Histology Flashcards
Resolution
the smallest distance at which two points can be distinguished from each other.
Resolution of the - Human eye - Bright-Field Microscope - TEM
-Human eye: 0.2 mm • Bright-field microscope: 0.2 µm • TEM: 2-3 nm
TEM allows to examine internal cellular structure
Electron-dense Electron-lucent
what region is shown by the colored dots?
TEM terms: Electron-dense (red), Electron-lucent (purple)
What is indicated by the blue arrow
BASIC stains, e.g. hematoxylin (blue), interact with acidic cellular components (basophilic, e.g. nucleic acids)
What is indicated by the red arrow
ACIDIC stains, e.g. eosin (pink), interact with basic cellular components (acidophilic, e.g. cytoplasm)
Name the steps in the preparation of tissue
- Fixation chemical physical
- Dehydration water→ethanol →xylene
- Embedding paraffin
- Sectioning
This picture is an example of what type of staining
Acidic components:
- Stain with basic dyes (e.g. hematoxylin)
- They are “basophilic” (typically blue)
- Examples: Nucleic acids (DNA & RNA) Dye+Nucleic acid
This picture is an example of what type of staining
Basic components:
- Stain with acidic dyes (e.g. eosin)
- They are “acidophilic” (typically pink/red)
- Examples: Cytoplasm Collagen fibers Examples of cell/tissue staining Collagen+Dye
What is this and what cell components does it stain
Hematoxylin
Stains basophilic cell components
Negatively charged anionic tissue - RNA+DNA (Acidic)
What is this and what cell components does it stain
Eosin
Stains acidophilic cell components - positively charged
Basic strcutures - like cytoplasm and collagen fibers
What stains are included in this pic
Hematoxylin and Eosin
What is this stain and what is it used for
Orcein – elastic fibers
What is this stain and what is it used for
Sudan black, osmium tetroxide - lipids
What is this stain and what is it used for
Silver stainreticular fibers
Name this stain and what its used for
PAS (Periodic Acid – Schiff) – carbohydrates
Name this stain and what its used for
Immunocytochemistry – specific Antibody-based interactions
Name the stain and what its used for
Trichrome stains – collagen fibers (blue or green)
Freeze fracture & freeze etch is used for what
SEM & TEM
What does this picture represent and what is its stain
Mucus, PAS stain
What does this picture represent and what is its stain
Lipids
Sudan black
What is represented in this picture
Red blood cell (RBC or erythrocyte) can be used as a “biological yardstick”. RBC’s diameter is 7-8 µm.
What is represented in this picture
Artificial spaces between the cells (tissue shrinkage).
What is represented in this picture
“Empty cells” due to the loss of substances.
What is represented in this picture
Wrinkles in the sectioned tissue
What type of tissue is this and in what part of the body is it located
Epithelial cells in the kidney
What type of tissue is this and in what part of the body is it located
Dorsal root ganglion cells
What type of tissue is this and in what part of the body is it located
Smooth muscle cells of the small intestine
What structures are represented in this picture
Electron micrograph of a plasma membrane (plasmalemma) that surrounds the cell
It contains phospholipids, cholesterol and proteins