11-10-21 - Classification of Disease Flashcards
1
Q
What is disease?
A
• Disease is a disorder of function in a human that produces specific symptoms and/or affects a specific location and is not simply the result of direct injury.
2
Q
How do we classify conditions?
What are examples of this?
A
- Functional – this could be a sore head – this is not enough detail, and could be for any number of reasons.
- Biological – haemorrhage, tumour, trauma – this gives more detail than functional classification
- Socioeconomic and health – Related to something that has happened due to socioeconomic patterns of behaviour – a hangover
- Functional again – vascular anomaly, migraine
- Systems or precision medicine – any or all of the above
3
Q
What is aetiology?
What is pathogenesis?
What is sequalae?
What does morphological mean?
A
- Aetiology is the cause, set of causes, or manner of causation of a disease or condition (cause)
- Pathogenesis – the manner of development of a disease.
- Morphological – relating to the form or structure of things.
- Sequelae – a condition which is the cause of a previous disease or injury
4
Q
What are the 6 characteristics of disease?
A
- Aetiology
- Pathogenesis
- Manifestations (clinical, morphological, functional)
- Complications
- Outcome
- Epidemiology – particular outcome for certain people?
5
Q
What are the 5 factors of identification of cause
A
- Probability of disease – someone who smokes a lot has a higher probability of lung cancer, yet 4% of those with lung cancer don’t smoke
- Host predisposition – prostate cancer more likely in African Americans as they have a genetic predisposition for it.
- Cause
- Causal associations – chain of events (this causes this causes this)
- Kochs postulates
6
Q
What are Koch’s postulates used for?
What are Koch’s postulates?
A
- Kochs postulates are used when evidence is required to stablish an etiologic (aetiology) relationship between microorganisms and disease
- Koch’s postulates:
- Microorganisms must be observed in every case of the disease
- It must be isolated and grown in pure culture
- The pure culture, when inoculated in animals, must reproduce this disease
- Microorganism must be recovered from the diseased animal
7
Q
What 4 different categories can cause be a part of?
What is an example?
A
- Genetic
- Environmental – infection, chemicals, radiation, medical trauma
- Combination (multifactorial)
- Unknown – primary, essential, idiopathic, spontaneous, cryptogenic (all unknown)
- E.g diabetes – there is a strong genetic predisposition for diabetes, but obesity puts the person at increased risk.
8
Q
What is pathogenesis?
What are examples of pathogenesis?
How are aetiology and pathogenesis linked?
A
- The manner of development of disease
- Examples – inflammation, degeneration, carcinogenesis, immune reactions (allergy)
- The same aetiology may lead to different pathological endpoints e.g haemophilus influenza can cause sniffles, meningitis, pneumonia
- The same end point may reflect different aetiology e.g cirrhosis of the liver can be caused by alcoholism or obesity
9
Q
What are the 6 structural manifestations of disease?
What is an example of this?
A
- Space-occupying lesion
- Deposition of abnormal material
- Abnormally sited tissue
- Loss of healthy tissue
- Obstruction of a tube
- Rupture of hollow viscus
- E.g tumour growing in the head – manifestations related to the fact there is a tumour growing inside limited amount of space
10
Q
What are the 4 functional manifestations of disease?
What is an example of this?
A
- Excessive secretion of cell product
- Insufficient secretion of cell product
- Impaired nerve conduction
- Impaired muscle contraction?
- E.g tumour may produce a hormone – patient prevents with effects of producing too much anti-diuretic hormone
11
Q
Nomenclature of disease
A
- Primary vs secondary – myocardial ischaemia secondary to diabetes, need to deal with both
- Acute vs chronic – acute is a sudden onset, chronic is developing slowly over time
- Benign vs malignant – benign tumours stay in their primary location without invading other sites in the body. Malignant tumours may infiltrate and spread somewhere else
- Eponymous name – diseases named after a person e.g Parkinson’s or Alzheimer’s
- Syndrome vs disease – a syndrome is a collection of things that could be regarded as disease on their own, hence the name syn-drome
- Disorders of growth – anything from too few to too many cells and gong out of control
- Inflammation and repair – acute? Chronic? Fibrous repair? Scarring? Regeneration
- Degeneration – decline/deterioration
- Thrombosis, blood coagulability – thrombosis is blood clots forming in the blood vessels
12
Q
Why do we classify disease?
What is prognosis, treatment, prediction and epidemiology?
A
- We classify disease in order to understand, communicate, and pass on accurate information e.g patient to clinician, clinician to clinician, clinician to laboratory
- Prognosis – what is going to happen to the patient
- Treatment – what we can treat the patient with
- Prediction – if we give the treatment, will it work?
13
Q
What is the TNM staging system used for?
A
- The TNM staging system is used to describe the extent and severity of someone’s cancer
- T – extent of tumours
- N – whether cancer cells have spread to local lymph nodes
- M – Whether cancer cells have spread to other parts of the body (has metastasis occurred)
14
Q
What is epidemiology?
What 4 areas does it assess?
What 5 things is it affected by?
A
- Epidemiology is the study and analysis of distribution, patterns, and determinants of health and disease conditions in defined populations
- Incidence - number of cases happening per period of time
• Prevalence – Number of people in a population who have a particular disease at a specified appoint in time
• Remission – a decrease in severity or disappearance of disease
• Mortality - death rate - Epidemiology is affected by:
- Age
- Time
- Geography
- Socioeconomic factors e.g income, education, employment
- Occupational factors – health outcome among workers e.g noise, chemicals, heat, radiation in their environment
15
Q
Why might mortality from ischaemic heart disease by different in developed countries?
A
- Some countries are generally healthier than others
- There may be a difference in how deaths are reported in each country, which is why it is important that everything is standardized.
