Podcast
Questions and Answers
What is the primary purpose of fixing a specimen in tissue preparation?
What is the primary purpose of fixing a specimen in tissue preparation?
- To preserve the cells in a life-like state (correct)
- To enhance the visibility of the tissue under an electron microscope
- To ensure the specimen is transparent enough for light microscopy
- To make the specimen easier to stain
Which characteristic must a specimen possess for successful examination using light microscopy?
Which characteristic must a specimen possess for successful examination using light microscopy?
- It must be opaque to reduce light scattering
- It must be thin and flat with a single layer of cells (correct)
- It must be preserved with a high concentration of alcohol
- It must be covered with a thick layer of dye
What is the first step in the paraffin embedded section preparation technique for soft tissues?
What is the first step in the paraffin embedded section preparation technique for soft tissues?
- Mounting the cut sections
- Processing of the tissue
- Embedding the tissue
- Fixation of the specimen (correct)
What type of microscopy would typically be used for examining thick tissues?
What type of microscopy would typically be used for examining thick tissues?
What role does staining play in the preparation of specimens for light microscopy?
What role does staining play in the preparation of specimens for light microscopy?
Which of the following techniques is NOT used for examining soft tissues?
Which of the following techniques is NOT used for examining soft tissues?
What is the main characteristic of a decalcified section preparation technique?
What is the main characteristic of a decalcified section preparation technique?
Under a light microscope, the process that allows tissues to be adequately observed involves which of the following?
Under a light microscope, the process that allows tissues to be adequately observed involves which of the following?
What happens to enamel during the decalcification process?
What happens to enamel during the decalcification process?
What is the primary purpose of grinding calci fied tissue specimens?
What is the primary purpose of grinding calci fied tissue specimens?
Which method is used for examining soft tissue specimens immediately?
Which method is used for examining soft tissue specimens immediately?
What is the purpose of the microtome in sectioning specimens?
What is the purpose of the microtome in sectioning specimens?
During the decalcification process, which component primarily remains after the inorganic substance is dissolved?
During the decalcification process, which component primarily remains after the inorganic substance is dissolved?
Which of the following statements about the frozen section technique is NOT correct?
Which of the following statements about the frozen section technique is NOT correct?
What is the first step in staining a section?
What is the first step in staining a section?
Which dye is referred to as a basophilic stain?
Which dye is referred to as a basophilic stain?
What color does eosin stain the basic components of the cells?
What color does eosin stain the basic components of the cells?
Which component is stained by hematoxylin?
Which component is stained by hematoxylin?
In histology, what is the term used to describe components that are stained by eosin?
In histology, what is the term used to describe components that are stained by eosin?
What is the typical thickness of tissue sections cut with a microtome?
What is the typical thickness of tissue sections cut with a microtome?
What happens to the sections after they are placed on glass slides before staining?
What happens to the sections after they are placed on glass slides before staining?
What is the primary purpose of dehydration in tissue processing?
What is the primary purpose of dehydration in tissue processing?
Which of the following is NOT a commonly used dehydrating agent?
Which of the following is NOT a commonly used dehydrating agent?
What is the role of xylene in the tissue processing procedure?
What is the role of xylene in the tissue processing procedure?
At what temperature is paraf n wax typically melted during the infiltration process?
At what temperature is paraf n wax typically melted during the infiltration process?
What is the main purpose of the embedding process in tissue preparation?
What is the main purpose of the embedding process in tissue preparation?
What characteristic of xylene makes it suitable for use after dehydration?
What characteristic of xylene makes it suitable for use after dehydration?
Why is it important for the specimen to be completely infiltrated with paraf n before embedding?
Why is it important for the specimen to be completely infiltrated with paraf n before embedding?
Which of these statements about the dehydration process is true?
Which of these statements about the dehydration process is true?
What is the primary aim of fixation in tissue processing?
What is the primary aim of fixation in tissue processing?
Which of the following agents is commonly used for light microscopic examination?
Which of the following agents is commonly used for light microscopic examination?
What happens if the concentration of formalin used in fixation is lower than 10%?
What happens if the concentration of formalin used in fixation is lower than 10%?
How does formalin stabilize tissue during the fixation process?
How does formalin stabilize tissue during the fixation process?
What factors can affect the fixation process?
What factors can affect the fixation process?
What is a consequence of using a fixative concentration higher than 10%?
What is a consequence of using a fixative concentration higher than 10%?
What is considered the ideal condition of tissue following fixation?
What is considered the ideal condition of tissue following fixation?
In the fixation process, what is the first step after transporting the organ to the laboratory?
In the fixation process, what is the first step after transporting the organ to the laboratory?
Flashcards are hidden until you start studying
Study Notes
Introduction to Oral Tissue Morphology
- Microscopic examination of tissue sections is crucial for understanding oral tissue morphology.
- Knowledge of microscopy types and histological techniques is essential for studying structure and function of oral tissues.
Types of Microscopy
- Light microscopes and electron microscopes are primary tools for tissue study.
- Light microscopy requires thin, translucent tissue sections mounted on glass slides for examination.
Requirements for Light Microscopy Specimens
- Cells must be preserved in a "life-like" state through fixation.
- Specimens should be transparent to allow light passage.
- Specimens must be thin and flat to ensure a single layer of cells.
- Staining is necessary for distinguishing different tissue components.
Specimen Preparation Techniques for Oral Tissue
- Four common techniques for preparing tissues for light microscopy:
- Paraffin embedded sections for soft tissues.
- Decalcified sections for hard tissues.
- Ground sections for calcified tissues.
- Frozen sections for soft tissues.
Paraffin Embedded Sections
- Most common method used for soft tissues (e.g., gingiva, tongue, salivary glands).
- Involves steps:
- Fixation of specimen.
- Tissue processing.
- Embedding in paraffin.
- Sectioning.
- Mounting cut sections.
- Staining.
Fixation of Specimen
- Fixation prevents autolysis and bacterial damage, preserves volume and shape, and facilitates clear staining.
- Common fixatives: 10% neutral formalin and Bouin’s fluid.
- Proper fixation is influenced by pH, temperature, and penetration of the fixative.
Processing of Tissue (Dehydration, Clearing, Infiltration)
- Dehydration: Replace fixative with dehydrating agents (e.g., alcohol, acetone) to ensure tissue compatibility with paraffin.
- Clearing: Transition from alcohol to xylene to make tissue transparent, as xylene is miscible with both.
- Infiltration: Use melted paraffin wax to thoroughly saturate the specimen, allowing for better cell distinction.
Embedding Process
- Tissue is surrounded by paraffin wax, which solidifies to provide support during sectioning.
Sectioning of Specimen
- Paraffin blocks are sliced with a microtome into thin sections (usually 4-10 microns).
- Sections are placed on cooled glass slides and stained with specific dyes.
Mounting and Staining
- Sections are mounted on adhesive-coated slides and allowed to dry before staining.
- Hematoxylin (blue for acidic components) and eosin (pink for basic components) are common stains used in histology.
Comparison of Hematoxylin and Eosin
- Hematoxylin:
- Nature: Base
- Stains acidic components (DNA, RNA) blue (basophilic).
- Eosin:
- Nature: Acid
- Stains basic components pink (acidophilic).
Decalcified Sections
- Used for examining hard tissues that have been demineralized to preserve structure (e.g., bone, teeth).
Ground Sections
- For calcified tissues, specimens may be ground to thin sections while preserving the organic matrix post-burn.
Frozen Sections
- Employed to analyze pathological tissue specimens immediately or when embedding reagents would alter tissue characteristics.
- Sections are cut using a freezing microtome (cryostat) without embedding.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
