histopathology Flashcards
what is atrophy
reduction in the size
what is hypertrophy
increase in the size of cells
hyperplasia
increase in number of cells
metaplasia
stable change to another cell type
pathological and physiological reason for hypertrophy
caused by myocardial infarction. or pregnancy within the uterus
pathological cause for hyperplasia
prostate nodules forming, wound healing
causes of atrophy
ageing of the thymus or the menopause in the ovaries. coeliacs disease also causes this
causes of metaplasia
puberty with the cervix and the vagina and smoking damaging the epithelial cells.
what are the 3 elements of putrefaction
disfiguration discolouration and dissolution
what are the 11 traits a good fixative has
toxicity, cost, ease of use, doesnt cause any mutations, stops any further decomposition and autolysis of tissue
ACE stands for
Alcohol Clearing Embedding
step one of ihc
wax removal and rehydration
step 2 of ihc
quenching of endogenous enzymes
step 3 of ihc
antigen retrieval via microwave and enzyme
step 4 of ihc
blocking with normal serum
step 5 of ihc
application of primary antibody
step 6 of ihc
secondary antibodies
step 7 of ihc
apply avidin-biotin solution
step 8 of ihc
apply chromagen usually (DAB)
step 9 of ihc
dehydration
what is a polyclonal antibody
antibodies raised in animal cells that are non specific due to reacting with multiple antigens.
what is a monoclonal antibody
produced in hybrid cells and are made to react with a specific antigen with one antibody. higher cost.
early post mortem changes
anaerobic respiration, acidity of blood. coagulation and relaxation. autolysis and skin slippage also occur
late post mortem changes
rigor mortis- rigidity of skeletal muscle
algor mortis- normal cooling as body equilibrates with the environment
livor mortis- gravitational pooling of blood
what is rigor mortis
rigidity of skeletal muscle due to calcification
what is alvor mortis
cooling of the body so its in equilibrium with the external environment
what is livor mortis
this is when there is blood pooling due to gravitational force
stage1 of bone burning
removal of water dye to moisture evaporation
stage 2 of bone burning
decomposition- organic component is lost
stage 3 of bone burning
changes of the inorganic mineral part of bone
stage 4 of bone burning
fusion crystals begin to form due to minerals melting and fusing together
what method is used to process bone
decalcification- acid based/ use of chelating agents
acid based calcification summed up
strong acid- takes 24-48 hours, swells tissue making harder further analysis but is fastest
weak acid- takes longer and can be used alongside formalin in order to counteract damage caused
chelating decalcifying agents summed up
binds to calcium ions. works better with alkaline. slowest process but removes calcium layer by layer talk about edta
reasons why bone is hard to degrade
high pH due to relationship between osseous deterioation and acidity
soil temperature
collagen is resistant to microbrial attack
alcohol step
removes the fixative and water from the tissue and replaces them with dehydrating fluid
clearing
using histoclear to remove alcohol with both the dehydrating fluid and embedding media
embedding step
replaces the clearing agent with embedding media mainly paraffin wax. this leads to block formation
how are damaged proteins removed
tag by 26s proteosome
ubiquitin is transferred by the target protein via an atp dependant enzyme system
