lecture 1 Flashcards
what is the meaning of a tissue
a collection of cells specialised to perform a particular function
what is an organ
A collection of tissues
name 4 types of tissue
epithilial, connective, nervous, muscle
what is histology
the study of structures of tissues using different stains, light and electron microscopy. gold standard of diagnosis, final proof, spread of disease
relationship between M, mM, uM, nM
0, 10-3, 10-6, 10-9
what is a biopsy
removal of a small piece of tissue from an organ/ part of the body for microscopic exam
what is curettage
use a sharp edged spoon to obtain endometrial lininf of uterus
what is needle biopsy
heart, liver, breast, kidney
what is transvascular
use x ray to follow a prove, then biopsy heart/liver epithilia with pincer
what is endoscopic
blow air into the tissue to expand it, lung intestine, bladder
why does tissue need to be fixed
fresh biopsy is wet and bloody, lysosomal enzymes break down structure
what can you fix tissue with
glutaraldehyde and formaldehyde
describe a fixed biopsy
macromolecules are cross linked, cellular structure is preserved, no autolysis or putrefaction
tissue processing causes shrinkage artefacts, how?
dehydration and rehydration in the fixing process causes it
name 2 different stains used on tissues
Haemotoxylin & Eosin, Periodic Acid,Schiff
what does haemotoxylin stain
it stains acidic parts of cell purple e.g. rna and chromatin
what does eosin stain
stains basic parts of cell pink, e.g. cytoplasmic proteins. extracellular proteins are pink
what does periodic acid schiff stain
stains carbs and glycoproteins magenta. Pink components and purple background
what stains tissue blue
Azurea
advantages of phase contrast
uses interference effects of 2 combining light waves to enhance image of unstained cells
advantages of dark field
unscattered beam from image, increases contrast
fluorescence microscopy
targets a molecule of interest with a fluorescent Ab, can use many fluorescent stains on one specimen
confocal microscopy
tissue is labelled with 1 or more fluorescent probes which eliminates out of focus flare, 3D image form 2D image
