methods for cytological and histological examination. microscopic observations Flashcards
what is the most common procedure used in histologic research?
The preparation of tissue slices or “sections” that can be examined visually with transmitted light. Because most tissues and organs are too thick for light to pass through, thin translucent sections are cut from them and placed on glass slides for microscopic examination of the internal structures.
why is microscopic preparation not preserved?
The ideal microscopic preparation is preserved so that the tissue on the slide has the same structural features it had in the body. However, this is often not feasible because the preparation process can remove cellular lipid, with slight distortions of cell structure.
how are the tissues that are histologically studied prepared?
with a sequence of steps;
* Fixation
* Dehydration
* Clearing
* Infiltration
* Embedding
* Trimming
what is fixation?
Small pieces of tissue are placed in solutions of chemicals that cross-link proteins and inactivate degradative enzymes, which preserve cell and tissue structure.
what are fixatives?
To preserve tissue structure and prevent degradation by enzymes released from the cells or microorganisms, pieces of organs are placed as soon as possible after removal from the body in solutions of stabilizing or cross-linking compounds called fixatives.
