MCB Lecture 55 Intro to Pathology Flashcards
What is aetiology?
The cause of the disease
Outline the characteristics of disease
Aetiology Pathogenesis Clinical and pathological manifestations Complications Prognosis Epidemiology
What is Pathogenesis?
The mechanism causing the disease
What are the clinical and pathological manifestations?
These are the structural and functional features of the disease
What are complications?
These are secondary or systemic consequences of the disease
What is prognosis?
This is the expected outcome of the disease
What is epidemiology?
Incidence, prevalence, distribution
Describe the characteristics of disease using the example of cancer
Aetiology: eg. UV radiation
Pathogenesis: radiation causes mutation in the DNA
Clinical and pathological manifestation: tumour
Complications: metastasis
Prognosis: death or remission
Epidemiology: eg. Men 1 in 12, women 1 in 23
What are some of the general causes of cell injury?
Hypoxia Physical trauma Chemical agents Immunologic reactions Infectious agents Aging Genetic defects Nutritional imbalance
Describe how hypoxia can cause disease
Hypoxia damages tissue, because tissues require oxygen to perform all of their function.
What are the causes of hypoxia?
Pneumonia, anaemia, CO poisoning, occlusion
Occlusion -> ischemia -> hypoxia -> tissue damage
What is ischemia?
The reduction of blood flow to an area
What are some chemical agents that cause disease
Poison Alcohol Tobacco Oxygen Glucose, water-salt balance Environmental toxins: lead, mercury
What did Paracelsus say about poisons?
“all substances are poisonous, the right dose separates a poison from a remedy”
What are some infectious agents that cause disease?
Bacteria Viruses Prions Macroparasites Fungi
What is the effect of alcohol on the body?
Alcohol causes changes in liver cells, leading to cirrhosis of the liver
Cirrhosis liver tissue has it’s structure and function interrupted
What is the effect of prions?
Prions are protinaceous infectious particles.
These are mutant form of the proteins
Eg. Creurzfeld Jacob, bovine spongiform encephalitis
The prion causes vacuolation of tissue in the brain
What are some causes of immunological reaction?
Hypersensitivity: allergy Autoimmunity Immune deficiency, acquired or genetic Immune imbalance Graft rejection
Describe what is happening in rheumatoid arthritis
In rheumatoid arthritic, there is an autoreactive immune response concentrated in the joints.
Many immune cells are attracted to the joints
Joints become clogged
Tissue and cartilage is degraded
Describe some ways that genetic defects can cause injury
- single gene mutation, Tay Sachs
- congenital malformation, Trisomy 21
Describe what is happening in Tay sachs disease
There has been a single base pair substitution, leading to a defective ganglioside degredation enzyme
Ganglioside builds up in neurons, damaging the nervous system
Describe some ways that nutritional imbalance can lead to disease
Deficiency
Malnutrition, vitamin (a or b)
Excess
Obesity
Hypertension
Type 2 diabetes
Describe how physical agents can cause disease
- UV radiation
- Pressure
- Heat/ cold
- Electrical
- Mechanical trauma
Describe how aging can lead to disease
Decline in proliferative ability
Effect of exogenous factors
-> cause damage
List some of the causes of injury that we are exposed to every day
Burns Touching something in the freezer Immune responses Scratches, bruises Smoking UV Insect bite
Describe the mechanism of Tay sachs disease
The enzyme that breaks down GM2 gangliosides is dysfunctional.
This ganglioside builds up in the brain, leading to non functional neurons
