Cell Injury and Death Quiz

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Questions and Answers

Which type of hyperplasia involves the enlargement of organs due to hormonal stimulation?

Pathological hyperplasia

Physiological hyperplasia (correct)

Metaplastic hyperplasia

Compensatory hyperplasia

What is the process called where one type of adult tissue is replaced by another type?

Hyperplasia

Dysplasia

Metaplasia (correct)

Atrophy

Atrophy can result from which of the following factors?

Nutritional deficiencies (correct)

Increased workload

Chronic disease (correct)

Hormonal changes (correct)

How do hormones influence cell growth?

By regulating metabolic rates Signup and view all the answers

What effect does aging have on cells?

Decreased response to stress Signup and view all the answers

Which of the following cellular changes is least likely to occur in atrophy?

Increased cell function Signup and view all the answers

In which scenario would metaplasia most commonly occur?

Response to chronic irritation Signup and view all the answers

Which statement regarding hyperplasia is false?

It is always a pathological condition. Signup and view all the answers

Which process involves an increase in the number of cells in a tissue due to a stimulus?

Hyperplasia Signup and view all the answers

What is the main mechanism behind atrophy?

Decreased cell size or number Signup and view all the answers

Which condition describes a change in cell type due to an irritating stimulus?

Metaplasia Signup and view all the answers

What hormonal influence is most commonly associated with stimulating cell growth?

Estrogen Signup and view all the answers

How does aging typically affect cells?

Accumulation of damage and reduced function Signup and view all the answers

Which of the following is a reversible condition resulting from stress on cells?

Hypertrophy Signup and view all the answers

Which factor is least likely to contribute to cell injury associated with aging?

Increased cellular regeneration Signup and view all the answers

What type of immune response can lead to cell damage?

Autoinflammatory response Signup and view all the answers

What is the main mechanism for cell death in highly proliferative tissues?

Apoptosis Signup and view all the answers

Which condition is associated with physiologic apoptosis during developmental processes?

Loss of growth factor signaling Signup and view all the answers

What triggers apoptosis in leukocytes at the end of inflammatory responses?

Loss of survival signals Signup and view all the answers

Which of the following conditions can lead to pathologic apoptosis due to DNA damage?

Activation of proapoptotic BH3-only proteins Signup and view all the answers

How does the decline in hormone levels affect hormone-dependent tissues?

Decreases survival signals Signup and view all the answers

What is the effect of strong recognition of self antigens on lymphocytes?

Induces apoptosis Signup and view all the answers

What type of proteins are activated during infections to induce apoptosis in host cells?

Proapoptotic proteins Signup and view all the answers

Which mechanism is presumed to play a role in the turnover of proliferative tissues like intestinal epithelium?

Loss of growth factor signaling Signup and view all the answers

How is aging primarily reflected in cellular responses?

Reduced response to growth factors Signup and view all the answers

What is an observed characteristic of necrotic cell death compared to apoptosis?

Causes inflammation Signup and view all the answers

What term is used to describe the appearance of lipid vacuoles in the cytoplasm of injured cells?

Fatty change Signup and view all the answers

Which alteration is associated with the plasma membrane during cell injury?

Blebbing Signup and view all the answers

What change occurs in the cytoplasm of injured cells that is characterized by red staining?

Eosinophilia Signup and view all the answers

What is a common feature seen in the mitochondria of injured cells?

Swelling Signup and view all the answers

Which change in the endoplasmic reticulum is associated with cell injury?

Dilation with ribosome detachment Signup and view all the answers

Which of the following describes a change in nuclear appearance during cellular injury?

Clumping of chromatin Signup and view all the answers

What does the presence of myelin figures in the cytoplasm indicate?

Cellular damage Signup and view all the answers

What is the effect of intracytoplasmic vacuoles in nonlethal injury?

Reversible injury Signup and view all the answers

What is the primary function of proteins that leak from necrotic cells into the blood?

They serve as markers of tissue-specific necrosis. Signup and view all the answers

Which protein is specifically associated with cardiac muscle and is used as a marker for necrosis?

Troponin Signup and view all the answers

What occurs during the process of apoptosis?

Cells activate enzymes to degrade their own components. Signup and view all the answers

Which characteristic is associated with apoptotic cells?

Formation of membrane blebs Signup and view all the answers

What does not occur in cells undergoing apoptosis?

Swelling due to cellular stress Signup and view all the answers

What is the primary consequence of plasma membrane damage in cells?

Loss of osmotic balance and inﬂux of fluids Signup and view all the answers

What type of injury can lead to increased degradation of cellular membranes?

Decreased phospholipid biosynthesis Signup and view all the answers

Which of the following is a key factor contributing to lysosomal membrane injury?

Increased intracellular calcium Signup and view all the answers

What is a significant outcome of lysosomal membrane damage?

Release of cellular contents Signup and view all the answers

What role do mutations play in cancer development?

They are central to cancer development. Signup and view all the answers

Which of the following is a major cause of cell injury?

Protein-calorie insufficiency Signup and view all the answers

Which event occurs during increased signaling from IRE1 due to cellular stress?

Activation of protein degradation Signup and view all the answers

How can excessive dietary intake impact health?

It can result in obesity. Signup and view all the answers

What triggers the activation of caspases in cells?

Increased levels of misfolded proteins Signup and view all the answers

How does oxidative stress (ROS) primarily damage cellular membranes?

By oxidative modifications to lipids Signup and view all the answers

What are some physical agents that can damage cells?

Trauma and radiation Signup and view all the answers

What is the basis of all diseases?

Cell injury Signup and view all the answers

What is the role of chaperones during cellular stress?

To facilitate protein folding Signup and view all the answers

What happens during the sequence of events in cell injury?

Cells undergo reversible injury and cell death. Signup and view all the answers

Which of the following conditions leads to irreversible cellular damage?

Excessive lysosomal enzyme leakage Signup and view all the answers

What effect does increased degradation during calcium activation have on cellular membranes?

Promotes membrane damage Signup and view all the answers

What does the deposition of abnormal substances affect?

Various cells and tissues Signup and view all the answers

What are some consequences of cellular adaptations to stress?

Morphological and functional changes Signup and view all the answers

Which is NOT a mechanism that injurious stimuli use to damage cells?

Stimulating cell growth Signup and view all the answers

Which factor significantly contributes to common diseases like type 2 diabetes?

Obesity Signup and view all the answers

What is a key characteristic of necrosis?

Inability to restore mitochondrial function Signup and view all the answers

Which phenomenon is NOT associated with necrosis?

Active regulation by hormonal signals Signup and view all the answers

What typically leads to necrosis in cells?

Severe damage beyond repair Signup and view all the answers

What occurs to the plasma membrane during necrosis?

It experiences loss of function Signup and view all the answers

Which type of injury is necrosis most commonly associated with?

Ischemia and exposure to toxins Signup and view all the answers

What is indicated by irreversible cell injury during necrosis?

Structural integrity of DNA is lost Signup and view all the answers

How is necrosis different from apoptosis?

Necroris is often associated with inflammation Signup and view all the answers

What is a consequence of mitochondrial dysfunction in necrosis?

Decreased oxidative phosphorylation Signup and view all the answers

During necrosis, how do intracellular membranes behave?

They exhibit altered structures Signup and view all the answers

Which of the following accurately describes necrosis?

It is characterized by unregulated cell death Signup and view all the answers

Study Notes

Cell Injury

Cell injury is the root of disease.
Cell injury can be reversible or irreversible.
Irreversible cell injury leads to cell death.

Causes of Cell Injury

Hypoxia and ischemia
Toxins
Infections
Immune reactions
Genetic abnormalities
Nutritional imbalances
Physical agents

Mechanisms of Cell Injury

Biochemical and structural changes occur in most cell types.
Different stimuli cause injury through diverse biochemical mechanisms.

Cell Death

Cell death is a key event in the development of many diseases.
Apoptosis is a programmed cell death mechanism.
Apoptosis eliminates unwanted cells without causing harmful inflammation.

Apoptosis

Causes:
- Loss of growth factors
- Lack of survival signals
- Decrease in hormone levels
- DNA damage
- Accumulation of misfolded proteins
- Viral proteins
- Cytotoxic T lymphocytes (CTLs)
Physiological Functions:
- Embryonic development
- Turnover of proliferative tissues (e.g., intestinal epithelium, lymphocytes)
- Involution of hormone-dependent tissues (e.g., endometrium)
- Removal of leukocytes after immune and inflammatory responses
- Elimination of self-reactive lymphocytes (prevents autoimmune diseases)
Pathological Functions:
- DNA damage
- Accumulation of misfolded proteins
- Viral infections

Cell Injury

Cell injury can be reversible or irreversible, which ultimately leads to cell death
Hydropic change or vacuolar degeneration are terms used to describe nonlethal injury
Fatty change is the appearance of lipid vacuoles in the cytoplasm
Eosinophilia is the staining of cytoplasm red by eosin dye, which is more pronounced in necrosis
Myelin figures are collections of phospholipids derived from damaged cellular membranes

Mechanisms of Cell Injury

Mitochondrial membrane damage disrupts oxidative phosphorylation and ATP generation
Plasma membrane damage causes loss of osmotic balance, leading to influx of fluids and ions
Lysosomal membrane damage releases lysosomal enzymes such as acid hydrolases into the cytoplasm
Increased intracellular calcium leads to activation of phospholipases, which degrade the membrane
Oxidative stress can cause direct damage to cell membranes

Necrosis

Necrosis is the inevitable end result of irreversible cell injury
Characteristics of necrosis:
- inability to restore mitochondrial function
- altered structure loss of function of the plasma membrane and intracellular membranes
- loss of structural integrity of DNA and chromatin

Apoptosis

Apoptosis is a programmed cell death pathway
Apoptosis involves activation of enzymes that degrade nuclear DNA and proteins
Cells break down into fragments, giving the appearance of "falling off" which is the origin of the name

Cellular Adaptations to Stress

Cells adapt to stress through various mechanisms such as:
- Atrophy: reduction in cell size
- Hypertrophy: increase in cell size
- Hyperplasia: increase in cell number
- Metaplasia: replacement of one cell type by another

Depositions of Abnormal Substances

Amyloid: misfolded proteins that can accumulate in tissues
Hemosiderin: iron-containing pigment that can accumulate in tissues
Lipofuscin: pigment that is a sign of cellular aging and oxidative stress

Cell Aging

Cellular aging is a complex process characterized by:
- reduced capacity for cell division
- accumulation of cellular damage
- increased susceptibility to disease
- decreased ability to repair damaged DNA

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Description

Test your understanding of cell injury and death mechanisms. This quiz covers topics such as the causes of cell injury, the processes involved, and the role of apoptosis in health and disease. Explore how these concepts are essential for understanding various diseases.