Podcast
Questions and Answers
Which of the following genes are targets for genetic damage, leading to the development of cancer?
Which of the following genes are targets for genetic damage, leading to the development of cancer?
Which of the following is an intrinsic factor that is associated with carcinogenesis?
Which of the following is an intrinsic factor that is associated with carcinogenesis?
Match the carcinogen on the left with a tumour that it is often associated with on the right:
Match the carcinogen on the left with a tumour that it is often associated with on the right:
Ultraviolet radiation = Malignant melanoma Cigarette smoking = Carcinoma of the bronchus Asbestos exposure = Mesothelioma β-naphthylamine = Bladder carcinoma Human papilloma virus = Cervical carcinoma X-irradiation = Leukaemia Aflatoxins = Hepatocarcinoma
The human immunodeficiency virus infects which cells in the body? (Select all correct responses)
The human immunodeficiency virus infects which cells in the body? (Select all correct responses)
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A baby diagnosed with agammaglobulinaemia (Bruton’s disease) will present with what type of infection?
A baby diagnosed with agammaglobulinaemia (Bruton’s disease) will present with what type of infection?
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A viral infection associated with secondary immunodeficiency is:
A viral infection associated with secondary immunodeficiency is:
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Haemorrhage into a joint is termed:
Haemorrhage into a joint is termed:
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The condition where multiple small haemorrhages are seen in the skin and mucous membranes due to a very low circulating platelet number is termed:
The condition where multiple small haemorrhages are seen in the skin and mucous membranes due to a very low circulating platelet number is termed:
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A characteristic of primary shock is low blood pressure mediated by a transient neurovascular reaction.
A characteristic of primary shock is low blood pressure mediated by a transient neurovascular reaction.
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Which type of thrombus would appear to be layered and would only partially block the vascular lumen?
Which type of thrombus would appear to be layered and would only partially block the vascular lumen?
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Which type of thrombus would be found on a heart valve?
Which type of thrombus would be found on a heart valve?
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Match the appropriate condition on the left with its aetiology on the right:
Match the appropriate condition on the left with its aetiology on the right:
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If a patient survives an infarct in the myocardium, the condition is most commonly followed by:
If a patient survives an infarct in the myocardium, the condition is most commonly followed by:
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Match the appropriate term on the left with its definition or association on the right:
Match the appropriate term on the left with its definition or association on the right:
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Individuals with primary hyperaldosteronism may develop secondary hypertension.
Individuals with primary hyperaldosteronism may develop secondary hypertension.
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Which person is likely to have the most severe and advanced atherosclerosis (all patients being of the same age and sex)?
Which person is likely to have the most severe and advanced atherosclerosis (all patients being of the same age and sex)?
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Match the appropriate term with its definition or association:
Match the appropriate term with its definition or association:
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Which person is likely to have the most severe arteriolosclerosis in their renal arterioles?
Which person is likely to have the most severe arteriolosclerosis in their renal arterioles?
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Which of the following conditions is NOT caused by an infection?
Which of the following conditions is NOT caused by an infection?
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Lobar pneumonia is characterized by:
Lobar pneumonia is characterized by:
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All of the following conditions will cause melaena EXCEPT:
All of the following conditions will cause melaena EXCEPT:
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A 52 year old male presents with haematochezia and constipation. Melaena is not evident. What is the most likely diagnosis?
A 52 year old male presents with haematochezia and constipation. Melaena is not evident. What is the most likely diagnosis?
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Ulcerative colitis:
Ulcerative colitis:
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Obstruction in the large bowel is most commonly due to:
Obstruction in the large bowel is most commonly due to:
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Which type of myocardial disorder is diagnosed based on exclusion?
Which type of myocardial disorder is diagnosed based on exclusion?
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Primary amyloidosis may result in amyloid deposited between myocardial fibres.
Primary amyloidosis may result in amyloid deposited between myocardial fibres.
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Match the appropriate condition on the left with its aetiology on the right:
Match the appropriate condition on the left with its aetiology on the right:
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For the following 7 statements, is the answer TRUE or FALSE?
a) Raynaud’s disease leads to the development of Aschoff nodules.
b) Acute bacterial endocarditis may lead to vegetations and septic emboli.
c) An incompetent valve causes blood to flow backwards.
d) Sub-acute bacterial endocarditis usually presents in young IV drug users.
e) Thrombus formation leads to varicose veins.
f) A type III hypersensitivity may lead to arteritis.
g) Polyarteritis nodosa is more common in females.
For the following 7 statements, is the answer TRUE or FALSE? a) Raynaud’s disease leads to the development of Aschoff nodules. b) Acute bacterial endocarditis may lead to vegetations and septic emboli. c) An incompetent valve causes blood to flow backwards. d) Sub-acute bacterial endocarditis usually presents in young IV drug users. e) Thrombus formation leads to varicose veins. f) A type III hypersensitivity may lead to arteritis. g) Polyarteritis nodosa is more common in females.
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Which of the following is likely to result in pulmonary dysfunction?
Which of the following is likely to result in pulmonary dysfunction?
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Which of the following stimuli are likely to cause a cell mediated hypersensitivity in predisposed individuals? (Select all correct responses)
Which of the following stimuli are likely to cause a cell mediated hypersensitivity in predisposed individuals? (Select all correct responses)
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Which patient below is MOST likely to be presenting with COPD?
Which patient below is MOST likely to be presenting with COPD?
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A cell that is important in type I hypersensitivity reactions is the:
A cell that is important in type I hypersensitivity reactions is the:
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Which patient below is LEAST at risk of presenting with asthma?
Which patient below is LEAST at risk of presenting with asthma?
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A patient was given an incompatible blood transfusion. What type of reaction is likely to have occurred?
A patient was given an incompatible blood transfusion. What type of reaction is likely to have occurred?
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An example of type III hypersensitivity is 'serum sickness'.
An example of type III hypersensitivity is 'serum sickness'.
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The accumulation of oedema fluid in the peritoneal cavity is termed:
The accumulation of oedema fluid in the peritoneal cavity is termed:
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Generalized oedema involves increased secretion of:
Generalized oedema involves increased secretion of:
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Which of the following blood losses is an example of an internal haemorrhage?
Which of the following blood losses is an example of an internal haemorrhage?
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In which part of the body may a small volume of haemorrhage be fatal?
In which part of the body may a small volume of haemorrhage be fatal?
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Which of the following terms describes a very small spot of haemorrhage?
Which of the following terms describes a very small spot of haemorrhage?
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What is the main effect of haemorrhage?
What is the main effect of haemorrhage?
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Which of the following is CORRECT regarding congenital heart disease?
Which of the following is CORRECT regarding congenital heart disease?
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Coarctation of the aorta causes cyanosis.
Coarctation of the aorta causes cyanosis.
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Which of the following statements below describes a patent ductus arteriosus?
Which of the following statements below describes a patent ductus arteriosus?
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Which of the following is TRUE regarding pericardial disease?
Which of the following is TRUE regarding pericardial disease?
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Which of the following types of myocardial infarcts is the least common?
Which of the following types of myocardial infarcts is the least common?
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How would you confirm the diagnosis of a suspected myocardial infarct?
How would you confirm the diagnosis of a suspected myocardial infarct?
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A patient is diagnosed with a myocardial infarct. Which of the following is NOT a sequela?
A patient is diagnosed with a myocardial infarct. Which of the following is NOT a sequela?
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Haemorrhage into a joint is termed:
Haemorrhage into a joint is termed:
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The condition where multiple small haemorrhages are seen in the skin and mucous membranes due to a very low circulating platelet number is termed:
The condition where multiple small haemorrhages are seen in the skin and mucous membranes due to a very low circulating platelet number is termed:
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A characteristic of primary shock is low blood pressure mediated by a transient neurovascular reaction:
A characteristic of primary shock is low blood pressure mediated by a transient neurovascular reaction:
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Which type of thrombus would appear to be layered and would only partially block the vascular lumen?
Which type of thrombus would appear to be layered and would only partially block the vascular lumen?
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Which type of thrombus would be found on a heart valve?
Which type of thrombus would be found on a heart valve?
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Match the appropriate condition on the left with its aetiology on the right:
Match the appropriate condition on the left with its aetiology on the right:
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If a patient survives an infarct in the myocardium, the condition is most commonly followed by:
If a patient survives an infarct in the myocardium, the condition is most commonly followed by:
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Match the appropriate term on the left with its definition or association on the right:
Match the appropriate term on the left with its definition or association on the right:
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Individuals with primary hyperaldosteronism may develop secondary hypertension.
Individuals with primary hyperaldosteronism may develop secondary hypertension.
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Which person is likely to have the most severe and advanced atherosclerosis?
Which person is likely to have the most severe and advanced atherosclerosis?
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Match the appropriate term with its definition or association:
Match the appropriate term with its definition or association:
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Which person is likely to have the most severe arteriolosclerosis in their renal arterioles?
Which person is likely to have the most severe arteriolosclerosis in their renal arterioles?
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Which type of myocardial disorder is diagnosed based on exclusion?
Which type of myocardial disorder is diagnosed based on exclusion?
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Primary amyloidosis may result in amyloid deposited between myocardial fibres.
Primary amyloidosis may result in amyloid deposited between myocardial fibres.
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Match the appropriate condition on the left with its aetiology on the right:
Match the appropriate condition on the left with its aetiology on the right:
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Raynaud’s disease leads to the development of Aschoff nodules.
Raynaud’s disease leads to the development of Aschoff nodules.
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Which of the following is likely to result in pulmonary dysfunction?
Which of the following is likely to result in pulmonary dysfunction?
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Which patient below is MOST likely to be presenting with COPD?
Which patient below is MOST likely to be presenting with COPD?
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Which patient below is LEAST at risk of presenting with asthma?
Which patient below is LEAST at risk of presenting with asthma?
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Which of the following stimuli are likely to cause a cell mediated hypersensitivity in predisposed individuals? (Select all correct responses)
Which of the following stimuli are likely to cause a cell mediated hypersensitivity in predisposed individuals? (Select all correct responses)
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A cell that is important in type I hypersensitivity reactions is the:
A cell that is important in type I hypersensitivity reactions is the:
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A patient was given an incompatible blood transfusion. What type of reaction is likely to have occurred?
A patient was given an incompatible blood transfusion. What type of reaction is likely to have occurred?
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An example of type III hypersensitivity is 'serum sickness'.
An example of type III hypersensitivity is 'serum sickness'.
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The accumulation of oedema fluid in the peritoneal cavity is termed:
The accumulation of oedema fluid in the peritoneal cavity is termed:
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Generalized oedema involves increased secretion of:
Generalized oedema involves increased secretion of:
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Which of the following blood losses is an example of an internal haemorrhage?
Which of the following blood losses is an example of an internal haemorrhage?
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In which part of the body may a small volume of haemorrhage be fatal?
In which part of the body may a small volume of haemorrhage be fatal?
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Which of the following terms describes a very small spot of haemorrhage?
Which of the following terms describes a very small spot of haemorrhage?
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What is the main effect of haemorrhage?
What is the main effect of haemorrhage?
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Which of the following genes are targets for genetic damage, leading to the development of cancer?
Which of the following genes are targets for genetic damage, leading to the development of cancer?
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Which of the following is an intrinsic factor associated with carcinogenesis?
Which of the following is an intrinsic factor associated with carcinogenesis?
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Match the carcinogen on the left with a tumour that it is often associated with on the right:
Match the carcinogen on the left with a tumour that it is often associated with on the right:
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The human immunodeficiency virus infects which cells in the body? (Select all correct responses)
The human immunodeficiency virus infects which cells in the body? (Select all correct responses)
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A baby diagnosed with agammaglobulinaemia (Bruton’s disease) will present with what type of infection?
A baby diagnosed with agammaglobulinaemia (Bruton’s disease) will present with what type of infection?
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A viral infection associated with secondary immunodeficiency is:
A viral infection associated with secondary immunodeficiency is:
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Which of the following is CORRECT regarding congenital heart disease?
Which of the following is CORRECT regarding congenital heart disease?
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Coarctation of the aorta causes cyanosis.
Coarctation of the aorta causes cyanosis.
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Which of the following statements below describes a patent ductus arteriosus?
Which of the following statements below describes a patent ductus arteriosus?
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Which of the following is TRUE regarding pericardial disease?
Which of the following is TRUE regarding pericardial disease?
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Which of the following types of myocardial infarcts is the least common?
Which of the following types of myocardial infarcts is the least common?
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How would you confirm the diagnosis of a suspected myocardial infarct?
How would you confirm the diagnosis of a suspected myocardial infarct?
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A patient is diagnosed with a myocardial infarct. Which of the following is NOT a sequela?
A patient is diagnosed with a myocardial infarct. Which of the following is NOT a sequela?
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Which of the following conditions is NOT caused by an infection?
Which of the following conditions is NOT caused by an infection?
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Lobar pneumonia is characterized by:
Lobar pneumonia is characterized by:
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All of the following conditions will cause melaena EXCEPT:
All of the following conditions will cause melaena EXCEPT:
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A 52-year-old male presents with haematochezia and constipation. Melaena is not evident. What is the most likely diagnosis?
A 52-year-old male presents with haematochezia and constipation. Melaena is not evident. What is the most likely diagnosis?
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Ulcerative colitis:
Ulcerative colitis:
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Obstruction in the large bowel is most commonly due to:
Obstruction in the large bowel is most commonly due to:
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Study Notes
Pathology Study Guide Weeks 5-8
Carcinogenesis
- Carcinogenesis: process of initiation and promotion of cancer
- Involves genetic alterations in four classes of normal regulatory genes:
- Growth promoting proto-oncogenes
- Growth-inhibiting tumour suppressor genes
- Genes that regulate apoptosis
- Genes involved in DNA repair
- Genetic alterations lead to abnormal uncontrolled proliferation of cells
- Tumour development involves multifactorial aetiology, including intrinsic and extrinsic factors
Immunopathology
- Immunopathology: abnormality in immune system function leading to pathological state
- Subdivided into:
- Immunodeficiencies
- Hypersensitivities
- Autoimmune disorders
- Immunodeficiencies:
- Primary immunodeficiencies: congenital disease, e.g. agammaglobulinaemia, thymic aplasia
- Secondary immunodeficiencies: acquired, e.g. HIV infection, ageing
- Hypersensitivities:
- Type I: anaphylactic hypersensitivity, e.g. allergic reactions
- Type II: cytotoxic hypersensitivity, e.g. incompatible blood transfusions
- Type III: immune complex mediated hypersensitivity, e.g. vasculitis
- Type IV: cell-mediated hypersensitivity, e.g. contact dermatitis
- Autoimmune disorders:
- Failure of self-recognition, immune system attacks body cells
- Involves autoantigens and autoantibodies
- Examples: Hashimoto's disease, systemic lupus erythematosus (SLE)
Oedema
- Oedema: abnormal accumulation of fluid in intercellular spaces or body cavities
- Subdivided into:
- Localized oedema: confined to a small area of the body
- Generalized oedema: involves the entire body
- Causes of localized oedema:
- Acute inflammation
- Allergic hypersensitivity reaction
- Obstruction to lymphatics
- Impaired venous drainage
- Causes of generalized oedema:
- Right heart failure
- Renal disease
- Cirrhosis of the liver### Oedema
- Oedema is the accumulation of fluid in interstitial tissue or body cavities
- Causes:
- Reduced plasma protein (hypoproteinemia)
- Hormonal mechanisms involving kidneys, adrenal gland, and pituitary gland
- Malnutrition (e.g. kwashiorkor)
- Hyperoestrinism (e.g. ovarian disease)
- Clinically important in two situations:
- Pulmonary oedema (e.g. heart failure or pneumonia)
- Cerebral oedema (e.g. head trauma causing raised intracranial pressure)
Haemorrhage
- Haemorrhage is the escape of blood from the circulation
- Types:
- External (blood shed outside the body)
- Internal (blood lost into interstitial tissues or internal body cavities)
- Effects:
- Hypovolaemia and shock
- Anaemia (if blood loss occurs over a long period)
- Haemorrhagic diatheses are disorders that predispose to haemorrhage
- Congenital (e.g. Haemophilia A)
- Acquired (e.g. clotting factor deficiencies)
Purpura
- Purpura is a form of haemorrhage where blood loss occurs from capillaries throughout the body
- Types:
- Thrombocytopenic (due to decreased circulating platelet numbers)
- Non-thrombocytopenic (due to vascular defects)
- Thrombasthenic (due to abnormal platelet function)
Shock
- Shock is a clinical syndrome characterized by symptoms and signs such as pallor, nausea, hypotension, and confusion
- Types:
- Primary shock (due to injury, pain, or strong emotion)
- Secondary shock (due to disturbance of fluid balance)
- Hypovolaemic shock (due to haemorrhage, plasma loss, or fluid/electrolyte loss)
- Cardiogenic shock (due to cardiac disease)
- Septic shock (due to septicaemia)
Thrombosis and Embolism
- Thrombosis is the formation of a solid or semi-solid mass from blood constituents within the vascular system
- Embolism is the transfer of abnormal material by the bloodstream and its subsequent lodgement in vessels downstream
- Infarction is an area of anoxic necrosis produced by acute interference with tissue blood supply
- Virchow's triad: factors predisposing to thrombosis
- Changes in the vessel wall
- Changes in blood flow
- Changes in blood constituents
Atherosclerosis
- Atherosclerosis is a disease of large arteries involving lipid deposition and calcification
- Characteristic lesions:
- Fatty streaks
- Musculoelastic lesions
- Typical and complicated atheromatous plaques
- Pathogenesis involves hard and soft risk factors, reaction to injury theory of Ross
- Clinical effects:
- Intermittent ischaemic effects
- Thrombosis, embolism, and infarction
- Aneurysms
Hypertension
- Hypertension is a persistent rise in systemic blood pressure above 140/90 mmHg
- Classification:
- Primary (idiopathic) hypertension
- Secondary hypertension (known cause)
- Clinical effects:
- Benign hypertension (long course, renal function preserved)
- Malignant hypertension (rapid deterioration of kidney function, life-threatening)
Infarction
- Infarction is the process of anoxic necrosis due to acute interference of tissue blood supply
- Types:
- Pale infarcts (arterial blood supply obstruction)
- Red infarcts (venous drainage obstruction)
- Mixed infarcts
- Sequelae of infarction:
- Death
- Organization
- Dystrophic calcification
- Sepsis### Arteriosclerosis and Atherosclerosis
- Arteriosclerosis: a disease of small arteries and arterioles, characterized by fibrinoid necrosis and microthrombus formation
- Atherosclerosis: a disease of the aorta and its major branches, characterized by the formation of atheromatous plaques
- Atheromatous plaques develop in four stages:
- Fatty streaks: disputed precursors, consisting of lipid-laden macrophages
- Musculoelastic lesions: definite precursors, consisting of smooth muscle cells, connective tissue fibers, and matrix
- Typical atheromatous plaques: leading to thickening of the intima, causing the lumen to narrow
- Complicated plaques: becoming complicated by ulceration, hemorrhage, dystrophic calcification, thrombosis, and aneurysm formation
- Atheromatous plaques develop in four stages:
Risk Factors for Atherosclerosis
- Hard risk factors: multiplicative, including:
- Hyperlipidaemia (genetics important)
- Hypertension
- Cigarette smoking
- Diabetes mellitus
- Genetics
- Soft risk factors: including:
- Dietary factors
- Obesity
- Lack of exercise
- Stress, lifestyle factors, and personality type
Effects of Atherosclerosis
- Thrombosis, thromboembolism, and infarction
- Manifesting as myocardial and cerebral infarcts
Mönckeberg's Medial Calcification
- A disorder involving medium-sized muscular arteries, characterized by:
- Degeneration and necrosis of the medial smooth muscle
- Dystrophic calcification
- Non-affected intima and patent lumen
Arteriolosclerosis
- A disorder involving arterioles and small arteries, characterized by:
- Fibrinoid necrosis
- Microthrombus formation
- Often associated with systemic hypertension, diabetes mellitus, and aging
Cardiovascular System Disorders
Congenital Disorders
- Left-to-right shunts: leading to pulmonary circulation overload, pulmonary hypertension, and RV hypertrophy
- Pulmonary stenotic lesions: leading to narrowing of the pulmonary artery/valve, causing cyanosis
- Coarctation of the aorta: leading to narrowing/blockage of the aorta, causing headaches and dizziness
- Anomalies of position: including situs inversus and dextrocardia
Pericardial Disorders
- Inflammatory:
- Acute pericarditis: due to bacterial/viral infections, rheumatic fever, uremia, SLE, tumors, MI, trauma
- Chronic pericarditis: due to organized acute pericarditis, tuberculosis, syphilis, SLE, radiation therapy, cardiac surgery
- Non-inflammatory:
- Hydropericardium: leading to cardiac tamponade
- Haemopericardium: leading to cardiac tamponade
- Pneumopericardium: leading to cardiac tamponade
Myocardial Disorders
- Coronary artery insufficiency: due to atherosclerosis and/or thrombosis
- Myocardial infarction (MI): characterized by:
- Subendocardial, septal, subpericardial, and transmural types
- Investigations: troponins, high blood lipids, cardiac enzymes, FBE, chest X-ray, nuclear scans
- Management: defibrillation, fluid replacement, morphine, frusemide, O2 therapy, inotropic agents, acute coronary thrombolysis, analgesics, antiarrhythmics, antithrombotics, rehabilitation
- Sequelae: sudden death, shock/heart failure, fibrosis, pericarditis, aneurysm, thromboembolism, cerebral infarct, arrhythmias
- Amyloidosis: primary and secondary, characterized by:
- Amyloid stained brown by iodine, red by Congo red, see "apple-green" birefringence of Congo red-stained tissue under polarized light
- Cardiomyopathies: diagnosed by exclusion, including:
- Congestive/dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Restrictive cardiomyopathy
- Inflammatory diseases: including:
- Myocarditis: infective and aseptic
- Rheumatic heart disease (RHD): autoimmune, characterized by:
- Aschoff nodules
- Heart valve lesions
- Cor bovinum: characterized by LV hypertrophy due to systemic hypertension
- Cor pulmonale: characterized by RV hypertrophy due to various lung/valve disorders
Endocardial Disorders
- Acute and subacute bacterial endocarditis
- Valvular lesions: stenosis or incompetence, including:
- Congenital
- RHD
- Septic causes
Venous Disorders
- Varicose veins: associated with phlebothrombosis and/or thrombophlebitis
Arterial Disorders
- Raynaud's disease: idiopathic, characterized by vasospasm in young women's hands
- Raynaud's phenomenon: Raynaud's disease symptoms secondary to SLE, RA, Pb poisoning
- Arteritis: seen in Arthus phenomenon or autoimmune states, including:
- Polyarteritis nodosa
Pathology Study Guide Weeks 5-8
Carcinogenesis
- Carcinogenesis: process of initiation and promotion of cancer
- Involves genetic alterations in four classes of normal regulatory genes:
- Growth promoting proto-oncogenes
- Growth-inhibiting tumour suppressor genes
- Genes that regulate apoptosis
- Genes involved in DNA repair
- Genetic alterations lead to abnormal uncontrolled proliferation of cells
- Tumour development involves multifactorial aetiology, including intrinsic and extrinsic factors
Immunopathology
- Immunopathology: abnormality in immune system function leading to pathological state
- Subdivided into:
- Immunodeficiencies
- Hypersensitivities
- Autoimmune disorders
- Immunodeficiencies:
- Primary immunodeficiencies: congenital disease, e.g. agammaglobulinaemia, thymic aplasia
- Secondary immunodeficiencies: acquired, e.g. HIV infection, ageing
- Hypersensitivities:
- Type I: anaphylactic hypersensitivity, e.g. allergic reactions
- Type II: cytotoxic hypersensitivity, e.g. incompatible blood transfusions
- Type III: immune complex mediated hypersensitivity, e.g. vasculitis
- Type IV: cell-mediated hypersensitivity, e.g. contact dermatitis
- Autoimmune disorders:
- Failure of self-recognition, immune system attacks body cells
- Involves autoantigens and autoantibodies
- Examples: Hashimoto's disease, systemic lupus erythematosus (SLE)
Oedema
- Oedema: abnormal accumulation of fluid in intercellular spaces or body cavities
- Subdivided into:
- Localized oedema: confined to a small area of the body
- Generalized oedema: involves the entire body
- Causes of localized oedema:
- Acute inflammation
- Allergic hypersensitivity reaction
- Obstruction to lymphatics
- Impaired venous drainage
- Causes of generalized oedema:
- Right heart failure
- Renal disease
- Cirrhosis of the liver### Oedema
- Oedema is the accumulation of fluid in interstitial tissue or body cavities
- Causes:
- Reduced plasma protein (hypoproteinemia)
- Hormonal mechanisms involving kidneys, adrenal gland, and pituitary gland
- Malnutrition (e.g. kwashiorkor)
- Hyperoestrinism (e.g. ovarian disease)
- Clinically important in two situations:
- Pulmonary oedema (e.g. heart failure or pneumonia)
- Cerebral oedema (e.g. head trauma causing raised intracranial pressure)
Haemorrhage
- Haemorrhage is the escape of blood from the circulation
- Types:
- External (blood shed outside the body)
- Internal (blood lost into interstitial tissues or internal body cavities)
- Effects:
- Hypovolaemia and shock
- Anaemia (if blood loss occurs over a long period)
- Haemorrhagic diatheses are disorders that predispose to haemorrhage
- Congenital (e.g. Haemophilia A)
- Acquired (e.g. clotting factor deficiencies)
Purpura
- Purpura is a form of haemorrhage where blood loss occurs from capillaries throughout the body
- Types:
- Thrombocytopenic (due to decreased circulating platelet numbers)
- Non-thrombocytopenic (due to vascular defects)
- Thrombasthenic (due to abnormal platelet function)
Shock
- Shock is a clinical syndrome characterized by symptoms and signs such as pallor, nausea, hypotension, and confusion
- Types:
- Primary shock (due to injury, pain, or strong emotion)
- Secondary shock (due to disturbance of fluid balance)
- Hypovolaemic shock (due to haemorrhage, plasma loss, or fluid/electrolyte loss)
- Cardiogenic shock (due to cardiac disease)
- Septic shock (due to septicaemia)
Thrombosis and Embolism
- Thrombosis is the formation of a solid or semi-solid mass from blood constituents within the vascular system
- Embolism is the transfer of abnormal material by the bloodstream and its subsequent lodgement in vessels downstream
- Infarction is an area of anoxic necrosis produced by acute interference with tissue blood supply
- Virchow's triad: factors predisposing to thrombosis
- Changes in the vessel wall
- Changes in blood flow
- Changes in blood constituents
Atherosclerosis
- Atherosclerosis is a disease of large arteries involving lipid deposition and calcification
- Characteristic lesions:
- Fatty streaks
- Musculoelastic lesions
- Typical and complicated atheromatous plaques
- Pathogenesis involves hard and soft risk factors, reaction to injury theory of Ross
- Clinical effects:
- Intermittent ischaemic effects
- Thrombosis, embolism, and infarction
- Aneurysms
Hypertension
- Hypertension is a persistent rise in systemic blood pressure above 140/90 mmHg
- Classification:
- Primary (idiopathic) hypertension
- Secondary hypertension (known cause)
- Clinical effects:
- Benign hypertension (long course, renal function preserved)
- Malignant hypertension (rapid deterioration of kidney function, life-threatening)
Infarction
- Infarction is the process of anoxic necrosis due to acute interference of tissue blood supply
- Types:
- Pale infarcts (arterial blood supply obstruction)
- Red infarcts (venous drainage obstruction)
- Mixed infarcts
- Sequelae of infarction:
- Death
- Organization
- Dystrophic calcification
- Sepsis### Arteriosclerosis and Atherosclerosis
- Arteriosclerosis: a disease of small arteries and arterioles, characterized by fibrinoid necrosis and microthrombus formation
- Atherosclerosis: a disease of the aorta and its major branches, characterized by the formation of atheromatous plaques
- Atheromatous plaques develop in four stages:
- Fatty streaks: disputed precursors, consisting of lipid-laden macrophages
- Musculoelastic lesions: definite precursors, consisting of smooth muscle cells, connective tissue fibers, and matrix
- Typical atheromatous plaques: leading to thickening of the intima, causing the lumen to narrow
- Complicated plaques: becoming complicated by ulceration, hemorrhage, dystrophic calcification, thrombosis, and aneurysm formation
- Atheromatous plaques develop in four stages:
Risk Factors for Atherosclerosis
- Hard risk factors: multiplicative, including:
- Hyperlipidaemia (genetics important)
- Hypertension
- Cigarette smoking
- Diabetes mellitus
- Genetics
- Soft risk factors: including:
- Dietary factors
- Obesity
- Lack of exercise
- Stress, lifestyle factors, and personality type
Effects of Atherosclerosis
- Thrombosis, thromboembolism, and infarction
- Manifesting as myocardial and cerebral infarcts
Mönckeberg's Medial Calcification
- A disorder involving medium-sized muscular arteries, characterized by:
- Degeneration and necrosis of the medial smooth muscle
- Dystrophic calcification
- Non-affected intima and patent lumen
Arteriolosclerosis
- A disorder involving arterioles and small arteries, characterized by:
- Fibrinoid necrosis
- Microthrombus formation
- Often associated with systemic hypertension, diabetes mellitus, and aging
Cardiovascular System Disorders
Congenital Disorders
- Left-to-right shunts: leading to pulmonary circulation overload, pulmonary hypertension, and RV hypertrophy
- Pulmonary stenotic lesions: leading to narrowing of the pulmonary artery/valve, causing cyanosis
- Coarctation of the aorta: leading to narrowing/blockage of the aorta, causing headaches and dizziness
- Anomalies of position: including situs inversus and dextrocardia
Pericardial Disorders
- Inflammatory:
- Acute pericarditis: due to bacterial/viral infections, rheumatic fever, uremia, SLE, tumors, MI, trauma
- Chronic pericarditis: due to organized acute pericarditis, tuberculosis, syphilis, SLE, radiation therapy, cardiac surgery
- Non-inflammatory:
- Hydropericardium: leading to cardiac tamponade
- Haemopericardium: leading to cardiac tamponade
- Pneumopericardium: leading to cardiac tamponade
Myocardial Disorders
- Coronary artery insufficiency: due to atherosclerosis and/or thrombosis
- Myocardial infarction (MI): characterized by:
- Subendocardial, septal, subpericardial, and transmural types
- Investigations: troponins, high blood lipids, cardiac enzymes, FBE, chest X-ray, nuclear scans
- Management: defibrillation, fluid replacement, morphine, frusemide, O2 therapy, inotropic agents, acute coronary thrombolysis, analgesics, antiarrhythmics, antithrombotics, rehabilitation
- Sequelae: sudden death, shock/heart failure, fibrosis, pericarditis, aneurysm, thromboembolism, cerebral infarct, arrhythmias
- Amyloidosis: primary and secondary, characterized by:
- Amyloid stained brown by iodine, red by Congo red, see "apple-green" birefringence of Congo red-stained tissue under polarized light
- Cardiomyopathies: diagnosed by exclusion, including:
- Congestive/dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Restrictive cardiomyopathy
- Inflammatory diseases: including:
- Myocarditis: infective and aseptic
- Rheumatic heart disease (RHD): autoimmune, characterized by:
- Aschoff nodules
- Heart valve lesions
- Cor bovinum: characterized by LV hypertrophy due to systemic hypertension
- Cor pulmonale: characterized by RV hypertrophy due to various lung/valve disorders
Endocardial Disorders
- Acute and subacute bacterial endocarditis
- Valvular lesions: stenosis or incompetence, including:
- Congenital
- RHD
- Septic causes
Venous Disorders
- Varicose veins: associated with phlebothrombosis and/or thrombophlebitis
Arterial Disorders
- Raynaud's disease: idiopathic, characterized by vasospasm in young women's hands
- Raynaud's phenomenon: Raynaud's disease symptoms secondary to SLE, RA, Pb poisoning
- Arteritis: seen in Arthus phenomenon or autoimmune states, including:
- Polyarteritis nodosa
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A flexible learning resource to review lectures on pathology delivered in weeks 5, 7, and 8 at your own pace.