Intro to Histology Flashcards
What is the difference between Histology and pathology ?
Histology is the microscopic study of normal cells and tissues while, Pathology is the microscopic study of diseased cells and tissues.
What are the 4 main tissue types?
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
What are the main differences between LM and EM?
Light microscopes reveal basic cellular structure its resolution is 0.2 μM
Electron microscopes can reveal ultrastructure its resolution is 1 nm (200- fold greater)
Arrange the steps for preparing a tissue sample
Viewing
Embedding
Sectioning
Fixation
Staining
Specimen collection
Dehydration
Specimen collection
Fixation
Dehydration
Embedding
Sectioning
Staining
Viewing
What type of obtaing biopsy is used for skin and oral surface?
incision or punch biopsy
Fixation
- Preserves structural arrangement between cells & ECM
- Terminates all biochemical reactions
- Prevents tissue decomposition
- Formaldehyde & Glutaraldehyde (Examples of fixatives)
What the commonly use in fixation step?
Formaldehyde and glutaraldehyde.
In Embedding step alcohol will replace by?
xylene
Sectioning step
- Sectioned using Microtome
- Thin, flat, single layer of cells sectioned (7um thick)
- Mounted onto glass slides
What are the differences between Haematoxylin and Eosin stain?
Haematoxylin is basic → stains acidic structures blue/purple (Nucleic acids)
Eosin is acidic → stains basic structures red/pink (Cytoplasm)
Periodic acid-schiff reaction (PAS) stain what?
Stains complex carbohydrates magenta
PAS-Positive → Mucins, brush borders, basement membranes
What Masson Trichrome stain and what colour will appear?
Stains connective tissues
-Nuclei & basophilic structures - blue/purple
-Collagen - green/blue
-Cytoplasm, muscle, RBC, keratin - red
What Immunohistochemistry is used for?
Utilises antibody specificity for antigen
Mention other staining protocols
Alcian Blue
– Stains mucin and cartilage blue
van Gieson
– Stains collagen red
– stains nuclei, erythrocytes and cytoplasm yellow
Reticulin stain
– Stains reticulin fibres blue/black
Which process prevents decomposition of the specimen?
Fixation
Which is the most commonly used stain for light microscopy?
H&E
Which staining technique uses antibodies to bind specific components?
Immunohistochemistry
Which of the following statements is true of electron microscopy?
a.Routinely used for diagnostic histopathology
b.Reveals basic cellular structure
c.Is compatible with stains
d.Reveals ultrastructure of cells
d. Reveals ultrastructure of cells
Which description best matches each of these micrographs?
Light microscopy
Electron micrograph
Which type of microscopy provides the greatest field of view?
Light microscopy
A patient comes into your clinic with a suspicious lesion on the floor of their mouth. You refer them to the histopathology unit for a biopsy. What type of biopsy will most likely be taken by the clinician in the histopathology unit?
punch biopsy
Why is it important for biopsy tissue to undergo fixation? Select all that apply
a.Prevents tissue decomposition
b.Allow embedding matrix to penetrate cells
c.Preserves the structural arrangement of the tissue
d.Terminates all biochemical reactions
a.Prevents tissue decomposition
c.Preserves the structural arrangement of the tissue
d.Terminates all biochemical reactions
Why is it important for biopsy tissue to be dehydrated through a graded series of alcohols and then immersed in xylene?
a.Water is incompatible with embedding matrices
b.Water is incompatible with staining
c.To prevent tissue decomposition
d.To enable thin sections to be cut
a.Water is incompatible with embedding matrices
Which of the following is the most commonly used staining technique?
a.Masson Trichrome
b.Periodic acid-Shiff
c.Immunohistochemistry
d.Haematoxylin and eosin
d.Haematoxylin and eosin
Which staining technique can be used to reveal information about the functional properties of cells?
a.Masson Trichrome
b.Periodic acid-Shiff
c.Immunohistochemistry
d.Haematoxylin and eosin
c.Immunohistochemistry
