Question 1

What is the usual range of temperature of a water bath that removes the paraffin wax from the tissue?
A)50-60 degrees Celsius
B)45-50 degrees Celsius
C)35- 45 degrees Celsius
D)70-80 degrees Celsius

Accepted Answer

45 - 50 degree Celsius
The usual range of temperature of a water bath that removes the paraffin wax from the tissue is 45 - 50 degrees Celsius. The water bath is set at 45 - 50 degrees Celsius, approximately 6-10 degrees Celsius lower than the melting point of the wax used for embedding the tissue. All the other choices are inaccurate temperatures and do not effectively remove the paraffin wax from the tissue.

Question 2

The paraffin oven is maintained at what temperature?
A)5-10 degrees Celsius above the melting point of the paraffin used
B)10-12 degrees Celsius above the melting point of the paraffin used
C)2-5 degrees Celsius above the melting point of the paraffin used
D)4-8 degrees Celsius above the melting point of the paraffin used

Accepted Answer

2-5 degree Celsius above the melting point of the paraffin used
The paraffin oven is maintained at a temperature of 2-5 degree Celsius above the melting point of the paraffin used. This is the ideal temperature to maintain since higher temperatures can cause shrinkage of the tissues, which may damage the specimen. On the other hand, a lower temperature could not melt the paraffin efficiently to be used in impregnation. Therefore, all the other choices are not ideal temperatures for the paraffin oven to be effective.

Question 3

This is the procedure whereby lime salts are removed from the tissues following after fixation.
A)Dehydration
B)Decalcification
C)Impregnation
D)Clearing

Accepted Answer

Decalcification
The procedure whereby lime salts are removed from the tissues after fixation is called decalcification. This is a process where the samples containing calcium, such as bones and other calcified tissues, are subjected to the removal of calcium from the samples. All the other terms do not fit the description of decalcification.

Question 4

Calcium and other calcified materials may be removed from the tissue by any of the following agents, except:
A)Acids
B)Electrophoresis
C)Chelating agents
D)Oils

Accepted Answer

Oils
Calcium and other calcified materials may be removed from the tissue by any of the following agents except for oils. Oils are not used as a decalcifying agent for the reason that it will not remove the calcium found inside the tissue sample. All the other agents in the choices are used in the process of decalcification.

Question 5

All of the following statements are true about the factors that influence the rate of decalcification, except:
A)The rate of decalcification will depend upon the fixative used.
B)The rate of decalcification will depend upon the structure of the specimen.
C)The rate of decalcification will depend upon the volume and concentration of the solution used.
D)The rate of decalcification will depend upon temperature.

Accepted Answer

The rate of decalcification will depend upon the fixative used.
All of the statements above are true about the factors that influence the rate of decalcification such as the volume and concentration of the solution used, the structure of the specimen, and as well as by the temperature except for the fixative being used. The fixative used during fixation will not affect nor hasten decalcification process.

Question 6

Which of the following mineral acids is known to be the fastest acting decalcifying agent?
A)Hydrochloric acid
B)Formic acid
C)Nitric acid
D)Citric acid

Accepted Answer

Nitric acid
Nitric acid is the mineral acid that is known to be the fastest acting decalcifying agent. Nitric acid is a very fast and efficient decalcifying agent that produces minimal distortion and is therefore, recommended for routine purposes. All the other mineral acids in the choices are not as fast a decalcifying agent as nitric acid is.

Question 7

Which of the following acids is a moderate-acting decalcifying agent with less distortion of the sample tissue?
A)Citric acid
B)Formic acid
C)Hydrochloric acid
D)Trichloroacetic acid

Accepted Answer

Formic acid
Formic acid is the acid that is a moderate-acting decalcifying agent with less distortion of the sample tissue. Formic acid is the second fastest decalcifying agent that produces better nuclear staining with less distortion of the tissue compared to nitric acid. It is also recommended for routine decalcification of postmortem research tissue. All the other choices are not moderate acting acids and they do not lessen tissue distortion.

Question 8

These are substances which combine calcium ions and other salts to form weakly dissociated complexes and facilitate removal of calcium salt.
A)Acids
B)Ion exchange resins
C)Chelating agents
D)Electrophoresis

Accepted Answer

Chelating agents
The substances which combine calcium ions and other salts to form weakly dissociated complexes and facilitate removal of calcium salts are chelating agents. The most common chelating agent used is Ethylene Diamine Tetraacetic Acid (EDTA) salt. The other choices do not fit the definition and description of chelating agents.

Question 9

All of the following statements about ion exchange resins are correct, except:
A)The degree of decalcification can be measured by chemical means.
B)Cellular detail is well-preserved.
C)Decalcification is hastened.
D)Daily washing of solutions is eliminated.

Accepted Answer

The degree of decalcification can be measured by chemical means.
All of the following statements about ion exchange resins are correct, except for the statement that the degree of decalcification can be measured by chemical means. But rather, it is measured by physical means and through the X-ray method.

Question 10

Which of the following best describes the process used in decalcification whereby positively charged calcium ions are attracted to a negative electrode and subsequently removed from the decalcifying solution?
A)Acids
B)Ion exchange
C)Chelation
D)Electrophoresis

Accepted Answer

Electrophoresis
The method that best describes the process used in decalcification whereby positively charged Calcium ions are attracted to a negative electrode and subsequently removed from the decalcifying solution is Electrophoresis. The principle applied in electrophoresis is similar to chelation but differs mainly in the utilization of electricity. All the other choices do not accurately fit the description of electrophoresis.

Question 11

The following statements describe an ideal dehydrating solution, except:
A)It must dehydrate rapidly without producing considerable shrinkage or distortion of tissues.
B)It should evaporate very fast
C)It should not harden the tissues excessively
D)It should not remove stains

Accepted Answer

It should evaporate very fast
The following statements describe an ideal dehydrating solution, except for the statement that it should evaporate very fast. A dehydrating solution must not evaporate very fast for it will cause tissue shrinkage.

Question 12

Which of the following choices is an excellent dehydrating agent?
A)Dioxane
B)Triethyl Phosphate
C)Ethyl alcohol
D)Acetone

Accepted Answer

Dioxane
Dioxane is an excellent dehydrating agent. Dioxane is an excellent clearing agent as well. This is because this agent is readily miscible in water, in melted paraffin, in alcohol, and in xylol. The other agents are not excellent choices as dehydrating agents.

Question 13

What clearing agent should be used when the tissue is to be cleared directly from water, as in a frozen section?
A)Xylene
B)Cedarwood
C)Glycerine
D)Dioxane

Accepted Answer

Glycerine
The clearing agent that should be used when the tissue is to be cleared directly from water, as in a frozen section is glycerine. No de-alcoholization is involved in this process. All the other options are not to be used in such method stated above.

Question 14

All of the following statements are true about the ideal characteristics of a clearing agent, except:
A)It should make tissues transparent.
B)It should not dissolve out Aniline dyes
C)It should not evaporate quickly in a water bath.
D)It should be miscible with water to promote the rapid removal of the dehydrating agent.

Accepted Answer

It should be miscible with water to promote the rapid removal of the dehydrating agent.
All of the following statements are true about the ideal characteristics of a clearing agent except for the statement that it should be miscible with water to promote the rapid removal of the dehydrating agent. It is because an ideal clearing agent should be miscible with alcohol and not with water. What we are removing is a dehydrating agent and the dehydrating agent in turn, removes water.

Question 15

What clearing agent is commonly used for both embedding and mounting procedures?
A)Xylene
B)Carbon tetrachloride
C)Clove oil
D)Aniline oil

Accepted Answer

Xylene
Xylene is the clearing agent that is commonly used for both embedding and mounting procedures. Xylene is a colorless agent that is commonly used today because of its ability to clear dehydrating agents, as well as it is utilized for embedding and mounting procedures. The other agents do not have this dual property.

Question 16

Which of the following agent is recommended for central nervous system tissues and other cytological studies?
A)Chloroform
B)Benzene
C)Cedarwood oil
D)Clove oil

Accepted Answer

Cedarwood oil
The clearing agent that is recommended for use on central nervous system tissues and other cytological studies is the Cedarwood oil. This is due to the fact that central nervous system tissues and other smooth muscles are very delicate and can easily be distorted. Thus, the recommended clearing agent to be used must not cause distortion of the tissue sample. All other options are not the choice for use on central nervous tissues and other cytological studies.

Question 17

This type of clearing agent rapidly clears tissues but it is extremely toxic to man and may be carcinogenic. What clearing agent is this?
A)Toluene
B)Benzene
C)Xylene
D)Chloroform

Accepted Answer

Benzene
The type of clearing agent that rapidly clears tissue but is extremely toxic to man and may be carcinogenic is Benzene. Despite its numerous advantages as a clearing agent, excessive exposure to benzene may damage the user's bone marrow and later may cause aplastic anemia.

Question 18

This clearing agent is commonly used as a substitute for Xylene and Benzene.
A)Toluene
B)Cedarwood oil
C)Tetrahydrofuran
D)Clove oil

Accepted Answer

Toluene
Toluene is the clearing agent that is commonly used as a substitute for Xylene and Benzene. Toluene can act as a clearing agent both during embedding and mounting processes, thus it can act as a substitute to both agents stated above. Other agents are not able to substitute for xylene and benzene.

Question 19

All of the following statements are true about clearing agents, except:
A)Removal of the fixative from tissue.
B)Removal of alcohol from the tissue.
C)Improve refractive index.
D)Both A and C

Accepted Answer

Removal of fixative in the tissue.
The following statements are true about clearing agents, except for the removal of the fixative form the tissue. Fixatives are removed with dehydrating agents and not by clearing agents.

Question 20

This is the process whereby the clearing agent is completely removed from the tissue and is replaced by a medium that will completely fill all the tissue cavities.
A)Embedding
B)Impregnation
C)Mounting
D)Sectioning

Accepted Answer

Impregnation
Impregnation is the process whereby the clearing agent is completely removed from the tissue and is replaced by a medium that will completely fill all the tissue cavities. Impregnation will give a firm consistency to the specimen and allowing easier handling and cutting of tissues without any damage. All the other terms in the choices do not accurately fit the definition of impregnation.

Quiz 4: Processing and Embedding

What is the usual range of temperature of a water bath that removes the paraffin wax from the tissue?

The paraffin oven is maintained at what temperature?

This is the procedure whereby lime salts are removed from the tissues following after fixation.

Calcium and other calcified materials may be removed from the tissue by any of the following agents, except:

All of the following statements are true about the factors that influence the rate of decalcification, except:

Which of the following mineral acids is known to be the fastest acting decalcifying agent?

Which of the following acids is a moderate-acting decalcifying agent with less distortion of the sample tissue?

These are substances which combine calcium ions and other salts to form weakly dissociated complexes and facilitate removal of calcium salt.

All of the following statements about ion exchange resins are correct, except:

Which of the following best describes the process used in decalcification whereby positively charged calcium ions are attracted to a negative electrode and subsequently removed from the decalcifying solution?

The following statements describe an ideal dehydrating solution, except:

Which of the following choices is an excellent dehydrating agent?

What clearing agent should be used when the tissue is to be cleared directly from water, as in a frozen section?

All of the following statements are true about the ideal characteristics of a clearing agent, except:

What clearing agent is commonly used for both embedding and mounting procedures?

Which of the following agent is recommended for central nervous system tissues and other cytological studies?

This type of clearing agent rapidly clears tissues but it is extremely toxic to man and may be carcinogenic. What clearing agent is this?

This clearing agent is commonly used as a substitute for Xylene and Benzene.

All of the following statements are true about clearing agents, except:

This is the process whereby the clearing agent is completely removed from the tissue and is replaced by a medium that will completely fill all the tissue cavities.