies versus sizes - in a homogenous cell population, the curve assumes a symmetrical bell-shaped or Gaussian distribution. A wide or more flattened curve is seen when the standard deviation from the mean is increased - not only do they provide information about erythrocyte, leukocyte, and platelet frequency and their distribution about the mean but also depict the presence of subpopulations - provide a means of comparing he size of a patients cells with normal populations. Shifts in one direction or the other can be of diagnostic importance. The position of the curve on the x-axis reflects cell size. In the coulter system. The size (volume in femtoliters) is represented on the x-axis

Answer 364

- the erythrocyte histogram - quantitative descriptors of erythrocytes - the leukocyte histogram - platelet histograms - derived platelet parameters

Answer 365

- WBC - RBC - hemoglobin - Hct - MCV - MCH - MCHC - platelets

Answer 366

- another quality control method for comparing a patients own leukocytes, hemoglobin, MCV, and platelet values with previous results

Answer 367

- reflects the native size of erythrocytes or any other particles in the erythrocyte size range - In the Coulter system, cells are displayed as small as 24 fL, but only those greater than 36 fL are counted as erythrocytes - the extension of the lower end of the scale from 36 to 24 fL allows for the detection of erythrocyte fragments, leukocyte fragments, and large platelets

Answer 368

- larger: curve to the right (megaloblastic anemias) - smaller: curve to the left (iron deficiency anemias)

Answer 369

- an expression of erythrocyte size is the RDW in the Coulter series. This term refers to variation in erythrocyte size - correlations between the RDW and the MCV exist for various types of anemia

Answer 370

- a parameter that expresses the coefficient of variation of the erythrocyte volume distribution. RDW = (SD)/mean size x 100 Reference range: 11.5-14.5%

Answer 371

High RDW: causes megaloblastic anemia Normal RDW: Aplastic anemia in adults

Answer 372

- RDW high: normocytic anemias - RDW normal: reticulocytosis

Answer 373

High RDW: iron deficiency anemia Normal RDW: heterozygous thalassemias, anemias of chronic inflammation or disorders

Answer 374

- size-referenced leukocyte histograms display the classification of leukocyte according to size following lysis. It does not display the native cell size - the histogram of leukocyte subpopulations reflects the sorting of these cells by their relative size, which is primarily related to their nuclear size - as the leukocyte passes through the aperture in the electrical impedance system, they displace their volume in a conductive fluid, which causes a change in electrical resistance as each cell passes through the aperture - only those greater than 35 fL are counted as leukocytes

Answer 375

- lymphocytes —> left side - mononuclear cells —> middle —> ex. Blasts and other immature cells such as promyelocytes, myelocytes, and monocytes - granulocytes —> right side

Answer 376

- between the lymphocytes and mononuclear cells - between mononuclear cells and granulocytes

Answer 377

- platelet counting and sizing in both the electrical impedance and the optical systems reflect the native cell size - in the electrical impedance method, counting and sizing take place in the RBC aperture - in the optical system, forward light scatter pattern discrimination between erythrocytes and platelets in the flow cell determines the platelet count and frequency distribution

Answer 378

More than one cell passing through the aperture at the same time

Answer 379

- coulter model system yield the additional parameters or MPV and PDW - derived from platelet histograms - allow for a size comparison between a patients specimen and the normal populations. Size comparisons are useful as an indicator of certian disorders

Answer 380

- a measure of the average volume of platelets in a sample. The MPV is analogous to the erythrocytic MCV - it is derived from the same data as the platelet count - in healthy patients, there is an inverse relationship between platelet count and size. For example, the volume increases as the platelet count decreases

Answer 381

Whether a patients MPV is normal.

Answer 382

- decreased: —> aplastic anemia —> megaloblastic anemia —> result of chemotherapy —> hypersplenism - increased: —> thrombocytopenia —> myeloproliferative disorders —> heterozygous thalassemia

Answer 383

Measure of the uniformity of platelet size in a blood specimen - serves as a validity check and monitors false results - normal less than 20%

Answer 384

- aplastic anemias - megaloblastic anemias - in chronic myelogenous leukemia - anti-leukemic chemotherapy

Answer 385

- principle of flow cytometry relies n three distinct steps: 1) cytochemical reactions prepare the blood cells for analysis 2) a cytometer measures specific cell properties 3) algorithms convert these measurements in familiar results for cell classification, cell count, cell size and hemoglobinization - the instruments sampling mechanism divides blood samples into aliquots that are treated in four separate reactions chambers

Answer 386

1) hemoglobin 2) RBCs/platelet 3) peroxidase 4) basophil/lobularity

Answer 387

- the RBC/platelet channel uses a laser-based optical assembly that is shared with the basophil/lobularity channel - the light scattered at low and high angles simutaneously measures RBC volume (size) and optical density (hemoglobin concentration) of each cell - additional parameters obtained from the histogram are cell - additional parameters obtained from the histogram are the MCV and RDW - the platelet histogram is derived from measuresurments made with the high-angle detector

Answer 388

- general properties of flow cytometry - hemtaological applicatons - clinical applicatons of flow cytometry - other cellular applications

Answer 389

- major advances this technology are owing to several factors: 1)the ability to produce monoclonal antibodies resulted in the subsequent development of specific surface markers for various subpopulations of cells 2) the development of new fluorescent probes for DNA, RNA, and other cellular components increased the variety of possible applications at the molecular and cellular levels 3) the expansion of computer applications has improved the instrumentation technology, making it easier to operate and more practical for use in clinical as well as research laboratories

Answer 390

1) automated differentials can be based on a variety of principles 2) these include determination of cell volume by electrical impedance or forward light scatter, cytochemistry, or peroxidase staining, and VCS technology 3) flow cytometry can be applied practically to several techniques in the clinical hematology laboratory

Answer 391

- tungsten light- based optics channel, RBCs are lysed and WBCs are fixed and then stained - thousands of cells are characterized by a combination of their size (scatter) and peroxidase activity (absorbance) - scatter is plotted on the y-axis and absorbance is plotted on the x-axis - used to generate the total WBC count and differential count, except for basophils, MPXI

Answer 392

- the index of the mean peroxidase activity of neutrophils as measured by their stain intensity

Answer 393

- megaloblastic anemia - hyperproliferative granulopoiesis, or reactive states

Answer 394

- the nuclear channel is used to measure the conformation of the nucleus of WBCs. - principle is when WBCs are exposed to a surfactant at a low pH, the membranes and cytoplasm of specific leukocytes, neutrophils, eosinophils, Lymphocytes, and monocytes disintegrate and only the bare nuclei remain - the nuclear channel cytometer distinguished leukocytes by differences in nuclear shape and counts basophils. - this laser-based cytometer measures light scattering at two different angles: —> low (0-5 degrees) measures size —> high (5-15 degrees) responsive to the lobularity of nuclei

Answer 395

- polymorphonuclear neutrophil (PMN) appears on the right and the mononuclear nuclei (MN) appear on the left with a valley between them

Answer 396

PMN:MN - an index of the degree of PMN nuclear segmentation: a low value suggests a left shift

Answer 397

- evaluation of internal cellular organelles and nuclear characteristics can be by: —> 90-degrees laser scatter —> polarizing laser light —> RF - separate measurements can be made of individual measurements of volume, conductivity, and light scatter

Answer 398

- reticulocyte: enumeration of reticulocytes by flow cytometry is more accurate, precise and cost-effective - platelet counts: can provide an estimate of young,reticulated platelets by counting platelets that stain with an RNA dye - Immunophenotyping: monoclonal antibodies, identified by a cluster of designation (CD), are used in most flow cytometry immunophenotyping - hematological malignancy: flow cytometry has become an important tool in the diagnosis and classification of hematologic neoplasia by immunophenotyping. Flow cytometry techniques with bone marrow cells are applicable to DNA cell cycle analysis

Answer 399

- solid organ transplantation - stem cell transplantation - monitoring monoclonal antibody therapy - paroxysmal nocturnal hemoginermia testing - fetal hemoglobin - blood parasites - cell functioning analysis - chromosomal analysis - cell sorting

Answer 400

- CD3: target cell: T cells -CD4: target cell: T cells (helper) and monocytes (dimly expressed) - CD8: target cells: T cells (cytotoxic) and macrophages - CD19: target cells: B cells - CD34: target cell: progenitor (hematopoietic stem cells)

Answer 401

A basic immune screening panel typically consists of detection and quantitation of CD3, CD4, CD8, CD19, and CD16/CD56

Answer 402

- important tool in the diagnosis and classification of hematologic neoplasia by Immunophenotyping - intracellular staining is most often used to aid in the diagnosis of acute leukemias and lymphomas

Answer 403

- the quantitation of T and B cells using monoclonal surface markers can be performed using flow cytometry. - CD4 T cell count is one of the standard measures for diagnosing AIDS and management of HIV

Answer 404

- flow cytometric cross-matching uses fluorochrome-conjugated antihuman IgG to detect the binding of alloantibodies to donor lymphocytes in allogeneic organ transplantation. - CD3 and CD19 coupled with anti-IgG in a three-color assay can distinguish T-cells and B-cells mismatches.

Answer 405

- flow cytometry is widely used to enumerate the CD34-positive implanted stem cells. - in some cases CD45 and nucleic acid stains are also detected.

Answer 406

- essential for measuring the expression of cell surface and intracellular markers of multiple drug resistance (MDR) in cancer patients

Answer 407

- GPI-linked proteins, CD55 and CD59, are examined to determine if a deficiency or absence of these cell markers exists.

Answer 408

- detection of fetal hemoglobin and F cells by flow cytometry is becoming common - assay uses monoclonal antibodies to hemoglobin F. - allows for detection of sickle cell disease, and fetal maternal hemorrhage - also allows for quantitation of fetal hemoglobin

Answer 409

- malarial parasites can be screened - uses a riding orange to erythrocytes, and will detect erythrocytes with DNA (malarial) and will fluoresce

Answer 410

- every event that occurs during the process of lymphocyte activation can be measured by flow cytometry

Answer 411

- flow cytometry can be used for karyotyping analysis. - has 7 peaks that represent different groups of chromosomes

Answer 412

- after quickly making the appropriate measurements, the computer makes the decision to sort or isolate a single cell by applying a charge to the cell just as it leaves the flow cell. - the cell is electrostatically deflected into a test tube.

Answer 413

- this new technology, referred to as automated digital cell morphology, provides an unprecedented level of efficiency and consistency - in its simplest form, automated digital cell morphology is a process where blood cells are automatically located and preclassified into categories of blood cells - method that combines ANNs, image analysis and slide handling

Answer 414

- an information-processing model that stimulates the way the human brain processes information. - emulated the neural structure of the brain which is composed of a lot of neurons that work together to solve specific problems

Answer 415

- virtual microscopy - Instrument: DiffMaster Octavia - processes 8 slides per batch - allows for remote review of a smear and storage of up to 20,000 slides with images in a database

Answer 416

- electromechanical - photo-optical methods - platelet agglutination - platelet aggregation - new automation - suggested screen panels: thrombotic hemostasis panel and a fibrinolytic hemostasis panel

Answer 417

- alpha-2-antiplasmin - plasminogen - plasminogen activator inhibitors - tissue plasminogen activator

Answer 418

- antithrombin - Factor VIII:C - Heparin - Lupus anticoagulant - protein C - protein S and free protein S

Answer 419

- earliest instrument to detect blood clotting - the principle of electromechanical methodology is the measurement of conduction or impedance of an electrical current by the formation of fibrin. - example: semiautomated instrument is the fibrometer - system consists of a 37C heat block, an automatic pipette, and a mechanical mixer and timer block - After the appropriate containers are filled and plasma is added to the substrate to initiate the timing mechanism. - timing mechanism triggers a digital readout time and the probe unit. Probes contain electrodes which created electrical potential between it and the moving electrode. - a detection circuit is activated when a fibrin strand is formed between two electrodes - circuit activation stops time and prevents further movement of electrodes

Answer 420

- activated partial thromboplastin time (APTT) - prothrombin time (PT) - factor assays

Answer 421

- the principle of this measurement is that a change in light transmission measured as optical density (absorbance) versus tome can be used to quantitatively determine the activity of various coagulation stages or factors - red LED light is passed through cuvette where it is altered by fibrin clot formation - light is converted into electrical signal and this amplified signal is converted into digital values - photo-optical clot detection systems can be used for the determination of a wide of variety of assays ( APTT, PT, fibrinogen levels and thrombin time)

Answer 422

- factors VIII, IX, XI, and XII

Answer 423

- factors V, VII, and X

Answer 424

- automatic checking of the optical system - storage of standard and assay curves

Answer 425

- the natural thickening (viscosity) is monitored by the motion (amplitude of an oscillating steel ball in a specially designed cuvette), as a change in form takes place - the final result in accurate and is insensitive to colored plasma, lipemic plasma, bilirubin, or turbid reagents, and it is a reliable measurement for the hemostasis laboratory

Answer 426

- as the resistance that a material has to a change in its form

Answer 427

1) movement of the steel ball is triggered by two activating coils, working alternately to induce and maintain a natural oscillation 2) when the start reagent is added, the detection starts immediately 3) when the ball starts to oscillate left and right, a chronometer (clock) begins to time the clotting of the sample 4) as the ball oscillates left and right, the amplitude or motion is also measured. A peak is formed when the ball is detected in the center of cuvette 5) Amplitude is monitored during the entire clotting process 6) as the clot appears, the viscosity increases and the amplitude decreases 7) based on different algorithms, the chronometer is stopped even in the clot is peak, and/or the ball is still in motion

Answer 428

- the ristocetin cofactor assay measures the ability of a patients plasma to agglutinate formalin-fixed platelets in the presence of ristocetin - the rate of ristocetin- induced agglutination is related to the concentration of von Willebrand factor, and the percent normal activity can be obtained from the standard curve - patient values are determined by comparison to a standard curve, allowing the quantitation of percent ristocetin cofactor activity

Answer 429

- the principle of the test is that platelet-rich plasma is treated with a known aggregating agent - if aggregated, cloudiness or turbidity patterns are determined by photometrically comparing the light transmitted through a suspension of aggregated platelets with that of a suspension of non aggregated platelets using an aggregometer - depending of the agonist, the response may be only primary or both primary and secondary —> primary response: reversible aggregation of platelets —> secondary response: irreversible aggregation of platelets

Answer 430

- The Siemens PFA-11 in an automated system that incorporates a high shear flow system to stimulate the in vivo hemodynamic conditions of platelet adhesion and aggregation as encountered at a vascular lesion - this system evaluates the ability of platelets to occlude an aperture in a biochemically active membrane - results are reported as closure (CT) - assess multiple facets of primary hemostasis, namely adherence, activation, and aggregation