CHAPTER 1 Pt. 1 Histology and Its Methods of Study

Question 1

The study of tissues of the body and how these tissues are arranged to constitute organs

Answer 1

Histology

Question 2

Tissue’s 2 interacting components

Answer 2

cell; extracellular matrix

Question 3

ECM two components

Answer 3

fibers; ground substance

Question 4

supports the cells and contains the fluid transporting nutrients to the cells, and carrying away their wastes and secretory products

Answer 4

ECM

Question 5

produce the ECM locally and are in turn strongly influenced by matrix molecules

Answer 5

Cells

Question 6

many of the matrix components bind to _________________that span the cell membranes and connect
to structural components inside the cells, forming a continuum in which cells and the ECM function together in a well-coordinated manner.

Answer 6

specific cell receptors

Question 7

become functionally specialized and give rise to fundamental types of tissues with characteristic structural features.

Answer 7

cells and their associated matrix

Question 8

formed by an orderly combination of these tissues,
and their precise arrangement allows the functioning of each
organ and of the organism as a whole

Answer 8

Organs

Question 9

The most common procedure used in histologic research

Answer 9

preparation of tissue slices or “sections”

Question 10

most common microscope

Answer 10

bright field

Question 11

The ideal microscopic preparation is preserved so that the
tissue on the slide has the same structural features it had in the
body. However, this is often not feasible because the preparation process can remove ___________, with slight distortions
of cell structure.

Answer 11

cellular lipid

Question 12

Basic Steps used in tissue preparation for light microscopy (Fix, De, Cle, In, Em, Tri)

Answer 12

Fixation
Dehydration
Clearing
Infiltration
Embedding
Trimming

Question 13

most critical step in tissue processing

Answer 13

Fixation

Question 14

aka preservation

Answer 14

Fixation

Question 15

To preserve tissue structure and prevent degradation by
enzymes released from the cells or microorganisms, pieces of organs are placed as soon as possible after removal from the
body in solutions of stabilizing or cross-linking compounds
called __________

Answer 15

fixatives

Question 16

fixatives are often
introduced via blood vessels, with vascular perfusion allowing
fixation rapidly throughout the tissues to
improve ________________ in large organs

Answer 16

cell preservation

Question 17

widely used fixative for light microscopy

Answer 17

Formalin

Question 18

how does formalin form?

Answer 18

Formaldehyde is dissolved in water forming 37% formaldehyde buffered isotonic solution

Question 19

fixative used for electron microscopy

Answer 19

formalin and glutaraldehyde

Question 20

formalin and glutaraldehyde react with _________ groups of proteins preventing their degradation by common proteases

Answer 20

amine (NH2)

Question 21

also cross-links adjacent proteins, reinforcing cell and
ECM structures.

Answer 21

Glutaraldehyde

Question 22

provides much greater magnification and resolution of very small cellular structures,
and fixation must be done very carefully to preserve additional “ultrastructural” detail.

Answer 22

electron microscopy

Question 23

For “ultrastructural” detail, glutaraldehyde-treated tissue is then immersed in

Answer 23

buffered
osmium tetroxide

Question 24

preserves (and stains) cellular lipids as well as proteins.

Answer 24

osmium tetroxide

Question 25

Embedding materials include ________, used routinely for light microscopy, and __________, which are adapted for both light and electron microscopy.

Answer 25

paraffin; plastic resins

Question 26

having its water extracted gradually

Answer 26

dehydration

Question 27

reagent for dehydration

Answer 27

ethanol

Question 28

alternative reagent for dehydration

Answer 28

Isopropanol

Question 29

clearing is aka

Answer 29

dealcoholization

Question 30

The ethanol is then replaced by an organic solvent miscible with both alcohol and the embedding medium; infiltration with the reagents used here gives the tissue a translucent appearance.

Answer 30

clearing

Question 31

reagent for Clearing

Answer 31

cylin (cylon)

Question 32

alternative reagent for clearing

Answer 32

toluene

Question 33

The fully cleared tissue is then placed in melted paraffin in an oven at 52°-60°C, which evaporates the clearing solvent and promotes ________ of the tissue with _______

Answer 33

inflitration; paraffin

Question 34

paraffin _________spaces in tissue

Answer 34

infiltrates

Question 35

the infiltrated tissue is buried in

Answer 35

paraffin wax

Question 36

embedded by allowing it to harden in a small container of paraffin at ___________.

Answer 36

room temperature

Question 37

Tissues to be embedded with _________ are also dehydrated in ethanol and then infiltrated with plastic solvents that harden when cross-linking polymerizers are added

Answer 37

plastic resin

Question 38

avoids the higher temperatures needed with paraffin, which helps avoid tissue distortion.

Answer 38

Plastic embedding

Question 39

The hardened block with tissue and surrounding embedding medium is trimmed and placed for sectioning in an instrument called a

Answer 39

a microtome

Question 40

Paraffin sections are typically cut at ______ thickness for light microscopy

Answer 40

3-10 μm

Question 41

electron microscopy requires sections less than _____ thick

Answer 41

1 μm

Question 42

A microtome called a ________in a cabinet at subfreezing temperature is used to section the block with tissue, and the frozen sections are placed on slides for rapid staining and microscopic examination by a pathologist.

Answer 42

cryostat

Question 43

embedding aka

Answer 43

casting/blocking

Question 44

microtome aka

Answer 44

rotary/minot

Question 45

Cell components with a net negative charge (anionic), have an affinity for

Answer 45

basic dyes

Question 46

have an affinity for basic dyes and are termed

Answer 46

basophilic

Question 47

Cell components with cationic components, such as proteins with many ionized amino groups, stain more readily with

Answer 47

acidic dyes

Question 48

proteins with many ionized amino groups, stain more readily with acidic dyes and are termed ___________.

Answer 48

acidophilic

Question 49

Examples of basic dyes include

Answer 49

toluidine blue alcian blue methylene blue.

Question 50

a dye that has net + charge attracting substances that are negatively charged

Answer 50

basic dye

Question 51

a dye that has net - charge repelling a negatively charged substances

Answer 51

acidic dye

Question 52

simple combination of staining methods

Answer 52

hematoxylin and eosin (H&E)

Question 53

Hematoxylin stains:

Answer 53

1. DNA in the cell nucleus 2. RNA-rich portions of the cytoplasm 3. matrix of cartilage

Question 54

Eosin is considered a ____

Answer 54

counterstain - to distinguish additional features of a tissue

Question 55

utilizes the hexose rings of polysaccharides and other carbohydrate-rich tissue structures and stains such macromolecules distinctly purple or magenta

Answer 55

periodic acid–Schiff (PAS) reaction

Question 56

The DNA of cell nuclei can be specifically stained using a modification of the PAS procedure called the

Answer 56

Feulgen reaction.

Question 57

Lipid-rich structures of cells are revealed by avoiding the processing steps that remove lipids, such as treatment with heat and organic solvents, and staining with lipid-soluble dyes such as _____

Answer 57

Sudan black

Question 58

typically using solutions of silver salts to visual certain ECM fibers and specific cellular elements in nervous tissue.

Answer 58

metal impregnation techniques