doc therese Flashcards
swabs collected in avian necropsy
tracheal and cloacal
these should be checked after plucking the feathers
- trauma
- dog bites
- dermatitis
what does opacity in the air sacs indicate
air sacculitis
T/F: if there is fibrinous exudate in the coelom or air sacs, a swab should be placed into bacterial transport media
T
T/F: bursa regresses as birds sexually mature
T
T/F: fresh fecal or distal colon sample can be used to check for enteric parasites like coccidia
T
what do exudates/plaques in the crop and esophagus indicate
Trichomonas/Candida infxn or hypovitaminosis A
what does caseous exudate in the larynx and trachea indicate
ILT
study of microscopic anatomy of cells and tissue
histology
microscopic study of diseased tissue
histopath
processing of tissue in such a manner as to enable microscopy/study of the tissue
histotech
process by w/c constituents of cells are treated in a chemical so that they will withstand subsequent tx w/ various reagents w/ min. distortion or decomposition and keep the tissue in as life like manner as possible
fixation
most common type of fixation
immersion (perfusion, freeze drying)
fixatives that penetrate the cell to cross link proteins
- formaldehyde
- glutaraldehyde
fixatives that dehydrate the cells and cause precipitation of proteins
- methanol
- ethanol
- acetone
fixatives that cause changes in pH and hence denaturation of nucleic acids and salt formation
- acetic acid
- trichloroacetic acid
- zinc acetate
examples of micro-anatomical fixatives
- formal saline
- formal calcium
- buffered neutral formalin
- Zenker’s fluid
- Bouin’s fluid
examples of cytological nuclear fixatives
- Carnoy’s fluid
- Clarke’s fluid
- Fleming’s fluid
examples of cytological cytoplasmic fixatives
- Champy’s fluid
- formal saline
- formal calcium
examples of histochemical fixatives
- buffered neutral formalin
- cold acetone
- acid alcohol
optimum size and thickness of sections
size: 2x2x0.3 cm
thickness: 3-4 cm
it aims to embed the tissue in a solid medium firm enough to support the tissue and give it sufficient rigidity to enable thin sections to be cut and yet soft enough not to damage the knife or tissue
tissue processing
stages of tissue processing
- dehydration - remove fixatives and water from tissue
- clearing - replacing dehydrating fluid w/ a fluid that is totally miscible w/ dehydrating fluid and embedding medium
- impregnation - replacing clearing agent w/ the embedding medium
- embedding
T/F: hydrophilic agent is used in dehydration w/c attracts water from tissue
T
T/F: 75% is the 1st sol’n and used in increasing strengths
F - 70%
examples of hydrophilic agents used in dehydration
- ethanol (best)
- methanol
- methylated spirit
- isopropyl alcohol
main objective of clearing
transparent appearance of tissues
examples of clearing agents
- xylene (best)
- toluene
- chloroform
- citrus fruit oils
- cedar wood oil
it is the standard and preferred medium for embedding
paraffin wax
melting point of paraffin wax
52-56C
plastic point (solidification point)
10C below melting point
it is in pellet form and melts rapidly
paraplast
examples of alternative embedding media
- resin
- agar
- gelatin
- celloidin
precision instrument that cuts sections from the paraffin blocks, thin enough for examination under microscope
microtome