L2 Stress and Injury

Question 1

What are the characteristics of disease?

Answer 1

APPCCPE
Aetiology (etiology): cause of the disease
Pathogenesis: mechanism of causing disease eg. HIV
Pathology: Molecular and morphologic changes to cells or tissues, appearance of the disease
Clinical manifestations: signs & symptoms
Complications: 2ndary, systemic or remote consequences of disease
Prognosis: anticipated course of disease
Epidemiology: incidence, prevalence & distribution

Question 2

Pathogenesis

Answer 2

mechanism of causing disease

eg genetic alternation (smoking)

Question 3

Aetiology (etiology)

Answer 3

cause of the disease

eg smoking

Question 4

Pathology

Answer 4

Molecular and morphologic changes to cells or tissues, appearance of the disease
eg. lung tumor (smoking)

Question 5

Clinical manifestations

Answer 5

signs & symptoms 
eg breathlessness (smoking)

Question 6

Complications

Answer 6

2ndary, systemic or remote consequences of disease
eg metastasis (smoking)

Question 7

Prognosis

Answer 7

anticipated course of disease

eg death/remission (smoking)

Question 8

Epidemiology

Answer 8

incidence, prevalence & distribution 
eg risk (smoking)

Question 9

What are the types of adaptation?

Answer 9

Physiological adaptation-cellular response to normal stimulation
• Hormones eg puberty, growth of tissue
• Endogenous chemicals

Pathological adaptation: response to stress to avoid injury

Question 10

Physiological adaptation

Answer 10

cellular response to normal stimulation
• Hormones eg puberty, growth of tissue
• Endogenous chemicals

Question 11

Pathological adaptation

Answer 11

response to stress to avoid injury

Question 12

Hypertrophy

Answer 12

− Increased demand
− Increased work load (physiological and pathological stimuli) 

− Increased size of cells resulting in increased size of organ 

No new cells, just larger cells 

Non-dividing cells increase in size (myocytes of heart, skeletal 

•Body builder -> increased work load -> bigger muscle cells -> rippled physique


Pathological adaptation: stop going to the gym, lose 6 pack, no injury induced

•Hypertension-> increased work load -> enlarged heart -> improved performance -> degeneration

Question 13

Hyperplasia

Answer 13

− Increase in number of cells in and organ or tissue
− Only in cell populations capable of dividing

− Physiological and pathological response
− Stimulated by growth factors

Question 14

Atrophy

Answer 14

− Reduced size of organ resulting from decrease in cell size and number. 

− Eat own organelles, may stop synthesis of proteins, apoptosis
− Physiological atrophy is common during normal development (embryonic structures webbing between fingers, uterus following pregnancy) 

− Pathologic atrophy depends of the underlying cause. 


Question 15

Consequences of Atrophy

Answer 15

• Decreased work load, eg broken leg in cast, loss of skeletal muscle
Immobilization 

• Loss of innervation 

• Loss of blood supply, reduced nutrients 

• Inadequate nutrition 

• Loss of endocrine stimulation 


Question 16

Metaplasia

Answer 16

− Change in the type of cells to protect from injury
− Replacement of one differentiated cell type with another
− Cells sensitive to stress replaced by a cell type better able to withstand stress
− Stem cell reprogramming

Question 17

Causes of cell injury

Hypoxia-what is it caused by?

Answer 17

Hypoxia

− Oxygen deficiency

− Interferes with aerobic oxidative respiration

Caused by
− Pneumonia=inadequate oxygenation

− Blood loss anemia, less RBC
to carry oxygen
− Carbon monoxide poisoning, Hb binds more tightly to CO than

Question 18

8 causes of cell injury

Answer 18

Hypoxia 
Chemical agents 
Infectious agents 
Immunologic reactions 
Genetic defects
Nutritional imbalance 
Physical agents 
(+ ageing)