Chapter 9: Nerves

Question 1

Nissl substance is present in what kind of cell?

Answer 1

Neurons.

Question 2

What kind of cells are neurons?

Answer 2

A nerve cell.

Question 3

What is Nissl substance composed of?

Answer 3

Rough endoplasmic reticulum.

Question 4

Nissl substance is demonstrated by which of the following methods?

Answer 4

The Cresyl Echt Violet.

Question 5

Astrocytes are demonstrated by what stain?

Answer 5

The Cajal stain.

Question 6

What is the preferred fixative for sections to be stained by the Cajal technique?

Answer 6

Formalin ammonium bromide.

Question 7

Sections to be stained for myelin should be cut at:

Answer 7

10-15 microns to see the best posible contrast between gray and white matter.

Question 8

In the Holzer technique, glial fibers are stained with:

Answer 8

A crystal violet solution.

Question 9

A method that can be used to demonstrate senile plaques is the:

Answer 9

Bielschowsky, Sevier-munger and thioflavin S.

Question 10

Where are neuron cell bodies commonly found?

Answer 10

The gray matter.

Question 11

Spinal cord is an excellent control for what stain?

Answer 11

Weil.

Question 12

What is the preferred fixative for the Bodian technique?

Answer 12

10% NBF.

Question 13

Glial cells are stained blue by the:

Answer 13

phosphotungstic acid-hematoxylin.

Question 14

Macroscopic evaluation (naked eye) can be used to judge the quality of what kind of neuron stain?

Answer 14

Weil and Luxol fast blue.

Question 15

What are two techniques for demonstrating myelin?

Answer 15

Weil and Luxol fast blue.

Question 16

What two solutions are used for differentiation in the Weil procedure?

Answer 16

Ferric ammonium sulfate and Borax ferricyanide.

Question 17

What reagents are contained in the staining solution used in the Weil procedure?

Answer 17

Ferric ammonium sulfate and Hematoxylin.

Question 18

What are two methods for demonstrating nerve cell processes?

Answer 18

Bodian, Holmes, Servier-munger and Bielschowsky.

Question 19

Where is myelin found in the brain?

Answer 19

White.

Question 20

What is myelin?

Answer 20

A fatty, non-living substance that is responsible for the color of white matter. It surrounds nerves and acts as an insultation.

Question 21

T/F: Functionally, the autonomic nervous system is under voluntary control.

Answer 21

False, the autonomic NS is involuntary.

Question 22

T/F: A nerve only has one axon.

Answer 22

True.

Question 23

T/F: Nissl substance is composed of clumps of DNA.

Answer 23

False, it is composed of rough endoplasmic reticulum.

Question 24

T/F: In the CNS, myelin is made by astrocytes.

Answer 24

False, it is made by oligodendroglia.

Question 25

T/F: Ependymal cells are epithelial cells.

Answer 25

True.

Question 26

T/F: Myelin is responsible for the color of white matter.

Answer 26

True.

Question 27

T/F: Stains for Nissl substance can be used to identify the presence of neurons in tumor tissue.

Answer 27

True.

Question 28

T/F: A colorless background indicates a problem with the cresyl echt violet stain.

Answer 28

False, this is what a good stain would look like.

Question 29

T/F: Peripheral nerve would make a good control for a Bodian stain.

Answer 29

True.

Question 30

T/F: Copper is used in the Bodian impregnating solution to increase the differentiation between neural and connective tissues.

Answer 30

True.

Question 31

T/F: The Holmes technique is an argentaffin method.

Answer 31

False, the Holmes technique requires an external reducer so it is a argyrophil method.

Question 32

T/F: Prolonged washing of sections stained with PTAH will enhance the red staining of certain tissue components.

Answer 32

False, it will wash them away.

Question 33

T/F: The Weil technique uses both excess mordant and an oxidizer for the differentiation steps.

Answer 33

True.

Question 34

T/F: Luxol fast blue is a water soluble dye.

Answer 34

False, it is alcohol soluble.

Question 35

T/F: Gray matter is essentially colorless in a correctly performed Luxol fast blue stain.

Answer 35

True.

Question 36

T/F: When used as a counterstain for Luxol fast blue, cresyl echt violet must be used in an acid solution.

Answer 36

True.

Question 37

T/F: Then the Luxol fast blue is combined with the Holmes silver nitrate stain, both glial fibers and myelin are demonstrated.

Answer 37

False, only nerve fibers and myelin are demonstrated.

Question 38

T/F: Aniline oil used in the Holzer technique is considered very toxic and is rated by NIOSH as neoplastic.

Answer 38

True.

Question 39

What color are nerve fibers stained by the Bodian stain?

Answer 39

Black.

Question 40

What is the preferred fixative for a section to be stained by the Bodian method?

Answer 40

10% NBF.

Question 41

What is the impregnating solution used in the Bodian method?

Answer 41

Silver protein.

Question 42

Bodian stained sections show marked precipitation. How could this have happened?

Answer 42

Chemically cleaned glassware was not used.

Question 43

Bodian sections show light gray nerve fibers. What would be one possible explanation for this?

Answer 43

The sections were left too long in oxalic acid.

Question 44

Sections stained with PTAH show blue glial fibers. One possible cause would be:

Answer 44

The sections were washed too long before clearing and mounting.

Question 45

Sections stained using the Holer technique show marked purple crystalline precipitate. This could be removed by:

Answer 45

Treating with straight aniline oil.

Question 46

Weil stained sections show blue-black gray matter and a lighter blue white matter. How did this happen?

Answer 46

It was overstained with hematoxylin and should be differentiated until the gray matter is a light tan.

Question 47

Luxol fast blue stained sections show dark blue gray matter and a lighter blue white matter. How can this be corrected?

Answer 47

Continuing the differentiation step.

Question 48

Sections stained with the Luxol fast blue-cresyl echt violet technique show bluish purple myelin and a diffuse rose-purple background. What happened?

Answer 48

The cresyl echt violet was not properly acidified.

Question 49

Sections stained with the Luxol fast blue-Holmes silver nitrate technique show very pale blue myelin and gray axons. The most likely explanation would be:

Answer 49

The sections were cut too thin.

Question 50

What is an example of an exogenous pigment?

Answer 50

Carbon.