Histology Flashcards
What colour do nerve cells stain?
Brown
What colour dye is haematoxylin?
Blue
What colour dye is eosin?
Pink
How is tissue preserved?
First preserved by fixing it in formalin which is an aqueous solution of the gas formaldehyde, this prevents the tissue from rotting.
The samples of tissue to be examined are then embedded in paraffin, a process which involves the extraction of water and a number of other substances from the tissues
How thick are the tissue slices typically?
4 microns
What do you do to examine bone?
Demineralise it, so that you can produce thin sections
Or grind it down to produce a thick slice
What substances within tissues don’t stain?
Glycosaminoglycan extra-cellular jelly
What stain is used to highlight sugars?
Periodic Acid Schiff (PAS)
What colour is the stain of PAS?
Magenta
What stain is used to highlight elastic tissue?
Van Gieson
What colour does Van Gieson stain?
Brown
What stain is used to highlight mucins?
Alcian blue
What colour does Alcian blue stain?
Blue
What size are lymphocytes?
About 10 micrometers in diameter, with very little cytoplasm
What size are motor neurons?
About 100 micrometers wide, with axons up to 1 meter in length
Different shapes of cells …
Spherical/Rounded
Polygonal
Fusiform
Squamous (flattened)
Cuboidal
Columnar
Which cells are generally smaller, dormant/metabolically inactive cells or metabolically active cells and why?
A dormant cell, as they do not need to maintain an elaborate cellular mechanical machinery in order to exist, it only needs a small number of mitochondria, little endoplasmic reticulum.
What do metabolically active cells often contain?
Nucleoli, which are specialisations within the nucleus of the cell and are sites of DNA transcription into RNA
What is the lifespan of the cells that line your intestines?
Several days, probably around 4-5 days
What is the lifespan of red blood cells?
120 days before they are removed
What is the lifespan of cells of your skin and connective tissues?
About a few months
What is the lifespan of cells that make up bones and tendons?
Years
What is the lifespan of skeletal muscle cells?
They have limited regeneration, they last most of your adult life