Basics Flashcards
Define tissue
A collection of cells specialised to perform a particular function
What are the 4 types of tissue classification?
epithelial, connective, muscle and nervous
Name the 7 systems of the human body
musclo-skeletal, cardiovascular, respiratory, genitourinary, gastro-intestinal, nervous and reproductive
What is micrometers in metres?
10^(-6) m
What is the diameter of a red blood cell?
7.2 micrometers
Define biopsy
The removal of a small piece of tissue from an organ or part of the body for microscopic examination.
Name the 6 types of biopsy and give an example of where each one would be used
Smear eg. cervix Curettage eg. uterus Needle eg. brain/muscle Direct Incision eg. skin Endoscopic eg. intestine Transvascular eg. heart
What is a microtome?
A machine that cuts specimens embedded in wax into thin slices that we can view under a microscope
Why do biopsies need to be fixed?
To prevent autolysis and kill any bacteria
Name the 2 reagents used for fixing biopsies
Glutaraldehyde
Formaldehyde
What are the 3 steps a fixed biopsy most go through to be embedded in wax?
dehydration (ethanol)
cleaning (xylene)
embedding (56 degrees celsius)
Which stains are most widely used?
Haematoxylin and Eosin
What does haematoxylin stain and what colour?
stains acidic components of the cells purple
eg. nucleolus/chromatin
What does eosin stain and what colour?
Stains basic components of the cells pink
eg. cytoplasmic proteins
What does Periodic-Acid-Schiff stain and what colour?
stains carbohydrates and glycoproteins magenta
eg. mucus and basement membranes
How does contrast microscopy work?
It exploits the interference effects produced when 2 sets of waves combine: used to see detail in living cells
What is different about darkfield microscopy?
The light comes from the side not underneath
What is confocal microscopy?
The imaging of tissues which have been labelled with one or more fluorescent probes. The confocal microscope eliminates the ‘out-of-focus’ flare from the specimens. Illumination is achieved by scanning one or more beams of light across the specimen. This imagining can be used to construct 3D images.
Define histology
The study of the structure of tissues by means of special staining techniques combined with light and electron microscopy.
