Pathology and Causes of Death

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Questions and Answers

What is a key consequence of reactive oxygen species (ROS) on cellular components?

DNA mutations and breaks (correct)

Enhanced enzyme activity

Increased ATP production

Stabilization of fatty acids

Which cellular process is primarily affected by hypoxia that leads to ATP depletion?

Oxidative phosphorylation (correct)

Glycogen synthesis

Fatty acid oxidation

Protein synthesis

How do neutrophils and macrophages use reactive oxygen species effectively?

To kill invading microorganisms (correct)

To generate ATP

To reduce blood flow

To stimulate cell division

Which of the following is NOT a reactive oxygen species mentioned in the content?

Fatty acid Signup and view all the answers

What is the major role of glutathione in relation to free radicals?

It removes free radicals Signup and view all the answers

What condition results from the re-oxygenation of tissues after hypoxia?

Reperfusion injury Signup and view all the answers

What effect does oxidative stress have on the Na+/K+ pump?

It leads to pump destruction Signup and view all the answers

What is a primary effect of lipid membrane damage caused by free radicals?

Disruption of membrane integrity Signup and view all the answers

What is the primary cause of cellular swelling in response to stress or injury?

Water accumulation Signup and view all the answers

Which metabolic process increases as a result of cellular injury, leading to lactic acid production?

Anaerobic glycolysis Signup and view all the answers

What effect does the influx of Ca+ have on cellular activity during injury?

Activation of intracellular enzymes Signup and view all the answers

What is a consequence of ribosome detachment during cellular stress?

Loss of protein synthesis Signup and view all the answers

Which cellular structure is primarily affected by a reduced oxygen supply during injury?

Mitochondria Signup and view all the answers

What is the result of cellular death occurring in large numbers within an organ?

Organ failure Signup and view all the answers

What role do cellular stress responses play during infection or inflammation?

They can potentially cause organismal death. Signup and view all the answers

Which phenomenon is NOT typically associated with necrosis?

Cellular hypertrophy Signup and view all the answers

Which three critical systems are most prominently linked to proximal causes of death?

Brain, heart, and lungs Signup and view all the answers

Which of the following is NOT considered a major distal factor of death?

Trauma Signup and view all the answers

What can lead to cell injury as proposed by Virchow?

Extremes of pH and oxygen tension Signup and view all the answers

Which type of inflammation may lead to additional cell injury despite successfully fighting infections?

Chronic inflammation Signup and view all the answers

How can diabetes lead to death according to the information provided?

By leading to disturbances in glucose homeostasis affecting critical systems Signup and view all the answers

What role does the immune system play in the context of disease and death?

It contributes to both disease processes and responses to infections Signup and view all the answers

Which of the following best summarizes the relationship between cell injury and disease?

Cell injury can result from both external and internal factors Signup and view all the answers

What process is primarily responsible for digestion of cellular proteins during apoptosis?

Proteasome system Signup and view all the answers

Which of the following correctly describes reversible cell injury?

Cell swelling or fatty deposits Signup and view all the answers

Which component of cell adaptation primarily associates with the heat shock response?

HSF-1 trimer Signup and view all the answers

What is a significant trigger for the dissociation of heat shock factors from cytosolic complexes?

Stress conditions Signup and view all the answers

What happens when cells are unable to adapt to stress?

They will suffer cell damage. Signup and view all the answers

How does Na+/K+-ATPase activity affect cell swelling?

Its shutdown leads to sodium influx. Signup and view all the answers

What does the activation of heat shock proteins by heat shock factors involve?

Transcriptional activation Signup and view all the answers

Which of the following statements about autophagy is true?

Organelles are encapsulated by membranes and digested. Signup and view all the answers

What factor does NOT influence a cell's decision-making process in response to stress?

Environmental temperature Signup and view all the answers

Which of the following describes the process of cell atrophy?

Reduction of cell volume Signup and view all the answers

How do cells respond to stress when the stimulus is removed?

They adapt and return to normal Signup and view all the answers

What occurs when inflammation persists in an unhealthy host?

Organ failure and death Signup and view all the answers

What is a potential benefit of short-term inflammation in a healthy host?

Beneficial immune response Signup and view all the answers

What defines the cellular response to injury in a semi-autonomous manner?

Individual decision-making of each cell Signup and view all the answers

Which term describes the increase in cell number due to stress adaptation?

Hyperplasia Signup and view all the answers

Study Notes

Pathology

Study of disease and injury
Occurs when there is damage to cells
Focuses on:
- Aetiology: Causes of disease
- Pathogenesis: How diseases develop
- Effects on diseased cells and tissues

Causes of Death

Proximal causes: Systems failure in:
- Brain
- Heart
- Lungs
Distal factors: Original problems causing system failures:
- Infection
- Cancer
- Injury

World Health Organisation (WHO) Top 10 Causes of Death

Ischaemic heart disease and stroke dominate the list, common in aging populations
Major proximal causes:
- Brain failures (#2, #7)
- Heart failure (#1)
- Lung failures (#3, #4, #6)
Major distal factors:
- Inflammatory diseases: (#1, #2, #3, #7, #9)
- Infectious diseases: (#4, #5, #8)
- Cancers: (#6)

Cell Injury

Proposed by Virchow as the basis of disease
Caused by:
- Extremes of oxygen tension or pH
- Lack of ATP
- Exposure to toxins, drugs, and chemicals (xenobiotics)
- Cold and heat
- Prolonged deprivation of vital nutrients
- Trauma
- Aging
- Infection by bacteria, fungi, parasites, and viruses

Reactive Oxygen Species (ROS)

Created by:
- Ionizing radiation
- Reperfusion injury
- Xenobiotics
Normal byproducts of reactions catalyzed by oxidase enzymes
Short half-lives but highly reactive
Damage to DNA, proteins, and lipids, creating more free radicals
Used by neutrophils and macrophages to kill microorganisms, but can damage host cells
Reperfusion injury:
- Occurs when tissue is reoxygenated after hypoxia
- Damages endothelium of small blood vessels
- Contributes to inflammation and thrombosis

Impaired Energy Homeostasis (Cellular Starvation/Suffocation)

ATP generated by:
- Oxidative phosphorylation: In the presence of oxygen
- Glycolytic pathway: In the absence of oxygen
Consequences of reduced oxygen supply:
- ATP depletion:
  - Reduced activity of Na+/K+ pump (sodium accumulates, K+ lost)
  - Water accumulation, ER dilation, cell swelling
  - Increased glycolysis, production of lactic acid, decreased pH, reduced enzyme activity
- Influx of Ca+: Increased activity of proteases, phospholipases, endonucleases, and ATPases
- Ribosome detachment: Loss of protein synthesis

Cell Responses to Stress and Injury

Cells can adapt to stress and injury
When adaptation limits are reached, cells die
Cell death can occur before stress levels reach those limits
Large-scale cell death in an organ leads to organ failure and death
Immune responses to infection/inflammation can cause organismal death
Cells make individual decisions based on:
- Type of injury
- Duration
- Severity
- Cell type
- Capacity to adapt
- Genetic makeup

Cellular Response to Stress

Adaptation: Reversible change to cope with stress
- Hypertrophy: Increase in cell size
- Hyperplasia: Increase in cell number
- Atrophy: Reduction in cell complexity
Cell damage: May be reversible or irreversible
- Reversible: Cell swelling or fatty deposits
Irreversible injury:
- Apoptosis: Programmed cell death
- Necrosis: Accidental cell death

Cell Adaptation (Protective Responses to Stress)

Heat shock response: Fundamental reaction to injury
- Heat shock factors (HSFs): Cytosolic proteins that bind heat shock proteins (HSPs)
- Dissociation of HSFs by stress: Activate transcription of HSP genes
- HSPs: Chaperone proteins that protect cells from damage, promote protein folding, and prevent protein aggregation
- Preconditioning: Exposure to mild stress can induce HSF and HSP production, leading to increased resistance to subsequent stress

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Description

Explore the fundamental concepts of pathology, focusing on cell injury and the causes of death as identified by the World Health Organization. This quiz covers key topics such as aetiology, pathogenesis, and the major proximal and distal factors contributing to disease. Test your understanding of the intricate relationship between cellular damage and health outcomes.