Chapter 9: Nerves Flashcards
Nissl substance is present in what kind of cell?
Neurons.
What kind of cells are neurons?
A nerve cell.
What is Nissl substance composed of?
Rough endoplasmic reticulum.
Nissl substance is demonstrated by which of the following methods?
The Cresyl Echt Violet.
Astrocytes are demonstrated by what stain?
The Cajal stain.
What is the preferred fixative for sections to be stained by the Cajal technique?
Formalin ammonium bromide.
Sections to be stained for myelin should be cut at:
10-15 microns to see the best posible contrast between gray and white matter.
In the Holzer technique, glial fibers are stained with:
A crystal violet solution.
A method that can be used to demonstrate senile plaques is the:
Bielschowsky, Sevier-munger and thioflavin S.
Where are neuron cell bodies commonly found?
The gray matter.
Spinal cord is an excellent control for what stain?
Weil.
What is the preferred fixative for the Bodian technique?
10% NBF.
Glial cells are stained blue by the:
phosphotungstic acid-hematoxylin.
Macroscopic evaluation (naked eye) can be used to judge the quality of what kind of neuron stain?
Weil and Luxol fast blue.
What are two techniques for demonstrating myelin?
Weil and Luxol fast blue.
What two solutions are used for differentiation in the Weil procedure?
Ferric ammonium sulfate and Borax ferricyanide.
What reagents are contained in the staining solution used in the Weil procedure?
Ferric ammonium sulfate and Hematoxylin.
What are two methods for demonstrating nerve cell processes?
Bodian, Holmes, Servier-munger and Bielschowsky.
Where is myelin found in the brain?
White.
What is myelin?
A fatty, non-living substance that is responsible for the color of white matter. It surrounds nerves and acts as an insultation.
T/F: Functionally, the autonomic nervous system is under voluntary control.
False, the autonomic NS is involuntary.
T/F: A nerve only has one axon.
True.
T/F: Nissl substance is composed of clumps of DNA.
False, it is composed of rough endoplasmic reticulum.
T/F: In the CNS, myelin is made by astrocytes.
False, it is made by oligodendroglia.
T/F: Ependymal cells are epithelial cells.
True.
T/F: Myelin is responsible for the color of white matter.
True.
T/F: Stains for Nissl substance can be used to identify the presence of neurons in tumor tissue.
True.
T/F: A colorless background indicates a problem with the cresyl echt violet stain.
False, this is what a good stain would look like.
T/F: Peripheral nerve would make a good control for a Bodian stain.
True.
T/F: Copper is used in the Bodian impregnating solution to increase the differentiation between neural and connective tissues.
True.
T/F: The Holmes technique is an argentaffin method.
False, the Holmes technique requires an external reducer so it is a argyrophil method.
T/F: Prolonged washing of sections stained with PTAH will enhance the red staining of certain tissue components.
False, it will wash them away.
T/F: The Weil technique uses both excess mordant and an oxidizer for the differentiation steps.
True.
T/F: Luxol fast blue is a water soluble dye.
False, it is alcohol soluble.
T/F: Gray matter is essentially colorless in a correctly performed Luxol fast blue stain.
True.
T/F: When used as a counterstain for Luxol fast blue, cresyl echt violet must be used in an acid solution.
True.
T/F: Then the Luxol fast blue is combined with the Holmes silver nitrate stain, both glial fibers and myelin are demonstrated.
False, only nerve fibers and myelin are demonstrated.
T/F: Aniline oil used in the Holzer technique is considered very toxic and is rated by NIOSH as neoplastic.
True.
What color are nerve fibers stained by the Bodian stain?
Black.
What is the preferred fixative for a section to be stained by the Bodian method?
10% NBF.
What is the impregnating solution used in the Bodian method?
Silver protein.
Bodian stained sections show marked precipitation. How could this have happened?
Chemically cleaned glassware was not used.
Bodian sections show light gray nerve fibers. What would be one possible explanation for this?
The sections were left too long in oxalic acid.
Sections stained with PTAH show blue glial fibers. One possible cause would be:
The sections were washed too long before clearing and mounting.
Sections stained using the Holer technique show marked purple crystalline precipitate. This could be removed by:
Treating with straight aniline oil.
Weil stained sections show blue-black gray matter and a lighter blue white matter. How did this happen?
It was overstained with hematoxylin and should be differentiated until the gray matter is a light tan.
Luxol fast blue stained sections show dark blue gray matter and a lighter blue white matter. How can this be corrected?
Continuing the differentiation step.
Sections stained with the Luxol fast blue-cresyl echt violet technique show bluish purple myelin and a diffuse rose-purple background. What happened?
The cresyl echt violet was not properly acidified.
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:
The sections were cut too thin.
What is an example of an exogenous pigment?
Carbon.
