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Histology Fall 2019 > Glossary > Flashcards

Glossary Flashcards

1
Q

absorption

A

tissue is penetrated by, or absorbs, a dye solution and becomes colored without any other chemical change or chemical reaction occurring. An example is the absorption of oil red O or Sudan black B by fat.

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2
Q

achromatic

A

without color or not easily stained. In microscopy, achromatic lenses are corrected for 2 colors, red and blue. This helps produce images free of chromatic aberrations.

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3
Q

acid mucosubstances

A

a term used to include both the acid mucopolysaccharides (connective tissue mucins) and the acidic glycoproteins (epithelial mucins). Most acid mucopolysaccharides contain sialic acid. Acid mucopolysaccharides and acidic glycoproteins do not stain the same with all mucin techniques.

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4
Q

acidophillic

A

a basic (cationic, positively charged) substance that is easily stainable with acid dyes. An example is cell cytoplasm, which is readily stainable with the acid (anionic, negatively charged) dye eosin.

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5
Q

additive

A

a chemical or substance that adds on to, or combines with, another substance, usually improving, strengthening, or altering it. Many fixative molecules add on to tissue proteins, altering and stabilizing them in the process.

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6
Q

adeno-

A

a prefix denoting a relationship to a gland

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7
Q

adenoma

A

a benign tumor of epithelial tissue with glandular origin or characteristics, or both

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8
Q

adenocarcinoma

A

a cancer of epithelial tissue that has a glandular origin

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9
Q

adsorbtion

A

the accumulation of stain by the surface of a tissue component. this phenomenon is influenced by the affinity of oppositely charged ions for each other (electrostatic attraction or bonding)

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10
Q

aldehyde

A

an organic compound containing carbon, oxygen, and hydrogen arranged C=O and C-H

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11
Q

aliphatic hydrocarbon

A

organic chemical compound composed of carbon and hydrogen, in which the carbon atoms are linked in an open chain rather than a ring arrangement. Aliphatic hydrocarbons can be used as clearing agents

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12
Q

amphoteric

A

describes a substance that is capable of acting as either a base or an acid, depending on the pH of the solution

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13
Q

anaplasia

A

dedifferentiation, loss of cellular differentiation, or reversion to a more primitive form

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14
Q

angstrom

A

a unit of length equal to 100 millionths (10^-8) of a centimeter, or 10^-10 meters. This unit has been replaced by nanometer nm as the official unit of measurement. One nanometer is equal to 10A or 10^-9 meters

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15
Q

anion

A

a negatively charged dye or tissue component. Anionic substances are also referred to as acidic, although it has nothing to do with pH.

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16
Q

anisotropism

A

having unlike properties in different directions, or unequal in refracting power

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17
Q

anthracotic pigment

A

an accumulation of carbon from inhaled industrial pollution, cigarette smoke, or coal dust. The pigment is seen most frequently in the lungs or in lymph nodes from that area

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18
Q

antibody

A

commonly known as immunoglobulins, antibodies are proteins that are produced by B lymphocytes in response to antigenic stimulation

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19
Q

antigen

A

any substance that can induce a detectable immune response

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20
Q

antigen enhancement

A

epitopes can be exposed or “unmasked” by either heat or enzymes, thus enhancing the antigen-antibody reactivity

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21
Q

antigenic determinant

A

the area of an antigen that determines the specificity of the antigen-antibody reaction

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22
Q

apochromatic

A

corrected for both spherical and chromatic aberration. Apochromatic microscope objectives have been corrected for 3 colors and other lens aberrations

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23
Q

aqueous

A

a solution prepared in water

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24
Q

argentaffin

A

a reaction in which certain tissue components have the ability to bind or be impregnated with silver ions and then reduce the silver to its visible metallic form

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25
Q

argyrophilic

A

the ability to bind or be impregnated with silver ions: however, a reducing agent is required to reduce the silver to its visible metallic form

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26
Q

aromatic hydrocarbon

A

organic chemical compound composed of carbon and hydrogen, in which the carbons are linked in a ring arrangement. Aromatic hydrocarbons are used as clearing agents.

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27
Q

artifact

A

a structure or substance not normally present but produced by some external force or action. examples are mercury pigment, tissue floaters, knife lines, and air bubbles

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28
Q

autolysis

A

destruction or digestion of tissues and cells by the enzymes normally present in the cells

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29
Q

auxochrome

A

the chemical group present in a dye that causes it to bind to certain tissue elements. This group can develop a charge (+ or -) and thus bind to oppositely charged groups present in the tissue. The amino (NH2) and carboxyl (-COOH) groups are frequently occurring auxochromes

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30
Q

axon

A

the nerve process that conducts impulses away from the cell body of the neuron. Neurons have a single axon. Axons are included along with dendrites in the term “nerve fibers”; axons have also been referred to as the axis cylinder

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31
Q

bacilli (singular bacillus)

A

rod shaped bacteria

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32
Q

bacteria (singular bacterium)

A

single cell microorganisms

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33
Q

barcode

A

an optical machine representation of data related to the object to which it is attached. Linear, or one dimensional, barcodes represent data by a series of parallel lines of varying width and spaces. 2-dimensional (2D) barcodes use dots, hexagons, and other geometric patterns to represent data

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34
Q

basophilic

A

an acidic (anionic, negatively charged) substance that is easily stainable with basic (cationic, positively charged) dyes

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35
Q

bevel angle

A

the angle made when the 2 cutting facets of a microtome knife intersect. On most American-made knives, the bevel angel is 28 to 32 degrees

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36
Q

binocular

A

having 2 oculars. a binocular microscope has two eyepieces or oculars

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37
Q

birefringence

A

splitting of a light wave into 2 waves that are refracted in different directions. this phenomenon is also referred to as anisotropsism or double refraction

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38
Q

buffer

A

a solution containing acid and alkaline components in the desired concentration so that the pH will be maintained when small amounts of acids or bases are added

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39
Q

carbohydrate

A

compounds containing, carbon, hydrogen, and oxygen only. Included are sugars, starches, and cellulose.

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40
Q

carcinoma

A

a malignant new growth arising from epithelial tissue

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41
Q

catalyze

A

to modify, speed up, or slow down a reaction without being consumed in the process. Enzymes catalyze biological reactions

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42
Q

cation

A

a positively charged dye or tissue component. Cationic substances are also referred to as basic

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43
Q

chelation

A

forming a ring compound by joining a chelating agent to a metal ion. Chelating agents are organic compounds. An example is ethylenediaminetetraacetic acid EDTA, which decalcifies by binding calcium ions

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44
Q

chromatic aberrations

A

the distortion of color in an image produced by a microscopic lens

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45
Q

chromatin

A

the stainable material (a complex of nucleic acids and protein) in the nucleus.

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46
Q

dispersed chromatin (euchromatin)

A

DNA that is active in RNA synthesis

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47
Q

condensed chromatin (heterochromatin)

A

DNA that is not active in RNA synthesis. Hematoxylin stains only heterochromatin

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48
Q

chromagen

A

a benzene derivative containing a color-bearing group, or chromophore

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49
Q

chromophore

A

the chemical grouping that bestows the property of color on a compound

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50
Q

cirrhosis

A

diffuse fibrosis or sclerosis of any organ, especially the liver

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51
Q

clearance angle

A

the angle formed by the intersection of the block face and the adjacent cutting facet of the knife. This angle should be ~3-8 degrees

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52
Q

clearing

A

process of replacing the alcohol (dehydrating agent) with a reagent that is miscible with paraffin. Most clearing agents leave the tissue transparent, hence the name clearing agent

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53
Q

clone

A

a group of cells that are all derived from a single progenitor cell, all having the same characteristics as one another

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54
Q

coagulation

A

cloudiness, flocculation, and clot formation are stages of grades in the process of coagulation Several reagents coagulate protein sols during the process of fixation

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55
Q

flocculation

A

In colloid chemistry, flocculation refers to the process by which fine particulates are caused to clump together into a floc. The floc may then float to the top of the liquid (creaming), settle to the bottom of the liquid (sedimentation), or be readily filtered from the liquid.

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56
Q

cocci (singular coccus)

A

spherical or spheroid bacteria

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57
Q

decalcification

A

the process of removing calcium from bone or tissue, thus allowing routine microtomy on paraffin embedded material

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58
Q

decolorization

A

the removal of color, or excess color, from tissue. Only some tissue components are decolorized in a process known as regressive staining. Common decolorization methods involve the use of acidic or basic solutions, excess mordant (typically an inorganic oxide, that combines with a dye or stain and thereby fixes it), or oxidizers

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59
Q

dehydration

A

the removal of water from tissue. This is usually accomplished using alcohols

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60
Q

denaturation

A

to change the nature of. fixatives denature proteins by changing the soluble (liquid) contents of the cell into insoluble substances so that those substances are not lost during the subsequent processing steps. This change can be caused by either chemical (fixative solutions) or physical (heat, desiccation) means. Denaturation causes the protein molecule to unfold and the internal bonds to become disrupted

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61
Q

denatured alcohol

A

ethyl alcohol containing another reagent that has been added to make the alcohol undrinkable. Frequently methyl or isopropyl alcohol are used to denature ethyl alcohol

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62
Q

differentiation

A

excess stain is removed from a tissue section, so that only the desired element is left stained and may be visualized easily against the colorless or counterstained background

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63
Q

endogenous

A

pigments or minerals that arise or are produced from within the body

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64
Q

enzyme digestion

A

the use of enzymes to digest certain tissue components. examples are the use of diastase to remove glycogen, or hyaluronidase to remove some types of connective tissue mucin

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65
Q

enzymes

A

proteins that catalyze chemical reactions in biological systems

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66
Q

epithelium

A

a layer of cells that covers or lines all the free, open surfaces of the body including the skin and mucus membranes that communicate with the outside

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67
Q

epitope

A

the simplest form of antigenic determinant present on a complete antigenic molecule

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68
Q

esterases

A

hydrolytic enzymes that act on carboxylic acid esters of alcohols, phenols, and naphthols

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69
Q

exogenous

A

pigments or minerals that originate from outside the body

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70
Q

Fire triangle

A

fuel, oxygen, and an ignition source form what is known as the fire triangle. all 3 of these elements are necessary for a fire

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71
Q

fixation

A

the stabilization of protein

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72
Q

fixative

A

a chemical that alters tissue by stabilizing protein in such a way that the tissue is resistant to further changes

73
Q

flash point

A

the lowest temperature at which a liquid produces enough vapors near the surface of the liquid or within the container used to form an ignitable mixture with air

74
Q

fungi (singular fungus)

A

primitive plants that possess no roots, stems, leaves, or chlorophyll

75
Q

glia (neuroglia)

A

cells that provide the supporting network for the central nervous system. There are 4 types of glial cells: oligodendroglia, astroglia, microglia, and ependymal cells

76
Q

gliosis

A

a condition marked by excessive proliferation of glial cells and or processes

77
Q

glycogen

A

the chief storage polysaccharide in animals. It is especially abundant in muscle and liver tissue. Glycogen is readily hydrolyzed by a- and B-amylase to form glucose and maltose

78
Q

Health information system

A

an electric system that captures a patients health information and documents their visits or encounters throughout a health system

79
Q

hematein

A

the oxidation product of hematoxylin and the active staining ingredient in hematoxylin solutions. Hematein is the active dye formed by the action of either light and air or a chemical oxidizing agent on hematoxylin

80
Q

hematin

A

granular, brownish black crystalline deposit occurring in tissue. Hematin typically denotes formalin pigment, formed by the action of acidic formaldehyde on blood rich tissue, but malarial pigment and acid hematin are also hematins

81
Q

hematogenous

A

pigments derived from blood

82
Q

hematoidin

A

a yellow-brown, crystalline, bile related pigment, probably a heme breakdown product. It is found primarily within old hemorrhagic foci and frequently within old splenic infarcts. It is demonstrated by the techniques for bile.

83
Q

hemochromatosis

A

disease characterized by excessive deposition of hemosiderin in tissues, often interfering with the function of the organs of deposition

84
Q

hemofuscin

A

a brown pigment derived from hemoglobin

85
Q

hemosiderin

A

a loose complex of ferric iron Fe3+ and protein; hemosiderin is the storage form of iron. It is a yellowish brown pigment and is stored primarily in the bone marrow

86
Q

histology

A

the study of the microscopic anatomy of cells and tissue

87
Q

hydrolases

A

enzymes that act on various substrates by either adding or removing water

88
Q

hydroxyapatite

A

a major and essential ingredient of normal bones and teeth. hydroxyapatite makes up bone mineral and the matrix of teeth, and gives bone and teeth their rigidity

89
Q

hyphae (singular hypha)

A

vegetative, tubular fungal structures that may or may not possess cross walls (septa). Many hyphae together compose a matlike fungal colony known as the mycelium

90
Q

hypo

A

a term used to refer to sodium thiosulfate

91
Q

hypotonic

A

a solution that will cause cells to swell. sodium chloride solutions of less than 0.9% concentration are hypotonic to animal tissue cells

92
Q

immunogen

A

an antigen or a substance that can induce an immune response

93
Q

impregnation

A

the deposition of silver or gold on or around, but not in, the tissue component to be demonstrated

94
Q

incubation

A

to maintain sections at optimal environmental conditions for the desired reaction to occur

95
Q

infiltration

A

permeation, as in paraffin permeating tissue. Infiltration is also known as impregnation

96
Q

informatics

A

the practice of information processing

97
Q

ion exchange resin

A

a substance that exchanges one ion for another. ion exchange resins are used in decalcification and exchange ammonium ions for the calcium ions removed from the tissue. The formic acid used for decalcification is rapidly cleared of calcium ions, and thus daily solution changes are avoided

98
Q

isotonic

A

fluids that will cause animal cells to neither swell nor shrink. a 0.9% solution of sodium chloride (saline) or a 5% glucose solution is approximately isotonic

99
Q

laboratory information system

A

database used by the laboratory that securely maintains patient information and documents clinician and healthcare provider activities, orders, and results

100
Q

lake

A

the combination of a mordant (eg, aluminum) with a dye (eg, hematein). The dye-lake can bind to tissue components and form an insoluble colored deposit

101
Q

lipid

A

any of the numerous fats and fatlike materials that are generally insoluble in water but soluble in common organic solvents

102
Q

lipofuscin

A

commonly referred to as “wear and tear” pigments, these yellow-brown pigments are probably breakdown products resulting from the oxidation of lipids and lipoproteins

103
Q

lymphoma

A

a malignant tumor that arises in lymph nodes, spleen, bone marrow, blood, or other organs when B or T lymphocytes divide faster and live longer than normal

104
Q

magnification

A

the enlargement of an optical image. the magnification of a microscopic image is calculated by multiplying the magnification of the ocular and the objective used

105
Q

empty magnification

A

an enlargement or magnification of a microscopic image without any further useful information being obtained

106
Q

medical record number

A

unique patient identifier used in association with encounter numbers. This number identifies the patient at each step o their care and associates all record keeping activities; that is, diagnostic reporting, healthcare records, and billing that is maintained in a health system permanent repository for each patient

107
Q

meniscus

A

the curved upper surface of a non turbulent liquid in a container. The surface is typically concave as the surface of the container is wet by the liquid

108
Q

mesothelioma

A

a form of cancer arising from the cells of the mesothelium, a protective layer of cells covering or lining many internal organs. Mesotheliomas most often are caused by exposure to asbestos

109
Q

metachromasia

A

a change of color. certain tissue elements stain metachromatically with certain dyes in that they give a color that differs from that of the stain used. Mast cell granules stain metachromatically toluidine blue in that they give a rose to violet color against the normal blue (orthochromatic) staining of the background

110
Q

metallic impregnation

A

the deposit of silver or gold on or around, but not in, the tissue component to be demonstrated. The metal is then reduced to its visible metallic form either by the tissue or by a reducing agent

111
Q

microincineration

A

heating microscope sections at a very high temperature (~650C). All organic material is burned off and the inorganic residue can be studied

112
Q

micrometer (uM, formerly micron)

A

1 millionth 10^-6 of a meter

113
Q

micrometry

A

the measurement of minute distances with the microscope

114
Q

microtomy

A

the cutting of thin sections of tissue for microscopic examination

115
Q

middleware

A

data processing software from a vendor or third party that’s function is to connect a laboratory instrument with a laboratory information system. The software links or “sits between” the operating systems of teh instruments and the LIS

116
Q

milliliter (mL)

A

a unit of volume measurement. 1 milliliter is equal to 10^-3 liters. milliliter is used interchangeably with cubic centimeter (cc).

117
Q

mineral

A

any naturally occurring, homogeneous inorganic substance having a definite chemical composition and characteristic crystalline structure. minerals can be studied by microincineration in addition to the frequent demonstration by chemical stains

118
Q

miscible

A

capable of mixing or being mixed

119
Q

monoclonal

A

derived from a single clone of cells, such as an antibody

120
Q

mordant

A

a reagent used to link the stain, or dye molecules, to the tissue. Many mordants in histology are metals, especially those linking hematein to tissue (ie aluminum, tungsten, iron, and chromium)

121
Q

mycelium

A

a fungal colony composed of a mat of intertwined hyphae

122
Q

myo-

A

a prefix denoting muscle

123
Q

myobacteria (singular mycobacterium)

A

a genus of slender, rod shaped bacteria. included are the causative organisms of tuberculosis and leprosy

124
Q

myelin

A

a white fatty material encasing and providing a protective sheath for some nerve fibers

125
Q

nanometer (nM)

A

1 billionth 10^-9 of a meter

126
Q

neoplasm

A

an abnormal new growth of tissue

127
Q

neuron

A

a nerve cell

128
Q

neuroma

A

a benign tumor or swelling of the nervous tissue, including nerve fibers and their myelin sheath

129
Q

nissl substance

A

clumps of rough, or granular, endoplasmic reticulum. Because of the RNA content, Nissl substance stains sharply with basic aniline dyes such as thionin and cresyl echt violet

130
Q

noncoagulation

A

absence of clot formation

131
Q

objective

A

the lens at the lower end of the barrel, or body tube, of the microscope. several objectives, yielding different magnifications, are found on most microscopes

132
Q

ocular

A

the eyepiece of the microscope, or the lens found at the upper end of the barrel or body tube

133
Q

-ology

A

a suffix denoting an area of knowledge or a branch of science

134
Q

-oma

A

a suffix denoting a swelling of tumor

135
Q

orthochromatic

A

dyes that stain tissue components as expected or the same color as the dye solution

136
Q

osmolality

A

the concentration of osmotic solutions expressed in terms of particles in solution. 1 osmol is the number of particles in a gram molecular weight of undissociated solute. If the solute dissociates into 2 ions, 1 g molecular weight of the solute equals 2 osmols

137
Q

oxidation

A

occurs by combining with oxygen, by the loss of hydrogen, or by the loss of electrons. Hematoxylin is oxidized to hematein by the loss of hydrogen

138
Q

oxidizing agent

A

a substance that causes oxidation. hematoxylin is oxidized to hematein by either chemical means or by light and air. for some staining techniques, certain tissue components are oxidized to a more reactive state , such as the oxidation of some carbohydrates to aldehydes by either periodic acid or chromic acid prior to the schiff reaction

139
Q

parfocal

A

in the same plane of focus. microscope objectives are said to be parfocal when they can be changed without the need to refocus

140
Q

pathology

A

a medical specialty concerned with the diagnosis of disease

141
Q

permissible exposure limit PEL

A

the maximum allowable 8 hour time weithed average of exposure to a substance as defined by OSHA. the PEL is expressed in parts per million ppm

142
Q

phosphatase

A

a hydrolytic enzyme that breaks the bond between an alcohol and a phosphate group. Phosphatases are present in a wide variety of plant and animal tissue. some phosphatases such as adenosine triphosphatase (ATPase) act specifically on a single substrate; others act with less substrate specificity and are divided into 2 groups: alkaline phosphatases (optimal in alkaline pH) and acid phosphatases (optimal at low pH)

143
Q

phosphorylase

A

a transferase that transfers phosphate groups. Phosphorylases are widely distributed in animal and plant tissues, and they catalyze a number of reversible reactions, leading to the synthesis and decomposition of saccharides. Glycogen phosphorylase is the best known phosphorylase.

144
Q

pigments

A

a heterogeneous group of substances that contain enough natural color to be visible without any further staining. examples are melanin, a brownish black pigment normally found in skin, hair, and eyes; and hematin (formalin pigment), a brownish black pigment found in blood rich tissues fixed in acidic formalin solution

145
Q

polarization

A

the examination of slides by using a polarizer and an analyzer to obtain light vibrating only in one plane. Anisotropic or birefringent material will be bright against a dark background if the optical paths of the polarizer and analyzer are crossed

146
Q

polychromatic

A

describes a single dye solution that stains tissue components different colors by a phenomenon other than metachromasia. One example is a solution prepared from a dye that is not pure but contains several dyes. The variety of color in the tissue is due to the selective adsorption of the different dye components by various tissue elements

147
Q

polymer

A

a covalently bonded chain of individual building blocks called monomers

148
Q

polymer detection system

A

a polymer with an enzyme label chemically attached in the place of biotin, typically used in 2 step detection system

149
Q

polymerization

A

a chemical reaction in which 2 or more small molecules join together to form a larger molecule containing repeating structural units of the original molecules. Formaldehyde tends to polymerize into paraformaldehyde; methanol is added to stock formaldehyde solutions to retard polymerization

150
Q

polysaccharide

A

a group of 9 or more monosaccharides joined by glycosidic bonds. Starch and cellulose are examples.

151
Q

precipitate

A

to separate from solution, usually caused by chemical action. in the Prussian blue reaction, iron is dissolved by hydrochloric acid and then immediately precipitated by potassium ferrocyanide. The ferric ferrocyanide precipitate is known as Prussian blue

152
Q

preservative

A

a fluid that will neither shrink nor swell tissue, will neither dissolve not distort its constituent parts , will kill bacteria and molds, and will render enzymes inactive. Unlike a fixative, a preservative will not alter or modify tissue constituents in such a way that they retain their form during the subsequent processing steps

153
Q

progressive staining

A

staining to the desired intensity and stopping the stain. No differentiation step is used

154
Q

protozoans (singular protozoan)

A

single celled animals that are simple structurally but complex functionally

155
Q

pseudo-

A

a prefix denoting something false or pretending to be something it is not

156
Q

pseudomelanin

A

a brownish yellow pigment sometimes seen in the lamina propria of the colon, appendix, and rarely the small intestine. The pigment gives positive Fontana-Masson and Schmorl reactions

157
Q

reduction

A

accomplished through the loss of oxygen, or by the gain of hydrogen or electrons

158
Q

refractive index

A

the ratio of the speed of light in a vacuum to the speed of light in the medium under consideration

159
Q

regressive staining

A

the tissue is over stained and then decolorized, or differentiated, until the desired component contrasts sharply with the background. The Verhoeff elastic stain is an example of regressive staining

160
Q

resolution

A

the optical ability to distinguish two objects a minimal distance apart as two objects. The light microscope has a resolving power of 0.2um. Two objects closer together than 0.2um will be seen as one object

161
Q

rhabdo-

A

a prefix meaning rod shaped or pertaining to a rod

162
Q

ripening

A

oxidation, as in the ripening of hematoxylin to hematein

163
Q

sarcoma

A

a malignant growth arising from transformed cells of mesochymal origin (eg, bone, cartilage, connective tissue proper)

164
Q

short term exposure limit STEL

A

the maximum allowable time weighted exposure for any 15 minute period during an 8 hour work period

165
Q

solute

A

the substance or chemical being dissolved

166
Q

solvent

A

the liquid in which a substance is being dissolved

167
Q

spirochetes

A

spiral or corkscrew shaped argyrophilic bacteria

168
Q

substrate

A

the substance on which an enzyme acts

169
Q

supernatant

A

the liquid or fluid on top

170
Q

time weighted average

A

the amount of substance a worker is exposed to averaged over an 8 hour period

171
Q

tophus

A

a deposit of urate crystals in tissue

172
Q

universal precautions

A

safeguards or barriers used to minimize or prevent contact with blood or other potentially infectious material

173
Q

universal solvent

A

chemical reagent that can be used for both the dehydrating and clearing steps in tissue processing. Dioxane, tertiary butanol, and tetrahydrofuran are universal solvents

174
Q

urothelium

A

transitional epithelium lining much of the urinary tract (renal pelvis, bladder, ureter

175
Q

validation

A

confirmation through a defined process that a test performs as intended or claimed. New procedures for tissue processing or staining must be validated; this involves procedures on new instrumentation, relocated instruments, or changes in methodology

176
Q

verification

A

ensuring that a new product (eg, instrument or reagent) is capable of achieving the performance required and that it performs in agreement with the manufacturer’s claims. Instruments must be reverified if relocated

177
Q

yeasts

A

true fungi, usually single celled, oval shaped fungi that reproduce by budding at the smaller end of the cell

178
Q

validation.

A

establishing documented evidence that a process or system, when operated within established parameters, can perform effectively and reproducibly to meet the expected outcome

Histology Fall 2019 (31 decks)

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