L1 Orientation to Histology

Question 1

What are the 4 basic tissue types?

Answer 1

1. Epithelium (covers, lines, secretes, absorbs)
2. Connective tissue (structural support)
3. Muscle (contracts to produce movement)
4. Nervous tissue (integrates sensory information with motor outcomes)

Question 2

Purpose of magnification of microscopy?

Answer 2

Expressed as ratio of image size to object size (eg 10x, 400x, 1000x)

Question 3

How is resolution measured?

Answer 3

Measured in microns or nanometers

Question 4

What are features of LM?

Answer 4

Light microscopy

• Photons of light interact with tissue components
• Light is focused with optical lens

Question 5

What are features of EM? (3)

Answer 5

Electron microscopy

• Electrons interact with tissue components
• Electrons are focused with electromagenetic lens
• Smaller wavelength = increased resolution

Question 6

What are the 2 types of EM?

Answer 6

1. Transmission electron microscopy (TEM)

2. Scanning electron microscopy (SEM)

Question 7

What are features of TEM?

Answer 7

• Shows internal structure

- There is a freeze fracture technique

Question 8

What are features of the SEM?

Answer 8

Scanning electron microscopy

- Shows external (or surface) structure

Question 9

Combination of microscopy techniques is good or bad?

Answer 9

Good, because they complement and improve our understanding of cells and tissue

Question 10

General concepts of staining (4 words)?

Answer 10

1. Fixation
2. Embedding
3. Sectioning
4. Staining

Question 11

What are two main types of stains/ dyes?

Answer 11

1. Basophilic

2. Acidophilic

Question 12

What do basophilic stains do?

Answer 12

Stains acid, appear blue/purple, example include RNA/DNA/Glycosaminoglycans

Question 13

What do acidophilic stains do?

Answer 13

Stains bases, appears pink/red/orange, example include cytoplasm, collagen fibers

Question 14

What are examples of basophilic and acidophilic stain types?

Answer 14

Basophilic- Hematoxylin

Acidophilic- Eosin

Question 15

What is the best/ most common stain?

Answer 15

Hematoxylin & Eosin (H & E)

Question 16

What does the Periodic-acid Shiff (PAS) stain?

Answer 16

Carbohydrate into magenta or purple color (eg glycoproteins)

Question 17

What does trichrome stain?

Answer 17

Stains collagen fibers a blue or green color

Question 18

What does silver stain?

Answer 18

Reticular fibers BLACK

Question 19

What does Orcein stain?

Answer 19

Stains elastic fibers reddish-brown or black

Question 20

Tips for looking at histological images (low-high power)?

Answer 20

Low- no individual cells
Intermediate- tissue organization
High- cell/nuclear detail

Question 21

What are artifacts?

Answer 21

Something artificially made by people- tissue shrinkage and lost molecule

Question 22

What is microanatomy?

Answer 22

Study of cells and tissues