PATHOLOGY- Intro to pathology

Question 1

What is pathology

Answer 1

The study of disease

Question 2

What is histology

Answer 2

the study of cells and tissue by microscopy

Question 3

What is histopathology

Answer 3

the microscopic examination of tissue in order to study the manifestations of disease

Question 4

What is epidemiology

Answer 4

Population distribution, incidence and prevalence

Question 5

What is pathogenesis

Answer 5

What is the mechanism that causes disease

Question 6

What does primary mean in terms of disease causation

Answer 6

unknown cause

Question 7

What does secondary mean in terms of disease causation

Answer 7

complication or manifestation of an underlying condition

Question 8

what does primary mean in regards to stages of disease

Answer 8

original site of tumour development

Question 9

What does secondary mean in regards to stages of disease

Answer 9

Secondary tumours away from the site of the primary tumour

Question 10

What does the prefix ana- mean

Answer 10

Absence

Question 11

What does the prefix dys- mean

Answer 11

disordered

Question 12

What does the suffix -itis mean

Answer 12

inflammatory process

Question 13

What does the suffix -entasis mean

Answer 13

Dilation

Question 14

What are the 10 steps of tissue testing

Answer 14

1. Extract tissue
2. Fixation
3. Block selection (cut up)
4. Tissue processing
5. Section cutting and mounting
6. Section staining
7. Section scanning
8. Microscopy
9. Diagnosis
10. Prognosis prediction

Question 15

What is tissue fixation

Answer 15

the preservation of tissues through
1. Stopping intrinsic autolytic enzyme action (autolysis)
2. Prevention of bacterial contamination (putrefaction)
3. Increasing mechanical strength to preserve structure / morphology

Question 16

What is the most common tissue fixative used

Answer 16

Formalin (formaldehyde solution)

Question 17

5 features of formalin as a tissue fixative

Answer 17

• Forms protein covalent cross-links
• Good penetration / mechanical strength
• Good tissue morphology preservation
• Poor nucleic acid preservation (DNA/RNA)
• Effective fixation 24-48 hours

Question 18

Name 2 other fixatives

Answer 18

Glutaraldehyde
Ethanol

Question 19

During tissue processing what must you ensure

Answer 19

the tissue must be resistant enough to mechanical trauma in order to slice thinly enough

Question 20

Describe the steps of tissue processing before slicing

Answer 20

• Remove water from tissues by alcohol (dehydration)
• Replace alcohol with xylene (clearing)
• Replace xylene with paraffin wax (wax infiltration)
• Orientate tissue to form a block (embedding / blocking out)

Question 21

What is the most common stain used for section staining

Answer 21

Haemotoxylin and eosin stain (H&E)

Question 22

What does H&E do to the tissue

Answer 22

Haematoxylin stains acidic structures purple (e.g. nuclei)
Eosin stains basic structures pink (e.g. cytoplasm)

Question 23

what can help to provide specific information with tissue testing

Answer 23

using antibodies against a specific target protein

Question 24

What is an issue with using H&E when testing

Answer 24

Isn’t specific