Cell Injury and Death Overview

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Questions and Answers

Which of the following correctly describes cellular adaptations?

Adaptations are irreversible changes that lead to cell death.

Adaptations involve alterations that allow the cell to survive under stress. (correct)

Adaptations are permanent structural changes with no functional benefits.

Adaptations only occur in pathological conditions.

Which of the following is NOT a cause of cell injury?

Increased exercise (correct)

Genetic abnormalities

Oxygen deprivation

Chemical agents and drugs

What is the primary effect of ischemia on cells?

It provides excess oxygen to the cells.

It leads to a loss of blood supply and therefore oxygen. (correct)

It reduces cellular waste products immediately.

It enhances cellular metabolic activity.

Which factor can lead to hypoxia?

Decreased hemoglobin levels Signup and view all the answers

Which of the following substances could act as a chemical agent leading to cell injury?

Glucose in hypertonic concentrations Signup and view all the answers

Which of the following describes the role of immunologic reactions in cell injury?

They may contribute to autoimmune diseases causing cell injury. Signup and view all the answers

What is a common result of nutritional imbalances in cellular health?

Protein calorie deficiencies impacting growth. Signup and view all the answers

What is the impact of aging on cellular health?

Cellular senescence and reduced repair abilities. Signup and view all the answers

What appearance does pus typically have due to acute inflammation?

Creamy yellow Signup and view all the answers

What is the characteristic appearance of the necrotic focus in caseous necrosis?

Amorphous granular debris within a distinctive border Signup and view all the answers

In what type of infection is caseous necrosis most commonly encountered?

Tuberculosis infections Signup and view all the answers

What happens to the normal tissue architecture in the event of a renal abscess?

It obliterates the normal architecture Signup and view all the answers

Which type of necrosis results from acute ischemia or severe bacterial infection?

Gangrenous necrosis Signup and view all the answers

What is the gross appearance of tissue in caseous necrosis often described as?

White and cheesy Signup and view all the answers

What happens to the tissue as a result of gangrene that leads to a foul smell?

Digestion of dead tissue by bacteria Signup and view all the answers

Gangrene is a modified form of which type of necrosis?

Coagulative necrosis Signup and view all the answers

What defines hyperplasia?

An increase in the number of cells in an organ or tissue Signup and view all the answers

Under which conditions does hyperplasia typically cease after tissue restoration?

Once the stimulus that caused it is removed Signup and view all the answers

What type of hyperplasia is exemplified by the proliferation of glandular epithelium in the female breast at puberty?

Hormonal Hyperplasia Signup and view all the answers

Which of the following best describes endometrial hyperplasia?

A condition resulting from a balance disturbance between estrogen and progesterone Signup and view all the answers

What distinguishes pathologic hyperplasia from physiologic hyperplasia?

Pathologic hyperplasia can happen without an appropriate stimulus Signup and view all the answers

What initiates compensatory hyperplasia in the liver?

Removal of a portion of the liver Signup and view all the answers

Which factor is primarily responsible for turning off cell proliferation after liver restoration?

Growth inhibitors Signup and view all the answers

How long can hyperplasia persist after the removal of the stimulus?

Only until the tissue reaches normal size Signup and view all the answers

What is the role of the bax gene in apoptosis?

It stimulates apoptosis. Signup and view all the answers

Which physiologic condition does NOT involve evident apoptosis?

Cell depletion in a stable population of neurons. Signup and view all the answers

Which of the following is an apoptosis-inhibiting gene?

bcl Signup and view all the answers

What is a potential effect of excessive accumulation of misfolded proteins in cells?

Endoplasmic Reticulum Stress. Signup and view all the answers

Which situation involves cell death induced by cytotoxic T lymphocytes?

Viral infections like adenovirus and HIV. Signup and view all the answers

Which of the following is considered a pathologic condition with evident apoptosis?

Cell death due to DNA damage. Signup and view all the answers

What trigger can lead to apoptotic cell death due to DNA damage?

Exposure to hypoxia. Signup and view all the answers

What is the primary function of the death-inducing signaling complex in apoptosis?

To activate caspases. Signup and view all the answers

What is the primary difference between dystrophic calcification and metastatic calcification?

Dystrophic calcification occurs in dead or dying tissue, while metastatic calcification occurs in living tissue. Signup and view all the answers

Which condition is not typically associated with dystrophic calcification?

Hyperparathyroidism. Signup and view all the answers

What characterizes metastatic calcification in tissues?

It is associated with abnormalities in calcium metabolism. Signup and view all the answers

Which of the following is a consequence of renal failure related to metastatic calcification?

Retention of phosphate leading to secondary hyperparathyroidism. Signup and view all the answers

Which of the following is a typical example of dystrophic calcification?

Psammoma bodies in carcinomas. Signup and view all the answers

Which condition is likely to cause accelerated bone turnover associated with metastatic calcification?

Paget disease. Signup and view all the answers

What is the role of vitamin D in metastatic calcification?

It is involved in vitamin D-related disorders causing hypercalcemia. Signup and view all the answers

Which of the following is not a cause of metastatic calcification?

Dystrophic calcification in aged tissues. Signup and view all the answers

Study Notes

Overview of Cellular Responses to Stress and Noxious Stimuli

Adaptations in cells are reversible changes to structural and functional states due to physiological or pathological stimuli, enabling survival and continued function.

Causes of Cell Injury

Oxygen deprivation includes hypoxia due to ischemia (loss of blood supply) and anemia (decreased hemoglobin).
Physical agents causing injury include mechanical trauma, temperature extremes (burns/freezing), and radiation or electrical shock.
Chemical agents encompass poisons (e.g., arsenic, cyanide), hypertonic solutions (glucose/salts), environmental pollutants, alcohol, and narcotic drugs.
Infectious agents include viruses, bacteria, fungi, and parasites.
Immunologic reactions involve the immune system causing cell injury, such as in autoimmune diseases and anaphylactic reactions.
Genetic abnormalities can lead to pathologies, evident in conditions like Down syndrome or sickle cell anemia.
Nutritional imbalances include protein-calorie deficiencies, vitamin insufficiencies, and excessive lipids leading to atherosclerosis.
Aging results in cellular senescence, impacting replication and repair capabilities.

Types of Cell Death

Necrosis is uncontrolled cell death due to factors like hypoxia, physical agents, or toxic substances.
- Liquefactive necrosis occurs in the brain, forming cavities due to tissue liquefaction.
- Caseous necrosis characterizes tuberculosis infections, presenting as cheesy, necrotic tissue.
- Gangrenous necrosis involves large-scale tissue death due to ischemia or infection, often leading to putrefaction and foul odors.

Apoptosis

Apoptosis is programmed cell death, crucial for normal development and maintenance of tissue homeostasis.
Genes involved include pro-apoptotic genes (e.g., bax) that stimulate apoptosis and anti-apoptotic genes (e.g., bcl) that inhibit it.

Physiologic and Pathologic Conditions of Apoptosis

Physiologic apoptosis occurs during embryogenesis, hormone-driven tissue involution, and elimination of unnecessary immune cells.
Pathologic apoptosis can be triggered by cytotoxic T lymphocytes, DNA damage, accumulation of misfolded proteins, and viral infections leading to cell loss.

Hypertrophy and Hyperplasia

Hypertrophy is an increase in cell size due to increased functional demand or stimuli.
Hyperplasia involves an increase in cell number, contributing to tissue or organ enlargement.
- Physiologic hyperplasia includes hormonal (e.g., breast tissue during pregnancy) and compensatory types (e.g., liver regeneration post-resection).
- Pathologic hyperplasia denotes excessive proliferation, like endometrial hyperplasia due to estrogen imbalance.

Calcification Types

Dystrophic calcification involves calcium deposits in dead or dying tissue without abnormal calcium metabolism; often seen in necrotic tissues and certain tumors.
Metastatic calcification occurs in living tissues due to hypercalcemia, linked to conditions such as primary or metastatic bone tumors, renal failure, and increased parathyroid hormone secretion.

Key Terms

Psammoma Bodies are dystrophic calcified deposits found in certain malignant tumors, indicating a specific type of calcification associated with cancerous growths.

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Description

This quiz covers the cellular responses to stress and noxious stimuli, focusing on cell injury, cell death, and adaptations. Topics such as necrosis, apoptosis, and pathological calcification are explored to understand how cells respond to damaging conditions. Test your knowledge on these critical aspects of cellular biology.