Lecture 2 Flashcards
What are the four types of tissue?
Epithelial
Connective
Nerve
Muscular
What is the structure of epithelial tissue?
Apical and basal surfaces
Always have a basal layer that sits on top of a connective tissue layer
Communicate through junctions on basal and lateral surfaces
What are the connective tissue layers of the spinal nerve
Endoneurium
Perineurium
Epineurium
Can you give a function of muscles other than movement?
Hormone secretion- heart secrets atrial natriuretic factor which lowers blood pressure
Myostatins which act on the adjacent muscle cell and prevents it from growing
What are the smallest and biggest cells in the body?
Sperm cell and oocyte
What is the limit of resolution
The smallest distance by which two objects can be separated and still be distinguishable as two separate objects
What is the difference in preparation of sample for tem and sem
Use microtome to cut sample in half
What are the three types of electron microscopy?
Freeze fracture
Scanning
Emission
How thin do samples need to be for microscopy?
2 to 20 micrometers
What are the requirements to image tissues by light microscopy?
Preserve with formalin
Fix with paraffin wax
Stain with haematoxylin and eosin
Should you use formalin with buffer or not for your tissue sample?
Should use buffer as it prevents water entering and swelling the tissue
Can you list some methods of tissue procurement?
D and C dilation and curettage Endometrial biopsy Pipelle (also endometrial) Surgical Venepuncture for blood sample Bone marrow aspiration using a jamshidi needle Swab of cheek cells
What would a frozen tissue section be used for?
Surgery as it is quick to prepare and can be used to see if all of a cancer has been removed or not. Can use to check margins to see if clear.
What is immunohistochemistry or immunostaining?
Uses antibodies against a specific antigen with a fluorescent tag attached which can be seen.
What type of microscopy is used in immunohistochemistry or immunostaining?
Confocal microscopy
What is phase contrast microscopy?
Type of light microscopy good for looking at cell cultures. Can see cells going through mitosis etc.
Advantages and disadvantages of cell cultures
Advantages: don’t have to use an animal model, homogeneity of sample and control over physical environment
Disadvantages: can only grow a small amount of tissue at a high cost , hard to maintain, can differentiate into different cells and suffer from aneuploidy, can lose 3D structure, influence of other cells and tissues not maintained
What is dark field microscopy?
Specialised technique where live cells illuminated with light which will not form part of image. Get a black background with bright objects on it.
Why would you use dark field microscopy?
To look at live cells
Why would you use light microscopy
Large field of view
Cheap
Advantages of confocal microscopy
Images very sharp
Entire depth of cell or tissue can be seen
What holds cells together?
Cell to cell adhesion molecules
Extracellular proteins
Internal-external scaffolding
Close proximity (pressure effect)
