Histology

Front 1

Which fixative contains picric acid, formalin, and acetic acid?

Back 1

Bouins

Front 2

Precipitate left in tissues that have been fixed in solutions containing mercuric chloride may be removed by immersion in:

Back 2

iodine

Front 3

Formalin pigment is most likely to form in tissues if the pH of the formalin solution is at or below?

Back 3

5.0

Front 4

A good fixative for central nervous system tissue to be stained with silver or gold techniques is:

Back 4

Formalin ammonium bromide

Front 5

After fixing tissue in Bouin solution, the excess picric acid is frequently removed by washing in:

Back 5

50%-70% ETOH

Front 6

Substitution of alcohol as the diluting solution for formaldehyde results in:

Back 6

better preservation of glycogen

Front 7

Which fixative will leave the protein uncoagulated?

Back 7

Osmium tetroxide

Front 8

To prevent polymerization of formaldehyde, what is added to the commercial stock solutions?

Back 8

methyl alcohol

Front 9

Potassium dichromate increases availability of which group for binding?

Back 9

NH2

Front 10

Acetic acid is an excellent fixative:

Back 10

TRUE

Front 11

Formalin penetrates rapidly but fixes slowy:

Back 11

TRUE

Front 12

10% formalin is a 1:4 dilution of commercial formalin

Back 12

FALSE

Front 13

Zenker fixative contains formalin, mercuric choride, and potassium dichromate

Back 13

FALSE

Front 14

Bouin solution contains picric acid, formalin, and hydrochloric acid

Back 14

FALSE

Front 15

Mercury crystals may be reoved from tissue by immersion in sodium thiosulfate.

Back 15

FALSE

Front 16

Formalin ammonium bromide is a very good fixative for connective tissue.

Back 16

FALSE

Front 17

B-5 fixative contains formalin and potassium dichromate.

Back 17

FALSE

Front 18

Gluteraldehyde is frequently used to fix specimens for electron microscopy.

Back 18

TRUE

Front 19

Blocked tissue, which had been fixed in Bouin solution, is pulled from the file after being stored for several years. New sections are cut and stained with H&E. No nuclear staing is noted on the new sections, although the original sections stained very well.

Back 19

Picric acid was not removed sufficiently before blocking.

Front 20

Electron Microscopic studies on a section of tumor fixed in 10% neutral buffered formalin reveal very poor cell preservation. This could be prevented in the future by:

Back 20

Fixing some of the tumor in glutaraldehyde solution.

Front 21

Tissue must be washed in running water after fixation in

Back 21

Zenker solution

Front 22

Which fixative contains formalin, potassium dichromate, and mercuric chloride?

Back 22

Helly

Front 23

Commercial stock formaldehyde solutions contain

Back 23

37%-40% formaldehyde

Front 24

Is Carnoy fixative nonaqueous

Back 24

Yes

Front 25

Fat is well perserved by Carnoy solution

Back 25

FALSE

Front 26

Formalin ammonium bromide is a very good fixative for connective tissue

Back 26

FALSE

Front 27

Helly, Zenker, and Orth all contain mercury

Back 27

FALSE

Front 28

B-5 Fixative contains formalin and potassium dichromate

Back 28

FALSE

Front 29

What is a dehydrating agent?

Back 29

alcohol

Front 30

What is a dehydrating agent?

Back 30

alcohol

Front 31

A clearing agent for use in processing tissues for paraffin embedding must be miscible with the:

Back 31

dehydrant and parrafin

Front 32

Dioxane is a reagent that can be used:

Back 32

for both dehydrating and clearing tissues

Front 33

A reagent that CANNOT be used for dehydrating tissue is:

Back 33

benzene

Front 34

Most commonly,the paraffin used for embedding tissues is kept at approximately:

Back 34

60 C

Front 35

A disadvantage of the use of dioxane in processing tissues is that it is:

Back 35

toxic

Front 36

The chief objection to the use of xylene as a clearing agent for processing tisssues is that xylene is:

Back 36

likely to harden tissue

Front 37

A good paraffin for routine use is one with a melting point of:

Back 37

55 C to 58 C

Front 38

Which of the following chemicals is NOT a clearing agent?

Back 38

ethanol

Front 39

Overheating of the parraffin used to embed may cause:

Back 39

cracking of the block

Front 40

One advantage of the paraffin technique is that:

Back 40

serial sections are easy to obtain

Front 41

When cutting paraffin embedded tissues, if the tissue seems hard and brittle, one source of trouble is likely to be:

Back 41

overheated paraffin

Front 42

The process of removing water from tissue is called:

Back 42

dehydration

Front 43

Reagents that both clear and dehydrate are called:

Back 43

universal solvents

Front 44

Paraffin that is considered soft:

Back 44

is most useful when thick sections are desired

Front 45

When used for clearing, cedar wood oil must be followed by:

Back 45

xylene

Front 46

Paraffin is cooled as rapidly as possible after embedding tissue in order to:

Back 46

prevent the formation of large crystals

Front 47

The dehydration and clearing steps can be omitted when using:

Back 47

water-soluble wax

Front 48

Specimens for electron microscopy are embedded in glycol methacrylate.

Back 48

False

Front 49

Sections processed by the celloidin method show less shrinkage than when processed by the paraffin technique.

Back 49

True

Front 50

The most appropriate method of processing tissue for most enzyme demonstration is frozen sections.

Back 50

True

Front 51

Overheating of the paraffin used for infiltration causes shrinkage and overhardening of the tissue.

Back 51

True

Front 52

Skin sections ar embedded so that the epithelial surface is faced down in the block.

Back 52

False

Front 53

Ion exchange resin and electrolytic methods of decalcification fall under the broad heading of acid methods.

Back 53

True

Front 54

When undecalcifed bone is to be sectioned, it must be embedded in Carbowax.

Back 54

False

Front 55

Heating the solution is a good method of increasing the rate of decalcification.

Back 55

False

Front 56

Tissue will contain ice crystal artifacts when frozen slowly.

Back 56

True

Front 57

Tissues are usually infiltrated with paraffin directly from an essential oil.

Back 57

False

Front 58

A chelating agent exchanges another ion for the calcium ion.

Back 58

False

Front 59

Carbowax is a blend of liquid polyethylene glycol and wax.

Back 59

True

Front 60

One result of incomplete clearing is poor infiltration with Carbowax.

Back 60

False

Front 61

Bone sections should be embedded parallel to the long axis of the block.

Back 61

False

Front 62

If phosphate-buffered formalin fixation is followed by dehydration beginning with 80% alcohol, phosphates may be precipitated.

Back 62

True

Front 63

The best method of checking Zenker-fixed tissue for the completeness of decalcification is radio-logic examination.

Back 63

False

Front 64

Xylene and toluene are aromatic hydrocarbons.

Back 64

True

Front 65

One cause of uneven staining with H&E may be water contamination of the clearing agent on the processor.

Back 65

True

Front 66

During microtomy,it is noted that most of the tissue is very hard and shrunken. One of the first things to check to prevent its happening in the future is the:

Back 66

temperature of the infiltrating paraffin

Front 67

H&E-stained sections show very uneven staining of the tissue, with poor nuclear detail. One possible cause is:

Back 67

water in the clearing agent

Front 68

Phosphate-buffered formaldehyde is used in the first two stations of the closed processor. A white precipitate is forming in the processor tubing, and the tissue is more difficult to cut than usual. One of the first things to check to correct the problem is the:

Back 68

percent alcohol used as the first dehydrant

Front 69

At microtomy,formalin-fixed, paraffin-embedded kidney sections are soft and mushy. This is most likely due to:

Back 69

inadequate dehydration and clearing

Front 70

Aqueous unbuffered zinc formalin is used at the first stage on the closed processor, followed by phosphate-buffered formalin and 65% alcohol. It is noted that a white precipitate is forming on the processor tubing. This precipitate is most likely due to:

Back 70

the formation of zinc phosphate

Front 71

Many of the zinc formalin-fixed biopsy specimans are hard and brittle and show microscopic chatter. This will result if the specimans are:

Back 71

processed incorrectly

Front 72

The ability of the microscope to separate small details is defined as:

Back 72

resolution

Front 73

Sections 90-nm thick are commonly cut with a/an:

Back 73

ultramicrotome

Front 74

Tissues embedded in glycol methacrylate are commonly cut with a/an:

Back 74

rotary microtome

Front 75

The regular laboratory incubator maintains a temperature of about:

Back 75

37 C

Front 76

When the magnification can be changed without the need to refocus, the microscope objectives are said to be:

Back 76

parfocal

Front 77

If a ribbon splits when cutting paraffin sections, the trouble is most likely due to:

Back 77

nicks in the knife

Front 78

The bevel angle of most American manufactured knives is:

Back 78

28-32 degrees

Front 79

The temperature of the oven used to maintain a supply of melted paraffin for embedding tissue should be about:

Back 79

60 C

Front 80

Doubly refractile particles are examined using:

Back 80

polarized light

Front 81

Crooked paraffin ribbons may be caused by

Back 81

nonparallel block horizontal edges

Front 82

When using a microscope with x10 ocular and a x40 objective, the total magnification is approximately:

Back 82

400

Front 83

The clearance angle of the microtome knife should be:

Back 83

3 to 8

Front 84

The ordinary refrigerator, when operating normally, has a temperature that approaches:

Back 84

4 C

Front 85

When a lens for a light microscope has been corrected for two colors, it is said to be :

Back 85

achromatic

Front 86

When using paraffin with a melting point of 55 C to 57 C, the most common temperature for floating sections on a flotation bath is approximately:

Back 86

45 C to 50 C

Front 87

Compressed or wrinkled sections may be caused by:

Back 87

too little knife tilt

Front 88

The scanning objective on the light microscope is found:

Back 88

at the lower end of the body tube

Front 89

Various sized holes are noted in sections of paraffin-embedded liver on the flotation bath. With further ribboning, these holes decrease in size and disappear. The most likely cause of the holes is :

Back 89

facing the block too aggressively

Front 90

Birefringent substances are best examined with which of the following microscopes?

Back 90

polarizing

Front 91

During microtomy, the sections lift from the knife as the block is raised. The most likely cause is:

Back 91

a dull knife

Front 92

Microscopic examination of an H&E-stained section reveals marked chatter, especially at the edges of the tissue. This was most likely caused by:

Back 92

overdehydration of the tissue

Front 93

During cryotomy, sections of varying thickness are obtained. This can most likely be corrected by:

Back 93

increasing the knife tilt

Front 94

When checking the pH of a staining solution,the pH meter should be calibrated using a standard solution with a pH value:

Back 94

closest to that of the staining solution