510-01 Intro to Histology Flashcards
A __ consists of two or more different types of cells that function together
tissue
What are the 4 primary tissue classes?
- epithelial 2. connective 3. muscular 4. nervous
An ____ is a structure w/ discrete boundaries that is composed of 2 or more tissue types
organ
epidermis is ____ (tissue/organ). Skin is an ____ (tissue/organ).
tissue, organ
____ is the science of preparing tissues for microscopic study
Histotechnology
7 steps of histotechnology for routine, clinical light microscopy: mnemonic?
- Grossing and Fixation 2. Processing 3. embedding 4. sectioning 5. staining 6. coverslipping 7. diagnosis GooFy People Enjoy Saving Sick Cats + Dogs
In gross processing of fresh specimens, why are the specimens cut into small pieces?
to facilitate penetration of fixatives
During gross processing, the specimen can be marked with ink for ____ or to specify a ____
orientation, margin
During gross processing + fixation, specimens are preserved in what fixatives? Why?
- buffered solutions of FORMALDEHYDE or GLUTERALDEHYDE
- to prevent decay
Aldehydes react with ___ in proteins and form stable bridges between adjacent proteins which leaves them unaffected by ____ or other degrading agents
nitrogen, enzymes
2 ways that aldehydes fix proteins:
1) stabilize bonds so that they don’t break down from bacteria
2) stiffens bonds so that tissue gets harder
Processing:
1) During the processing stage of histotechnology, ___ is removed from the tissue and is gradually replaced with ___
2) During processing, alcohol is removed with solvents like ___ or less toxic solvents like ___
3) Solvents are then replaced with mixtures of heated ___ and other ___
1) water, alcohol
2) xylene, limolene
3) paraffin, waxes
During Embedding, processed specimens are oriented in molds filled with ___ ____. After this cools, the embedded specimens are removed from the molds
liquid wax
During sectioning, specimens embedded in paraffin wax blocks are cut on a ___ into thin section, normal ___ microns thick. These sections form a ___ as they are cut from the block.
microtome, 4-5, ribbon
What is the diameter of a red blood cell? Why is that useful?
~8 microns. Most specimens have blood cells, can be used to compare to size of specimen
During sectioning, the ribbon that is formed is then transferred to a __ water bath and floated to remove ___
warm, wrinkles
Why must waxes be removed before staining? How is this done?
Wax must be removed because the stains that are to be used are water-based. Slide is microwaved until proteins stick, then wax is removed with solvents
What is the standard reference stain?
Hematoxylin + Eosin (H&E)