1.1 Introduction to pathology and disease Flashcards
What is pathology the study of?
- Aetiology: causal factors, factor that causes disease
- Pathogenesis: development of disease within the body
- Lesions: structural changes caused by disease
- Pathophysiology: functional changes
- Sequelae: consequences of disease
Aetiology of disease – causal factors: viruses, bacteria, fungi and parasites
Infection
Aetiology of disease – causal factors: trauma, pressure, heat, cold, radiation
Physical
Aetiology of disease – causal factors:
- toxic organic and inorganic substances
- toxins produced by infectious organisms
Chemical
Aetiology of disease – causal factors: - deficiencies of vitamins and trace elements
- excess vitamins and trace elements
Nutritional
Aetiology of disease – causal factors: range of lethal and sublethal defects
Genetic
Acute
Of sudden onset and short duration
Possible acute disease outcomes?
- a. causes death of the animal, or
- b. resolves due to host defence or clinical therapy, or
- c. becomes chronic disease
Chronic
of insidious onset and protracted course
Chronic outcome possibilities?
a. progressively destroys tissue compromising its function and endangering life, or
b. its course is halted and the tissue repairs by scarring
interplay of factors involved:
Animal
Ex: age, nutrition, immune status
interplay of factors involved:
Agent
ex: dose, virulence, single or mixed infection
interplay of factors involved:
Environment
Ex: overcrowding, management, temperature extremes
What are lesions?
Abnormalities or changes due to disease in living tissues
Where are tissues observed?
- Living animals
- tissues surgically removed from the live animal, and
- in animals soon after death (necropsy, post-mortem examination)