2 How To Examine Cells And Tissues Flashcards
What is the Latin for tissue?
Latin word that means woven
How can vasculitis be indicated in cell slides?
Enlarged RBC
What is limit of resolution, d and NA?
Smallest distance by which two objects can be separated and still be distinguishable as two separate objects
d = limit of resolution
NA = numerical aperture - dimensionless quantity that represents different angles that lens has
What are the types of tissue procurement?
Biopsy or pipelle (sample of tissue)
Curettage (scraping of cells particularly uterus)
Removal of organ
What is used in fixation?
Formalin solution (10% buffered) Formaldehyde Water NaH2PO4 Na2HPO4 Mix May be put in cassette
What are the steps of paraffin wax embedding after fixation?
Dehydrated in different concentrations of alcohols
Immersed in dissolved hot paraffin wax
Tissue orientated in mould, more wax added
Cool to room temp
Eased out of mould
Microtome used to slice into sections
What does H and E stain?
Haemotoxylin and eosin identifies most things in cell
Haemotoxylin stains nuclei acids blue
Eosin stains proteins, cytoplasm and extracellular matrix pink
What happens at the apical of an epithelial cell?
Often secretes sugar on surface to hold water (glycocalyx) to stop dehydration
How do epithelial cells stay together?
Anchoring proteins hold them together
How do epithelial cells communicate with one another?
Between junctions in lateral and basal surfaces
What is present in connective tissue?
Cells
Extracellular proteins/glycoproteins
Gels
What cells are present in connective tissue?
Fibroblasts
Chondrocytes
Osteocytes/osteoblasts/osteoclasts
Stem cells
What is the function of fibroblasts?
Synthesise collagen
What is the function of chondrocytes?
Secrete cartilage and embed in it
What fibres are present in connective tissue?
Collagen
Elastin
Reticular fibres
What is the function of connective tissue?
Binding and support Protection Insulation Storing reserve fuel and cells Transporting substances within the body Separation of tissues
What is the role of tight junctions?
Seals neighbouring cells together to prevent leakage of molecules between them
What is the role of adherens junctions?
Joins actin bundle in one cell to a similar bundle in neighbouring cell
What is the role of desmosomes?
Joins intermediate filaments in one cell to those in a neighbour
What is the role of a gap junction?
Allows the passage of small water-soluble ions and molecules