Introduction Flashcards
What are the four basic types of tissues?
Epithelial
Connective
Muscular
Nervous
What is the difference between the parenchyma tissue of an organ vs the stroma tissue?
Parenchyma - performs the the functions of the organ
Stroma - the supportive framework of the organ
What are the three priciples of the cell theory?
- All living organisms are composed of cells
- Cells are the basic structural and functional units of life
- Cells arise from pre-existing cells by division
What is the most common type of microscopy for studying tissues and cells?
Light microscopy
Describe the paraffin wax technique for light microscopy specimen.
- cut to appropriate size.
- Fixate the tissue using neutral buffered formalin
- Dehydrate using increasing concentrations of ethanol
- Clear tissue of alcohol, usually with xylene because it is miscible with alcohol and paraffin
- Infiltrate and embed by placing in mold of paraffin wax, then rapidly cool with cold water
- Trim and perform sections with rotary microtome
- float in warm water bath an then place on glass slide to dry
- Remove excess wax with xylene and rehydrate with decreasing concentrations of ethanol
- Stain with whatever stain you want
- Dehydrate again using increasing concentrations of alcohol and then clear again with xylene, use adhesive to secure coverslip
What does a basic dyes tend to have an affinity for?
Things with a net negative charge:
DNA
RNA
What do acidic dyes (acidophilic) have an affinity for?
Cell components with a net positive charge (acidophilic):
What stain is this? What is significant about this stain?
Hematoxylin and Eosin (H&E)
THIS IS THE MOST COMMON STAIN USED
Hematoxylin is basic: nuclei stains purple
Eosin is acidic: collagen and muscle stains pink
What types of stains are these? What do they primarily target?
These are elastic stains, the one on the right is specifically called Van Giesons stain for elastic fibers
Good at targeting elastic fibers, they stain a dark blue/black as well as the nuclei
What type of stains are these? What are they particularly useful for?
These are silver stains, the one on the right is specifically Bielschowskys silver stain
These are good for staining reticular fibers (black) and nerve processes (black)
Nucleoli stain black and cytoplasm stains slightly red as well
What stains are these? Why is it called this?
Trichrome stain (Mallories bottom left, Massons top and bottom right)
Named that way because it consists of three colors
Collagen of connective tissue is blue/green
Nuclei are black
Muscle is red
Cytoplasm of nonmuscle cells is pink/red
What type of stain is this? What gets highlighted in this stain?
Periodic Acid-Schiff (PAS) Reaction
Stains granules of goblet cells a purple/magenta color
Basement membranes are stained pink/red
Glycogen granules stain red/magenta
What type of stain is this? What is commonly stained this way?
Wrights stain
Blood: RBCs stain pink, Nuclei of white blood cells stain dark blue/black
What type of stain is this? What does it primarily stain?
This is an Osmium tetroxide (osmic acid) stain
Stains lipids black so adipose cells and myelin sheat gets stained well
What is the basic components of an electron microscope?
Electron gun: emits electron into a vacuum tube by heating cathode filament
Condenser: focuses electrom beam onto an object
Name each plane and each section
Longitudinal plane (a,b)
= Longitudinal section
Transverse plane (d,e)
= Cross section
Tangential plane (c,f)
Name each plane
Longitudinal plane (a)
Transverse plane (d,e,f)
Oblique plane (c)
Tangential plane (b)
