histology Flashcards
Whats the purpose of ECM?
Extracellular matrix- transport nutrient, carry away catabolite and support cell
What are the methods of preparing tissue?
1- fixation
2- embedding/sectioning
3- staining
4- microscope
Whats the purpose of fixation?
Avoid tissue digestion
How does fixation take place?
- Cut tissue
- immerse tissue in solution with fixative
- fixative diffuse in it= better tissue preservation
What is an example of fixative?
Formalin
Whats the purpose of intravascular perfusion?
Better fixation
Whats the purpose of embedding?
To section it easily
Whats the material needed for embedding
Parafin (light microscope) and plastic resins (light + electron microscopy)
Whats the process that takes place in embedding/sectioning?
Dehydration:
-water + ethanol mixture- takes away water from tissue
-alcohol + embedding substance
Clearing:
-Add tissue in paraffin (60 degrees celcius)
-Add tissue in paraffin in normal temperature
Whats the purpose of staining?
Colorize cell- tissue act as acid + bases
What do DNA react with in staining and whats the color?
Base (hematoxylin) reacts with acid (DNA)- color: purple
What do collagen react with in staining and whats the color?
acid (eosin) reacts with base (collagen)- color: purple
Whats point of microscope?
Study cell
True or false- light microscope is used for histology
False- bright field microscope
What lens are used in bright field lens?
Condenser: Illuminate
Objective: Enlarge
Eyepiece: Magnifies
What type of electron microscopes are there?
- Transmission electron microscope (TEM)
- Scanning electron microscope (SEM)
Which EM has 3D view?
SEM
How to rapidly check biopsies?
- Freeze in liquid nitrogen + use cryosat
- Microtome sections tissue
- Microscope
How can cryosat be used in another way?
- Study of enzymes
- Clear solvent dissolve lipid in fixed tissue
Which are medication application of enzyme histochemistry?
- Perl Prussian blue reaction- check ion
- Pas- checks amylase- glycogemosis & mucopolysaccharidosis
- Lipid- check sphingolipidomic
What are issues of studying tissues?
- 2D view not 3D
- Tissue may distort and cause structural abnormalities called artifacts
- Impossible to show all of tissue
True or false- staining can take up to 2 1/2 days
True depend on size
