Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Histology > Chapter 1 - Histology and Its Methods of Study > Flashcards

Chapter 1 - Histology and Its Methods of Study Flashcards

(63 cards)

Start Studying
1
Q

What are the steps of tissue preparation?

A

1- fixation
2- dehydration and clearing
3- embedding
4- sectioning
5- mounting and staining the sections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is fixation?

A

It is the treatment of a tissue with chemical agents for 12-24 hours to preserve its structure and prevent distortion by enzymes or bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What fixative agents are commonly used for fixation?

A
  • Formalin and Bouin’s fluid are used in light microscopy.
  • Glutteraldehyde and osmium tetroxide are both used in electron microscopy.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is dehydration?

A

It is the gradual removal of water from a tissue sample to facilitate the passage of light through the sample, prevent the sample from rotting, and allow for the complete penetration of paraffin wax.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is clearing?

A

It is the treatment of the tissue with xylene to help the penetration of wax into the tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is infiltration?

A

It is the incubation of a cleared specimen with melted paraffin at 52-60°C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What substances are used in embedding?

A
  • Paraffin is used in light microscopy.
  • Plastic resin is used in electron microscopy.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is sectioning?

A

It is the process in which the paraffin block is cut into small sections using a microtome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is embedding?

A

After full infiltration, the sample is left to harden at room temperature in a container of paraffin to form a paraffin block.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How thick should a tissue section be after sectioning?

A
  • 5-10 micrometers in light microscopy
  • less than 1 micrometer in electron microscopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is paraffin removed from a tissue sample before sectioning?

A

Paraffin is removed by the addition of xylene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is rehydration?

A

It is the gradual and slight hydration of the tissue sample by submerging it in solutions with decreasing ethanol concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What must be done before staining?

A

1- Paraffin must be removed.
2- The sample must be slightly rehydrated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is mounting?

A

It is the placement of tissue sections on adhesive-coated glass slides (in light microscopy) or mesh grids (in electron microscopy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the three classes of stains?

A

1- Stains that differentiate between acidic and basic components of the cell.
2- Specialized stains that differentiate the fibrous components of the extracellular matrix.
3- Stains that are used to dye accumulations of metallic salts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is prussian blue stain?

A

A stain that is commonly used to detect the presence of iron in tissue or cell samples.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is hematoxylin?

A

It is a base that colors the acidic components of the cell a bluish tint.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

define

basophilic

A

substances that are stained blue by hematoxylin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is eosin?

A

It is an acid that dyes the basic components of the cell a pinkish color.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

define

acidophilic

A

also known as eosinophilic
substances that are stained pink by eosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is toluidine blue?

A

It is a stain that is originally blue in color and dyes polyanions purple.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

define

metachromatic

A

a tissue or cell component that is stained purple by toluidine blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is Mason’s trichrome?

A

It is a specialized stain that dyes collagen blue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is Orcein’s elastic stain?

A

It is a specialized stains that dyes elastic fibers brown.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is Weigert’s elastic stain?
It is a specialized stains that dyes elastic fibers blue.
26
What is Silver stain?
It is a specialized stain that dyes reticular fibers black.
27
What is Periodic acid-Schiff (PAS)?
It is a specialized stains that dyes glycogen and carbohydrate-rich molecules magenta.
28
What are Wright’s and Giemsa stains?
They are stains that are used for differential staining of blood cells: - Erythrocytes and eosinophil granules are dyed pink. - The cytoplasm of monocytes and lymphocytes is dyed blue.
29
What is magnification?
It is the ratio between the size of an image produced by the microscope and its actual size.
30
What is resolution?
It is the smallest distance between two structures at which they can be seen as separate objects. It can be used as a measure of clarity of an image.
31
What is the resolving power of the light microscope?
0.2 micrometers
32
What is contrast?
It is the ability to visualize a particular cell structure depending on how different it looks from an adjacent structure.
33
What are the different types of light microscopes?
1- bright-field microscope 2- fluorescence microscope 3- phase-contrast microscope 4- differential interference microscope 5- confocal microscope 6- polarizing microscope
34
bright-field microscopy
stained preparations are examined by means of ordinary light that passes through the specimen
35
fluorescence microscopy
tissue sections absorb UV light and emit visible light to produce an image that appears as shiny particles on a dark background, which helps locate certain components
36
phase-contrast microscopy
the production of micrographs relies on the **differences in refractive index**, which allows the examination of living, cultured, and unstained cells
37
differential interference microscopy
cellular details are highlighted using Nomarski optics
38
confocal microscopy
a light microscope that uses a small point of high-intensity light and a plate with a pinhole aperture to avoid stray light and achieve greater resolution
39
polarizing microscopy
a light microscope that allows the recognition of stained or unstained structures made of highly organized subunits by passing light through two perpendicular polarizing filters
40
What is birefringence?
the ability to rotate the direction of vibration of polarized light
41
What are the types of electron microscopy?
1- transmission electron microscopy 2- scanning electron microscopy
42
transmission electron microscopy
a microscopy technique in which a beam of electrons is transmitted **through** a specimen to form an image
43
scanning electron microscopy
a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons
44
What is immunohistochemistry?
the incubation of a tissue section that is believed to contain a protein of interest in a solution containing an antibody to this protein
45
What are the two methods of immunocytochemistry?
1- direct method of immunocytochemistry 2- indirect method of immunocytochemistry
46
What is the direct method of immunocytochemistry?
the antibody itself is tagged with an appropriate label, such as a fluorescent compound or peroxidase
47
What is the indirect method of immunocytochemistry?
a secondary antibody made in a different foreign species against the primary antibody is labeled with a fluorescent compound or peroxidase
48
IHC could be used to diagnose … if **specific cytokeratins** were detected
tumors of epithelial origin
49
IHC could be used to diagnose … if some **proteins and polypeptide hormones** were detected
certain endocrine tumors
50
IHC could be used to diagnose … if a **carcinoembryonic antigen (CEA)** was detected
glandular tumors, mainly of the digestive tract and breast
51
IHC could be used to diagnose … if **steroid hormone receptors** were detected
breast duct cell tumors
52
IHC could be used to diagnose … if **antigens produced by viruses** were detected
specific virus infections
53
What is hybridization?
It is a technique that allows the specific identification of sequences of DNA or RNA by binding two single strands of nucleic acids that recognize each other if the strands are complementary
54
What is hybridization used for?
1- determining if a cell has specific sequence of DNA, such as a gene or part of a gene 2- identifying the cells containing specific mRNA 3- determining the localization of a gene in a specific chromosome
55
What is enzyme histochemistry?
*(also known as enzyme cytochemistry)* It is a method for localizing cellular structures using specific enzymatic activity present in those structures
56
What are some enzymes that can be detected histochemically?
1- **phosphatase**, which removes phosphate groups 2- **dehydrogenase**, which transfers hydrogen ions from one substrate to another 3- **peroxidase**, which promotes the oxidation of substances
57
How can molecules be detected using specific interactions between molecules?
A specific marcomolecule present in a tissue can be identified by using tagged compounds or other macromolecules that specifically interact with the material of interest
58
What labels are commonly used in detection methods that use specific interactions between molecules?
1- fluorescent compounds 2- radioactive atoms 3- molecules of peroxidase or other enzymes 4- metal particles (usually gold)
59
phalloidin interacts with … and is tagged with …
1- actin 2- fluorescent dyes
60
protein A binds to …. and can be used to locate …
1- the Fc region of immunoglobulin molecules (antibodies) 2- naturally occurring or applied antibodies bound to cell structures
61
lectins bind to … , are tagged by … , and are used to locate …
1- carbohydrates 2- fluorescent dyes 3- glycoproteins, proteoglycans, and glycolipids
62
What is autoradiography?
It is a method of localizing newly synthesized macromolecules by incorporating radioactively labeled metabolites to emit weak radiation where the molecules are located. Then, the radiolabeled cells are coated by silver bromide crystals, which act as microdetectors of this radiation by being reduced to grains of metallic silver
63
Why are cell cultures used?
1- to directly observe cellular behavior under a phase-contrast microscope 2- to carry out experiments that are impossible to perform in an intact animal

Histology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions