Session 1 Flashcards
4 types of tissue?
Connnective tissue, nervous, muscle, epithelia
Define tissue? Define organ?
A collection of cells specialised to perform a particular function.
Aggregations of tissues constitute organs.
Measurement relationship of metre, mili, micro and nanometre and angstrom?
Metre m
Millimetre mm 10-3m
Micrometre μm 10-6m
Nanometre nm 10-9m
Angstrom A 10-10m
Define biopsy?
The removal of a small piece of tissue from an organ or part of the body for microscopic examination.
Types of biopsies:
1) Smear?
2) Curettage?
3) Needle?
4) Direct incision?
5) Endoscope?
6) Transvascular?
1) Collect cells by spontaneous/mechanical exfoliation. Used for cervix and buccal cavity.
2) Remove tissue by scooping/scraping. Used for endometrium.
3) Put needle into tissue to gather cells. Brain, breast and liver.
4) Cut directly into tissue of interest and remove tissue. Used for larynx and skin.
5) Removal of tissue via instruments through an endoscope. Used for lung and intestines.
6) Used for heart and liver.
Why do we fix biopsies?
Name 2 fixatives?
Name a dehydrating agent?
Name 2 clearing agents?
Macromolecules cross-linked, cellular structure preserved, no autolysis or putrefaction.
Formaldehyde and glutaraldehyde.
Ethanol
Xylene/ Toulene
Uses of Haematoxylin and Eosin?
Periodic Acid-Schiff?
HSAB - H stains acid blue e.g nucleolus and chromatin
Eoisin stains bases pink e.g cytoplasm
PAS stains carbs and glycoproteins magenta e.g goblet cells and BM
Define shrinkage artefact?
During the slide preparation process, tissue is dehydrated and then rehydrated leading to abnormalities in the final slide.
What is phase contrast?
Advantage?
Uses interference effects of two combining light waves.
Enhancing the image of unstained cells - still living.
What is dark field?
Advantage?
Used of which disease?
Exclude unscattered beam (light/electron) from the image.
Live an unstained samples
Malaria
What is fluorescence?
Advantage?
Target molecule of interest with fluorescent Ab
Use multiple different fluorescent stains on one specimen
What is confocal?
Advantage?
Tissue labelled with one or more fluorescent probes.
Eliminates “out of focus flare”, 3D from a series of 2D images, imaging of living specimens.
Define epithelia?
Sheets of contiguous cells, of varied embryonic origin that cover the external surface of the body and line internal surfaces.
Examples of ectoderm?
Mesoderm
Endoderm
- Skin
- Epithelia of urogenital tract, blood and lymph vessel lining, pericardial sac, pleura, peritoneum.
- Epithelia of resp and GI tracts and liver.
Define the basement membrane?
the thin, flexible, acellular layer, which lies between epithelial cells and the subtending connective tissue. It consists of lamina reticularis and basal lamina. Acts as a cellular and molecular filter. Relevant in prognosis of malignant melanoma (penetrate BM = worse prognosis). Increase lamina reticularis = thickened BM.
