section 2

Question 1

What is mortality?

Answer 1

The likelihood that a disease will result in death, often expressed as a percentage.

Question 2

What is prevalence?

Answer 2

The total number of cases of a disease in a specific population at a given time.

Question 3

How does prevalence differ from incidence?

Answer 3

Incidence refers to the number of new cases within a specific timeframe, while prevalence includes all existing cases.

Question 4

What is a transcriptional activator?

Answer 4

A protein that binds to DNA to enhance gene expression by promoting RNA polymerase binding.

Question 5

How can the location of a gene affect its expression?

Answer 5

If a gene is moved to a different promoter, its expression may change, leading to altered timing and levels of gene activity.

Question 6

What is epigenetics?

Answer 6

The study of heritable gene expression changes that do not involve alterations in the DNA sequence.

Question 7

What are two major epigenetic mechanisms?

Answer 7

1. DNA methylation: Silences genes by adding methyl groups to DNA. 2. Histone modification: Alters chromatin structure to increase or decrease gene expression.

Question 8

What is alternative splicing?

Answer 8

A process where different combinations of exons are joined together, allowing a single gene to produce multiple proteins.

Question 9

What is polyadenylation?

Answer 9

The addition of a poly(A) tail to the 3’ end of mRNA, increasing its stability and translation efficiency.

Question 10

What are the three stages of translation?

Answer 10

1. Initiation: The ribosome assembles around the start codon. 2. Elongation: Amino acids are added to the growing polypeptide chain. 3. Termination: The ribosome reaches a stop codon, and the polypeptide is released.

Question 11

What is the role of chaperone proteins?

Answer 11

They assist in the proper folding of newly synthesized proteins.

Question 12

How does translation regulation affect protein production?

Answer 12

It controls the efficiency of protein synthesis, impacting cellular function and adaptation to environmental changes.

Question 13

What are the key aetiological factors for lung cancer?

Answer 13

• Smoking.
• Exposure to carcinogens like asbestos.
• Genetic predisposition.

Question 14

What is the pathogenesis of lung cancer?

Answer 14

Chronic exposure to carcinogens leads to genetic mutations that cause uncontrolled cell division and tumour formation.

Question 15

What is the relationship between aetiology, pathogenesis, and disease in hypertension?

Answer 15

• Aetiology: Genetic predisposition, obesity, high salt intake.
• Pathogenesis: Increased arterial resistance, elevated blood pressure.
• Disease: Damage to blood vessels, risk of stroke or heart attack.

Question 16

True or False: Idiopathic diseases have an unknown cause.

Answer 16

True

Question 17

True or False: Pathogenesis refers to the direct cause of disease rather than its mechanism.

Answer 17

False

Question 18

True or False: Congenital diseases are always inherited from parents.

Answer 18

False

Question 19

True or False: Prognosis describes the likely outcome of a disease.

Answer 19

True

Question 20

True or False: Aetiology is the study of disease mechanisms.

Answer 20

False

Question 21

What is diagnosis?

Answer 21

The process of identifying a disease in an individual through clinical history, physical examination, and laboratory investigations.

Question 22

What is the first step in diagnosing a disease?

Answer 22

Documenting the patient’s symptoms.

Question 23

What does a doctor look for during a physical examination?

Answer 23

Clinical signs.

Question 24

What is a diagnostic laboratory test?

Answer 24

A test performed on patient samples to assess biomarkers or detect abnormalities.

Question 25

What are the two types of diagnostic laboratory tests?

Answer 25

- Quantitative measurement (compared to normal reference values). * Subjective assessment (evaluated by a pathologist).

Question 26

What is epidemiology?

Answer 26

The study of disease patterns in populations and how diseases spread over time and place.

Question 27

What are the main aims of epidemiology?

Answer 27

- Identifying disease causes and risk factors. * Planning disease prevention strategies. * Providing adequate healthcare facilities. * Population screening for early disease detection.

Question 28

Give an example of an epidemiological study.

Answer 28

Hepatitis Delta Virus (HDV) studies or age-specific prevalence of coronary heart disease in Australia.

Question 29

What are two main study designs in epidemiology?

Answer 29

Prospective studies (follow subjects over time) and retrospective studies (analyse past exposures).

Question 30

What is relative risk?

Answer 30

A statistical measure used in epidemiology to estimate the likelihood of disease occurrence in an exposed group compared to an unexposed group.

Question 31

What is an autopsy?

Answer 31

A post-mortem examination performed to determine the cause of death and gather medical insights.

Question 32

What are the two main types of autopsies?

Answer 32

Medicolegal autopsies (forensic investigations) and clinical autopsies (for medical research and education).

Question 33

Who performs medicolegal autopsies?

Answer 33

Forensic pathologists.

Question 34

What percentage of diagnostic discrepancies are revealed by autopsies?

Answer 34

Around 30%.

Question 35

What is cell injury?

Answer 35

The response of cells to stress, which can be reversible or irreversible.

Question 36

What are the two main outcomes of cell injury?

Answer 36

- Reversible injury: Cells recover. * Irreversible injury: Leads to cell death.

Question 37

What are the two main types of cell death?

Answer 37

- Necrosis (uncontrolled cell death due to injury). * Apoptosis (programmed cell death).

Question 38

What are the key morphological changes in reversible cell injury?

Answer 38

Swelling of the endoplasmic reticulum and mitochondria, followed by chromatin clumping.

Question 39

What are the main causes of cell injury?

Answer 39

- Hypoxia (oxygen deprivation). * Physical trauma (mechanical injury, extreme temperature). * Chemical agents (cyanide, alcohol, carbon monoxide). * Infectious agents (bacteria, viruses). * Immunologic reactions (allergic responses). * Nutritional imbalances (vitamin deficiencies, malnutrition). * Genetic abnormalities (sickle cell anaemia).

Question 40

What is hypoxia?

Answer 40

Reduced oxygen supply due to conditions such as ischemia or respiratory failure.

Question 41

What is anoxia?

Answer 41

The complete lack of oxygen supply, leading to severe tissue damage.

Question 42

What is ischemia?

Answer 42

The death of cells due to blood supply restriction, leading to a lack of oxygen and nutrients.

Question 43

What determines the cellular response to injury?

Answer 43

The nature, severity, and duration of the injury.

Question 44

What factors influence the consequences of cell injury?

Answer 44

The cell type, functional state, and adaptability.

Question 45

What causes functional and biochemical abnormalities in injured cells?

Answer 45

Damage to essential cellular components like mitochondria, plasma membrane, DNA, and proteins.

Question 46

What are free radicals?

Answer 46

Highly reactive molecules with unpaired electrons that damage cellular components.

Question 47

How are ROS generated?

Answer 47

- Radiation exposure (UV light, X-rays). * Normal metabolic reactions. * Transition metals like iron donating electrons.

Question 48

What are the three main types of ROS-induced cell injury?

Answer 48

- Lipid peroxidation (damaging membrane lipids). * Protein oxidation (disrupting enzyme functions). * DNA damage (mutations and strand breaks).

Question 49

How does ROS cause DNA damage?

Answer 49

The reaction of ROS with thymine in nuclear and mitochondrial DNA, leading to single-strand breaks.

Question 50

How do cells protect themselves from ROS damage?

Answer 50

Antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase neutralise ROS.