UNIT 1 - Introduction to Histology

Question 1

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

Answer 1

Histology

Question 2

Other name for histology

Answer 2

Microscopic anatomy or microanatomy

Question 3

Where was the word tissue derived from?

Answer 3

French word “Tissu” – weave or texture

Question 4

What year was tissue not referred to organic, cellular layers, but rather to anything woven or textured?

Answer 4

1700s

Question 5

What was the name of the French scientist that coined tissue in histology?

Answer 5

Bichat

Question 6

Where were the first microscopes constructed?

Answer 6

Netherlands

Question 7

What year were the first microscopes constructed?

Answer 7

Late 1500s

Question 8

Known as the possible inventor of the microscope

Answer 8

Zacharias Janssen

Question 9

Four basic types of tissues

Answer 9

Epithelial, connective, muscle, nervous

Question 10

Involves all aspects of tissue biology, with the focus on how cells’ structure and arrangement optimize functions specific to each organ

Answer 10

Histology

Question 11

Use lens to magnify objects

Answer 11

Light microscopes

Question 12

specific place where light rays focus

Answer 12

focal point

Question 13

Distance between center of lens and focal point

Answer 13

Focal length

Question 14

Types of light microscopes

Answer 14

o bright-field microscope
o dark-field microscope
o phase-contrast microscope
o fluorescence microscope
o confocal microscope

Question 15

Produces a dark image against a brighter background

Answer 15

bright – field microscope

Question 16

product of the magnifications of the ocular lenses and the objective lenses

Answer 16

total magnification

Question 17

Ability of a lens to separate or distinguish small objects that are close together

Answer 17

Microscope resolution

Question 18

major factor in resolution

Answer 18

wavelength of light

Question 19

distance between the front surface of lens and surface of cover glass or specimen when it is in sharp focus

Answer 19

working distance

Question 20

If air is replaced with immersion oil, many light rays that did not enter the objective due to reflection/refraction at the surfaces of the objective lens and slide will now do so.

Answer 20

Oil immersion objective

Question 21

Properties of objective lenses

Answer 21

Scanning, low power, high power, oil immersion

Question 22

Image is formed by light reflected or refracted by specimen

Answer 22

Dark – field microscope

Question 23

Produces a bright image of the object against a dark background

Answer 23

Dark field microscope

Question 24

microscope used to observe living, unstained preparations

Answer 24

Dark field microscope

Question 25

Converts differences in refractive index/cell density into detected variations in light intensity

Answer 25

Phase contrast microscope

Question 26

dark against bright background

Answer 26

phase contrast microscope

Question 27

Creates image by detecting differences in refractive indices and thickness of different parts of specimen

Answer 27

Differential interference contrast microscope (DIC)

Question 28

Exposes specimen to ultraviolet, violet, or blue light. Specimens usually stained with fluorochromes

Answer 28

Fluorescence microscope

Question 29

Shows a bright image of the object resulting from the fluorescent light emitted by the specimen

Answer 29

Fluorescence microscope

Question 30

creates sharp, composite 3D image of specimens by using laser beam, aperture to eliminate stray light, and computer interface

Answer 30

confocal microscopy

Question 31

Numerous applications including study of biofilms

Answer 31

Confocal microscopy

Question 32

Use Beams of Electrons to Create Highly Magnified Images

Answer 32

Electron microscopy

Question 33

Wavelength of electron beam is much shorter than light, resulting in much higher resolution

Answer 33

Electron microscopy

Question 34

Allows for study of microbial morphology in great detail

Answer 34

Electron microscopy

Question 35

Transmitted electrons are under vacuum which reduces scatter and are used to produce clear image

Answer 35

Transmission electron microscope

Question 36

Denser regions in specimen scatter more electrons and appear darker

Answer 36

Transmission electron microscope

Question 37

Analogous to procedures used for light microscopy

Answer 37

Specimen preparation

Question 38

Specimens are chemically fixed and stained with electron dense materials, such as heavy metals, that differentially scatter electron

Answer 38

Specimen preparation

Question 39

allows for 3-D observation of shapes of intracellular structures and reduces artifacts

Answer 39

freeze etching

Question 40

T/F specimens must be cut very thin for Transmission electron microscopy

Answer 40

True

Question 41

Uses electrons excited from the surface of a specimen to create detailed image

Answer 41

Scanning electron microscope

Question 42

Produces a realistic 3D image of specimen’s surface features

Answer 42

Scanning electron microscope

Question 43

Can determine actual in situ location of microorganisms in ecological niches

Answer 43

Scanning electron microscope

Question 44

Rapid freezing technique provides way to preserve native state of structures examined in vacuum

Answer 44

Electron cryomatography

Question 45

Types of microscopy

Answer 45

Optical near field optical (NFOM) X-ray (TXM, SXM, STXM) Scanning Electron (SEM) Transmission electron (TEM, STEM) Focused ion beam (FIB) Scanning tunneling microscopy (STM) Atomic force microscopy (AFM) Magnetic Force Microscopy (MFM)

Question 46

Increases visibility of specimen, Accentuates specific morphological features, Preserves specimens

Answer 46

Preparation and staining of specimens

Question 47

make internal and external structures of cell more visible by increasing contrast with background

Answer 47

dyes

Question 48

two types of dyes

Answer 48

basic, acidic

Question 49

examples of basic dyes

Answer 49

Methylene blue, basic fuchsin, crystal violet, safranin, Malachite green

Question 50

Examples of acidic dyes

Answer 50

Eosin, rose bengal, and acid fuchsin – possess groups such as carboxyls (- COOH) and phenolic hydroxyls (-OH)

Question 51

Have positively charged groups; bind to negatively charged molecules

Answer 51

Basic dyes

Question 52

In their ionized form, have a negative charge and bind to positively charged cell structures

Answer 52

Acidic dyes

Question 53

Divides microorganisms into groups based on their staining properties

Answer 53

Differential staining

Question 54

used to detect presence or absence of structures

Answer 54

differential staining

Question 55

histotechniques

Answer 55

1. Numbering/labelling 2. Fixation 3. Dehydration 4. Clearing 5. Wax impregnation 6. Embedding 7. Blocking and trimming 8. Sectioning 9. Staining 10. Mounting 11. Labelling