Xiao

Question 1

What are the first three steps in tissue processing?

Answer 1

Fixation
Decalcification
Dehydration

Question 2

Which part of the tissue processing is optional and what does it do to the tissue?

Answer 2

Decalcification
- removes calcium or lime salts from the tissues

Question 3

What are the advantages and disadvantages of fresh tissue examination?

Answer 3

Advantages:
Protoplasmic activities such as mitosis, motion, phagocytosis, and pinocytosis can be seen.

Disadvantages:
Not permanent. Changes after death are commonly seen.

Question 4

What are the signs of death during somatic death?

Answer 4

CNS failure
Respiratory failure
Cardiovascular failure

Question 5

Fixation is also known as ______.

Answer 5

Preservation

Question 6

What is the primary goal of fixation?

Answer 6

To preserve the morphologic and chemical integrity of the specimen

Question 7

Give an example of an Additive solution for fixation.

Answer 7

Formaldehyde
Osmium tetroxide
Mercuric chloride

Question 8

Give at least 5 characteristics of a good fixative

Answer 8

1. Cheap
2. Stable
3. Safe to handle
4. Kill the cells quickly
5. Produce minimum shrinkage
6. Harden the tissues properly
7. Inhibits bacterial decomposition and autolysis
8. Permit rapid and even tissue penetration
9. The optimum osmolality for a specific tissue and fixative type
10. Make cellular components insoluble
11. Permit subsequent application of many staining procedures

Question 9

Give at least 5 simple fixatives

Answer 9

1. Aldehydes (Formaldehyde, Glutaraldehyde)
2. Metallic Fixatives (Mercuric chloride, Chromic acid, Lead)
3. Picric acid
4. Acetic acid
5. Acetone
6. Alcohol
7. Osmium tetroxide
8. Heat