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Questions and Answers
What is the main focus of histopathology?
What is the main focus of histopathology?
Which type of specimen has the shortest retention period in record keeping?
Which type of specimen has the shortest retention period in record keeping?
What is the thickness range for sectioning in histological preparation?
What is the thickness range for sectioning in histological preparation?
Which category of cytology involves cells that have been shed from epithelial surfaces?
Which category of cytology involves cells that have been shed from epithelial surfaces?
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Which method of tissue preparation is typically used for organisms?
Which method of tissue preparation is typically used for organisms?
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What is the purpose of teasing or dissociation in fresh tissue examinations?
What is the purpose of teasing or dissociation in fresh tissue examinations?
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What type of specimen is typically associated with exfoliative cytology?
What type of specimen is typically associated with exfoliative cytology?
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What is a disadvantage of the teasing/dissociation method in tissue examination?
What is a disadvantage of the teasing/dissociation method in tissue examination?
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What is the purpose of using microincineration in tissue processing?
What is the purpose of using microincineration in tissue processing?
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What thickness is generally required for whole mount preparations?
What thickness is generally required for whole mount preparations?
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In the given formula V1C1 = V2C2, what does C1 represent?
In the given formula V1C1 = V2C2, what does C1 represent?
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Which technique involves using radioactive isotopes to determine tissue relationships?
Which technique involves using radioactive isotopes to determine tissue relationships?
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What is the primary principle behind microwave processing in tissue preparation?
What is the primary principle behind microwave processing in tissue preparation?
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When preparing a solution to achieve a concentration of 25 mg/mL from a 100 mg/mL stock solution, what volume of the stock solution is needed?
When preparing a solution to achieve a concentration of 25 mg/mL from a 100 mg/mL stock solution, what volume of the stock solution is needed?
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What is a common use for enzyme histochemistry in tissue preparation?
What is a common use for enzyme histochemistry in tissue preparation?
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Why is a polarizing microscope used in the context of microincineration?
Why is a polarizing microscope used in the context of microincineration?
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What is the main role of specialized silver stains in histological preparations?
What is the main role of specialized silver stains in histological preparations?
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What stage follows after fixing in the steps of manual tissue processing?
What stage follows after fixing in the steps of manual tissue processing?
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What is the primary purpose of the fixation process in tissue preservation?
What is the primary purpose of the fixation process in tissue preservation?
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Which of the following fixatives is used for electron microscopy?
Which of the following fixatives is used for electron microscopy?
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How does fixation influence protein structure?
How does fixation influence protein structure?
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What pH range is optimal for tissue fixation?
What pH range is optimal for tissue fixation?
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What effect does fixation have on soft tissues?
What effect does fixation have on soft tissues?
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Which factor greatly influences staining after fixation?
Which factor greatly influences staining after fixation?
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What is the impact of fixation on bacterial decomposition?
What is the impact of fixation on bacterial decomposition?
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At what temperature range should fixation ideally occur?
At what temperature range should fixation ideally occur?
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What type of necrosis is characterized by the complete destruction of the cell due to enzymatic dissolution?
What type of necrosis is characterized by the complete destruction of the cell due to enzymatic dissolution?
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Which type of necrosis involves the destruction of adipose tissue, often associated with pancreatic degeneration?
Which type of necrosis involves the destruction of adipose tissue, often associated with pancreatic degeneration?
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Gangrene is primarily caused by which combination of factors?
Gangrene is primarily caused by which combination of factors?
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What is the result of dry gangrene in terms of tissue appearance?
What is the result of dry gangrene in terms of tissue appearance?
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Which of the following diseases is associated with caseous necrosis?
Which of the following diseases is associated with caseous necrosis?
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Who is recognized as the Father of Medicine?
Who is recognized as the Father of Medicine?
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What does the Medical Technologists' Prayer emphasize in relation to caring for the sick?
What does the Medical Technologists' Prayer emphasize in relation to caring for the sick?
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Which type of necrosis is specifically related to bacterial infection following ischemic injury?
Which type of necrosis is specifically related to bacterial infection following ischemic injury?
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What is the primary advantage of using a 2.5% fixative for small tissue fragments?
What is the primary advantage of using a 2.5% fixative for small tissue fragments?
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Why is mercuric chloride considered a common fixative?
Why is mercuric chloride considered a common fixative?
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What happens to the tissues when glacial acetic acid is used as a fixative?
What happens to the tissues when glacial acetic acid is used as a fixative?
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What major disadvantage is associated with picric acid as a fixative?
What major disadvantage is associated with picric acid as a fixative?
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Which fixative is recommended for larger tissue samples?
Which fixative is recommended for larger tissue samples?
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What is a key feature of using osmium tetroxide as a fixative?
What is a key feature of using osmium tetroxide as a fixative?
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Acetone is especially suitable for fixing which type of tissue?
Acetone is especially suitable for fixing which type of tissue?
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Which of the following is a major disadvantage of using alcohol as a fixative?
Which of the following is a major disadvantage of using alcohol as a fixative?
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What property makes potassium dichromate a favorable fixative for certain types of tissues?
What property makes potassium dichromate a favorable fixative for certain types of tissues?
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What characteristic is associated with the use of formal saline fixative?
What characteristic is associated with the use of formal saline fixative?
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What is a common issue resulting from prolonged fixation with mercuric chloride?
What is a common issue resulting from prolonged fixation with mercuric chloride?
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What is a notable disadvantage of using heat as a fixation method?
What is a notable disadvantage of using heat as a fixation method?
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Which fixative is known for causing hemolysis of red blood cells?
Which fixative is known for causing hemolysis of red blood cells?
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Study Notes
Histopathology & Histotechniques
- Histopathology studies diseases in tissues and organs.
- Histotechniques prepare tissues for microscopic study, identifying them as malignant or benign.
Record Keeping & Specimen Retention
- Specimen retention: 1 month to 1 year.
- Tissue block retention: 3 to 10 years.
- Slides are kept indefinitely.
- Records and result forms are permanent. Result forms are kept in triplicate.
Types of Histological Preparation
- Whole mount: Used for organisms; 0.2-0.5 mm thickness.
- Sectioning: Most common preparation method; 3.0-5.0 mm thickness.
- Smearing: For blood, bone marrow, and bodily fluids; used in cytological examination.
Diagnostic & Exfoliative Cytology
- Diagnostic cytology: Microscopic cell examination for diagnosis.
- Exfoliative cytology: Microscopic study of cells shed from epithelial surfaces (e.g., ascitic fluid, CSF, urine, sputum). Includes epithelial and mucous membrane samples. Fine needle aspiration (FNAB) is a type of diagnostic cytology.
Fresh Tissue Examinations
- Teasing/Dissociation: Also known as dissection or separation. Uses normal saline solution (0.85-0.90% NaCl). Examined stained (bright field/light microscopy) or unstained (phase-contrast microscopy). Disadvantage: destroys anatomical relationships.
- Coagulation: Rapid cytoplasm coagulation by intracellular enzymes (e.g., anemic or ischemic infarction).
- Liquefaction/Colliquative: Rapid enzymatic cell dissolution (e.g., bacterial infection).
- Fat: Adipose tissue destruction (e.g., pancreatic degenerations).
- Caseous: Mixture of coagulated protein and fat (e.g., syphilis, tularemia, lymphogranuloma).
- Gangrenous: Massive tissue death from ischemia and bacterial infection (necrosis plus putrefaction).
Gangrene
- Massive tissue death from bacterial infection and anoxia.
- Dry gangrene: Caused by arterial occlusion; ischemic necrosis and mummification (e.g., arterial embolism).
- Wet gangrene: Caused by venous occlusion; bacterial infection supervenes on ischemic injury (e.g., toxemia, bacterial infection).
Historical Perspectives (Medical Technology)
- Hippocrates: Father of Medicine.
- Dr. Jesse Umali: First BSMT graduate.
- Mr. Crisanto Almario: Father of PAMET (Philippine Association of Medical Technologists).
Reagent Preparation
- Basic formula: V1C1 = V2C2. Example calculation provided in text showing preparation of a phenol solution.
Tissue Processing Steps (Manual)
- Fixation: Kills, hardens, and preserves tissue. Effects include protein denaturation, bacterial inhibition, tissue hardening, and improved optical differentiation. Uses neutral buffered formalin saline or formaldehyde. Electron microscopy uses conjugated fixatives (osmic acid and glutaraldehyde). Factors to consider: pH (6-8), temperature (room temperature, 45°C for RNA, 65°C for DNA), and slightly hypertonic osmolality.
Types of Fixatives (According to Composition)
- (Further details on types of fixatives are cut off in the provided text)
Metallic Fixatives: Mercuric Chloride
- Most common fixative; rapidly penetrates and hardens tissues.
- Excellent for nuclear detail and trichrome staining; choice for tissue photography.
- Causes shrinkage, RBC lysis, removes iron from hemosiderin; slow penetration (2-5mm thickness).
- Fine detail of nuclear components, greater affinity to acid dyes.
- Recommended for renal tissues, connective tissues, muscles, and fibrin.
- Forms black granular deposits in tissues; corrosive to metals; reduces glycogen.
Metallic Fixatives: Potassium Dichromate & Chromic Acid
- Potassium dichromate: 3% aqueous solution; preserves lipids and mitochondria (pH 4.5-5.2). Does not precipitate cytoplasmic structures; adequately preserves CHO.
- Chromic acid: 1-2% aqueous solution; precipitates all proteins; strong oxidizing agent.
Lead Fixative
- 4% aqueous solution; recommended for acid mucopolysaccharide; fixes connective tissue mucin.
- Forms insoluble lead carbonate on prolonged standing (removed by filtration or acetic acid).
Picric Acid
- Excellent and stable fixative for glycogen demonstration; penetrates well, fixes small tissues rapidly.
- Yellow stain prevents overlooking small fragments; allows brilliant trichrome staining.
- Causes RBC hemolysis; not suitable for frozen sections; prolonged fixation causes hardness.
- Picrates form upon protein (never wash in water before dehydration); produces excessive staining.
- Highly explosive when dry; dissolves and alters lipids; interferes with Azure Eosin staining.
Glacial Acetic Acid
- Used with other fixatives; fixes and precipitates nucleoproteins, chromosomes, and chromatin.
- Causes tissue swelling (collagen-containing substances); contraindicated for cytoplasmic fixation (destroys mitochondria and Golgi bodies).
- When combined with potassium dichromate, lipid-fixing properties are destroyed.
Acetone
- Used ice-cold (-5°C to 4°C); recommended for water-diffusible enzymes (phosphatases and lipases).
- Used for brain tissue and rabies diagnosis; dissolves fat; preserves glycogen poorly.
- Evaporates rapidly; used as a solvent for certain metallic salts (freeze substitution).
Alcohol Fixatives (Methanol & Ethanol)
- Rapidly denatures and precipitates proteins; both fixative and dehydrating agent.
- Methanol: excellent for dry and wet smears, blood, and bone marrow tissues; slow penetration; overhardening if fixed >48 hours.
- Ethanol (70-100%): preserves glycogen (but doesn't fix it), nucleoproteins, and nucleic acids. Lower concentrations cause RBC hemolysis and inadequate WBC preservation. Hemosiderin preservation is less than in buffered formaldehyde.
Osmium Tetroxide/Osmic Acid
- Pale yellow powder; strong oxidizing solution; precipitates and gels proteins.
- Preserves fats, lipids, cytoplasmic structures (Golgi bodies and mitochondria), myelin, and peripheral nerves.
- Used for ultrathin sectioning in electron microscopy (EM); expensive; poor penetration.
- Irritant to eyes; inhibits hematoxylin stain; extremely volatile.
Heat Fixation
- Thermal coagulation of tissue proteins; better fixation than chemical methods.
- Preserves both nuclear and cytoplasmic details; suitable for frozen tissue preparations and bacteriological smears.
- Causes considerable shrinkage and distortion; destroys RBCs; dissolves starch and glycogen.
Compound Micro-Fixatives: 10% Formal Saline
- Simple fixative; composition: saturated formaldehyde (40g by wt).
- Penetrates and fixes tissue evenly; preserves both microanatomical and histological detail.
- Slow fixative; tissue tends to shrink with alcohol dehydration.
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Description
This quiz covers essential concepts in histopathology and histotechniques, focusing on the preparation of tissues for microscopic study and the methods of specimen retention. It also explores the types of histological preparations and the different aspects of diagnostic and exfoliative cytology. Test your knowledge on these critical subjects in the field of pathology.