1.1 Introduction to pathology and disease

Question 1

What is pathology the study of?

Answer 1

1. Aetiology: causal factors, factor that causes disease
2. Pathogenesis: development of disease within the ​body
3. Lesions: structural changes caused by disease
4. Pathophysiology: functional changes
5. Sequelae: consequences of disease

Question 2

Aetiology of disease – causal factors: viruses, bacteria, fungi and parasites

Answer 2

Infection

Question 3

Aetiology of disease – causal factors: trauma, pressure, heat, cold, radiation

Answer 3

Physical

Question 4

Aetiology of disease – causal factors:
- toxic organic and inorganic substances
- toxins produced by infectious organisms

Answer 4

Chemical

Question 5

Aetiology of disease – causal factors: - deficiencies of vitamins and trace elements
- excess vitamins and trace elements

Answer 5

Nutritional

Question 6

Aetiology of disease – causal factors: range of lethal and sublethal defects

Answer 6

Genetic

Question 7

Acute

Answer 7

Of sudden onset and short duration

Question 8

Possible acute disease outcomes?

Answer 8

• a. causes death of the animal, or
• b. resolves due to host defence or clinical therapy, or
• c. becomes chronic disease

Question 9

Chronic

Answer 9

of insidious onset and protracted course

Question 10

Chronic outcome possibilities?

Answer 10

a. progressively destroys tissue compromising its function and endangering life, or

b. its course is halted and the tissue repairs by scarring

Question 11

interplay of factors involved:
Animal

Answer 11

Ex: age, nutrition, immune status

Question 12

interplay of factors involved:
Agent

Answer 12

ex: dose, virulence, single or mixed infection

Question 13

interplay of factors involved:
Environment

Answer 13

Ex: overcrowding, management, temperature extremes

Question 14

What are lesions?

Answer 14

Abnormalities or changes due to disease in living tissues

Question 15

Where are tissues observed?

Answer 15

• Living animals
• tissues surgically removed from the live animal, and
• in animals soon after death (necropsy, post-mortem examination)

Question 16

do lesions occur in dead animals?

Answer 16

No

Question 17

major changes that occur after an animal dies are due mainly to?

Answer 17

autolysis and putrefaction

Question 18

Why is pathology important in veterinary medicine?

Answer 18

Pathology is fundamental to disease diagnosis:
- history
- clinical examination
- clinical pathology
- biopsy or post-mortem examination
- Prognosis and Treatment
- Control and Prevention - the ideal situation

Question 19

Accurate pathology enables?

Answer 19

accurate diagnosis, therapy and control

Question 20

study of blood cells and chemical components

Answer 20

Hematology and biochemistry

Question 21

Cells in smears, aspirates and fluids

Answer 21

Cytology

Question 22

Gross changes in cell body?

Answer 22

Necropsy

Question 23

microscopic examination of tissues selected from the dead body after necropsy, or biopsy/excision of lesions in the living animal

Answer 23

Histopathology

Question 24

microscopic visualisation of enzymatic activity in tissues

Answer 24

Histochemistry

Question 25

detection of specific antibodies or antigens in tissues or fluids (e.g. To show prior exposure to an infectious agent)

Answer 25

Immunological methods

Question 26

fine detail of the surfaces or internal structures of cells, used less often today

Answer 26

Electron microscopy

Question 27

isolation and identification of pathogenic bacteria/viruses/parasites

Answer 27

Bacteriology/Virology/Parasitology

Question 28

analysis of tissues for particular poisons and toxins

Answer 28

Toxicology

Question 29

_______ can also be applied to body fluids.

Answer 29

Biochemistry

Question 30

Urine examination is useful for?

Answer 30

- renal function - urinary infections - renal protein loss - metabolic disease (e.g. diabetes)

Question 31

A common plant poison in the UK is?

Answer 31

ragwort (grazing horses and cattle)