Topic 2 - Examining Cells and Tissues Flashcards
Name the four different types of tissue in the body.
- Connective
- Epithelial
- Muscle
- Nerve
What does connective tissue consist of?
- cells
- extracellular proteins/glycoproteins
- gels
What are the 3 types of muscle tissue?
- cardiac
- smooth
- skeletal
Order these in ascending size: nerve fibres, neurones (nerve cells), nerves.
Neurones < nerve fibres < nerves
Each makes up the next.
What is the only cell visible to the naked eye?
- Oocyte (egg cell)
Define the limit of resolution.
- The smallest distance by which two objects can be seperated and be distinguishable as two separate objects.
How many times better is the resolution in Electron microscopy than light?
1000X
Light = 0.25micrometers
Electron = 0.25nanometers
What is the difference between SEM and TEM?
- For TEM you need to cut a section of the specimen but not for SEM.
What are the functions of these three things in light microscopy: 1.Haematoxylin and Eosin
- Paraffin wax
- Formalin
- Staining for cell components
- Embedding the tissue to slice it
- Preventing putrefaction
Why would we use a BUFFERED formalin solution for fixation in examining tissue?
To make sure the pH is constant and cells wont be damaged.
How do aldehydes stop rotting/putrefaction?
- Forms strong cross links between proteins, holding them in place which doesn’t allow bacteria to break them down.
Haematoxylin and Eosin are used to stain. Which binds to acids and which to bases?
- Haematoxylin = acids
- Eosin = bases
Which staining method is used to identify things with sugars attached?
- The periodic Acid-Schiff stain (binds to sugars)
Briefly explain the concepts of immunohistochemistry and immunoflourescence.
- These techniques utilise specific target antibodies to visualise small structures.
Which useful feature does confocal microscopy have?
- full section scanning, means entire depth of cell/tissue can be examined. It’s 3D.
