Microscopy Flashcards
What are the basic classifications of tissues?
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
What is the basic definition of epithelial tissue?
Epithelial tissue covers body surfaces, line the body cavity and form glands.
Endothelium is the epithelium that lines blood vessels.
What is the basic definition of connective tissue?
Underline epithelia, support and surround other basic tissue types.
Also known as support tissue as they provide metabolic and physical support to other tissue.
What is the basic definition of muscle tissue?
Composed of aggregations of contractile cells responsible for the movement of the body and its parts.
What is the basic definition of nervous tissue?
Gather, transmit and intergrate information from within the body and its external environment.
Process it, provide a memory and action, and control the muscular and glandular activity of the body.
What is TEM?
Transmission electron microscopy
Electrons are fired through the tissue and provide an image of within the cell.
What is SEM?
Electrons are fired over the top of the tissue and scattered and captured by a detector.
External features, 3d appearance.
What are primary lines?
Cells are taken from a patient, more reflective of real life.
But there is only a finite number of cell divisions.
What are cell lines?
Cells are made artifically and can replicate indefinitely.
But mutations can occur so do not behave like real cells.
What is fixing tissue?
Fixing tissue prevents degradation and helps maintain architecture.
Chemical or physical
What is the process of histology?
Fixing
Dissection
Embedding
Sectioning
Staining
Visualisation
What is chemical fixing?
Formalin based
Interacts with amino acids and freezes them in place.
Most commonly used.
What is physical fixing?
Ultra low freezing using liquid nitrogen.
Very quick
Can use osmium tetroxide to fix lipids.
What is embedding?
Embeds the tissue in wax or plastic resin.
This enables cutting very thin sections of tissue, using a microtome.
A cryostat is used for frozen tissues.
Why are tissues stained?
The wax is removed through dehydrydration then stained to make the tissues visible.
Most dyes are acid or basic and bind to different areas of the cell.
