histology and microscopy Flashcards
what is histology?
the study of tissue of the body, and how these form organs
what is tissue?
collection of cells with similar function and structure
what is biopsy?
removal of tissue for diagnostic purpose
what is autopsy?
study of organs of a dead body to find out the cause of death
what is the goal of tissue preparation?
to keep the tissue with same structure and composition as found within the body
what are the steps to tissue preparation?
1- fixation
2-embedding
3-sectioning
4- staining
what is the main function of fixation?
preservation of tissue for further examination
what is prevented due to fixation of how?
fixation prevents
1:prevents digestion by inactivating degradative enzyme
2:maintain molecular composition and structure by cross linking proteins
what are the methods of fixation?
1-using fixatives such as
: formalin
:buffered isotonic solution of 37% formaldehyde
2- freezing
what is the function of embedding?
Conversion of fixed tissue to help with sectioning
what are the methods of embedding?
1- dehydration
2- clearing
3- infiltration by embedding substances
describe the methods of embedding
1-Dehydration: using different concentrations of alcohol to remove water
2-Clearing: remaining alcohol is removed
3-Infiltration: placed in melted substances until it becomes infiltered by it
what are the embedding substances used in infiltration?
1-: paraffin
- Using light microscopy
2-: plastic resin
- Using TEM
what is the function of sectioning?
Provide the very thin specimen needed for microscopy
what are the methods of sectioning?
1- Microtome steel
2- Glass blades
