Exam 1 9/13 Howard Intro to Histology

Question 1

Another name for histology

Answer 1

Microanatomy

Question 2

Methods for viewing tissue

Answer 2

Conventional Light Microscopy
Confocal light microscopy
Transmission Electron microscopy
Scanning electron microscopy
X-ray
Computer Axial Tomography
Magnetic resonance imaging
Positron emission tomography

Question 3

Which method of viewing tissue will we normally see/sometimes see?

Answer 3

Conventional light microscopy; transmission electron microscopy

Question 4

True or false: confocal microscope has only one lens

Answer 4

False - more than a single lens

Question 5

What magnifications are possible with a compound light microsope?

Answer 5

40, 100, 400, 1000x

Question 6

True or false: electron microscopes can provide a 2D and 3D image

Answer 6

True

Question 7

Transmission electron microscope provides what kind of image?

Answer 7

2D

Question 8

Scanning electron microscope provides what kind of image?

Answer 8

3D

Question 9

True or false: you cannot see small molecules with an electron microscope

Answer 9

False - can see up to 1nm which is the size of some small molecules, like glucose

Question 10

Approximate size of cell nucleus

Answer 10

1-10 micrometers

Question 11

Resolution of light microscope

Answer 11

200 nm

Question 12

When viewing artifacts, what is your ruler?

Answer 12

identify different cells and nucleus as a reference point

Question 13

What affects the appearance of artifacts?

Answer 13

1. Preservation/fixation
2. embedding
3. sectioning
4. staining

Question 14

What is usually used in fixation of a specimen?

Answer 14

37% buffered formaldehyde

Question 15

What is usually used to embed a specimen?

Answer 15

Paraffin wax

Question 16

What is usually used to stain a specimen?

Answer 16

H&E (hemotoxylin and eosin)

Question 17

True or false: when preserving a specimen, they are hydrated, dehydrated, then rehydrated again

Answer 17

False - first dehydrated, rehydrated, then dehydrated to apply stain

Question 18

True or false: thinner section allow for better resolution

Answer 18

True

Question 19

Embedding methods

Answer 19

1. frozen
2. paraffin
3. plastic

Question 20

Pros and cons of frozen specimen

Answer 20

Pros:
1. quick to retrieve, cut, stain
2. can preserve antibody-antigen complexes

Cons:
1. can destroy antibody-antigen complexes
2. morphologically destructive
3. poor resolution

Question 21

Pros and cons of embedding specimen in paraffin wax

Answer 21

Pros:
1. very standardized
2. standardized interpretation
3. mostly preserve antibody-antigen complexes

Cons:
1. long fixation times
2. resolution can vary with technician

Question 22

Pros and cons of embedding specimen in plastic

Answer 22

Pros:
1. very good resolution
2. water soluble plastic retains lipids

Cons:
1. long fixation times
2. interpretation can vary depending on procedure
3. destroys antibody-antigen complexes

Question 23

What is used to section specimen?

Answer 23

microtome, cryomicrotome

Question 24

How thin should a frozen section be?

Answer 24

5-100 micrometers

Question 25

How thin should paraffin sections be?

Answer 25

2-50 micrometers

Question 26

Plastic for light microscopy section size

Answer 26

0.5-2 micrometers

Question 27

Plastic for electron microscopy section size

Answer 27

40nm - 100nm

Question 28

3 classes of staining:

Answer 28

1. differentiate between acidic and basic components of cell 2. differentiate fibrous components of ECM 3. metallic salts that precipitate metal deposits on tissues

Question 29

Acid stain

Answer 29

Eosin; negatively charged dye; stains basic structures in cytoplasm and mitochondria, structures are acidophilic

Question 30

Basic stain

Answer 30

Hematoxylin; positively charged dye; stain acidic structures (DNA and RNA); these structures are basophilic

Question 31

What color does hematoxylin stain?

Answer 31

Blue (dna and rna)

Question 32

What color does eosin stain?

Answer 32

Pink (Basic proteins in cytoplasm - collagen, elastin, reticular fibers, but can't distinguish)

Question 33

What does H&E not stain?

Answer 33

Lipids - they are lost in preparation, as they are soluble in dehydration reaction alcohols

Question 34

Silver stain can stain:

Answer 34

reticular fibers black (type III collagen)

Question 35

Weigert's elastic stain

Answer 35

Blue - elastic fibers

Question 36

Periodic acid-schiff

Answer 36

Magenta - glycogen and carbohydrate rich molecules

Question 37

4 Primary tissue types

Answer 37

1. Epithelial 2. Connective 3. Muscle 4. Nervous

Question 38

Epithelial tissue are specialized to:

Answer 38

protect, absorb, and secrete

Question 39

Epithelial tissue function

Answer 39

1. covers and lines (skin, lining of gut) 2. modified for absorption (gut lining) 3. modified for secretion (glands)

Question 40

Connective tissue is specialized for:

Answer 40

providing support and holding other tissues together

Question 41

What connective tissues are specialized?

Answer 41

blood/bone marrow, mineralized tissues (ex: teeth), fat storage

Question 42

______ tissue is highly specialized for contraction and conduction

Answer 42

Muscle

Question 43

____ tissue is highly specialized with respect to irritability and conductivity

Answer 43

Nervous