Cellular Adaptations and Injury

Questions and Answers

What is the primary result of anaerobic glycolysis during oxygen deprivation?

Decrease in ATP production and increase in lactic acid production

What is the effect of reperfusion injury on cellular pH?

Decrease in pH due to acidosis

What is the primary cause of mitochondrial damage during cell injury?

Lack of oxygen

What is the characteristic of necrosis in cell injury?

Enzymatic digestion Signup and view all the answers

What is the effect of detachment of ribosomes on protein synthesis?

Decrease in protein synthesis Signup and view all the answers

What is the primary mechanism of cellular damage during reperfusion injury?

All of the above Signup and view all the answers

What is the characteristic of reversible cell injury?

Cellular swelling due to loss of fluid homeostasis Signup and view all the answers

What is the primary cause of cell injury during ischemia?

Oxygen deprivation Signup and view all the answers

What is the primary cause of swelling in reversibly injured cells?

Failure of the NA+K+ pumps due to ATP depletion Signup and view all the answers

What is the hallmark feature of irreversible cell injury?

Inability to reverse mitochondrial dysfunction Signup and view all the answers

Which of the following is NOT a characteristic of reversible cell injury?

Inability to reverse mitochondrial dysfunction Signup and view all the answers

What is the result of toxic injury disrupting metabolic pathways in organs involved in lipid metabolism?

Fatty change Signup and view all the answers

Which of the following is a characteristic of irreversible cell injury?

Profound disturbance in membrane function Signup and view all the answers

What is the primary consequence of ATP depletion in reversibly injured cells?

Failure of the NA+K+ pumps Signup and view all the answers

What is the result of detachment of ribosomes from the endoplasmic reticulum in reversibly injured cells?

Disruption of protein synthesis Signup and view all the answers

What is the primary difference between reversible and irreversible cell injury?

Ability to reverse mitochondrial dysfunction Signup and view all the answers

What is the primary mechanism of cell injury during ischemia?

Delivery of substrates for glycolysis is compromised Signup and view all the answers

What is the result of severe and prolonged ischemia?

Death by necrosis and apoptosis due to release of cytochrome c from mitochondria Signup and view all the answers

What is the primary cause of reperfusion injury?

Oxidative stress due to release of free radicals from leukocytes and endothelial cells Signup and view all the answers

What is the result of mild ischemia?

Reversible injury due to failure of Na pump and influx of sodium and water Signup and view all the answers

What is the role of blood in reperfusion injury?

Brings calcium that overloads reversibly injured cells Signup and view all the answers

What is the mechanism of chemical injury?

Direct toxicity and conversion to toxic metabolites Signup and view all the answers

What is the consequence of failure of Na pump during ischemia?

Influx of sodium and water Signup and view all the answers

What is the consequence of severe swelling of mitochondria during ischemia?

Death by necrosis and apoptosis due to release of cytochrome c from mitochondria Signup and view all the answers

Study Notes

Cellular Adaptations to Stress

Hypertrophy: increase in cell and organ size
Hyperplasia: increase in cell number
Atrophy: decrease in cell size and number
Metaplasia: reversible change in cells
Dysplasia: abnormal development of cells

Cellular Injury

Causes of cell injury:
- Physical agents (heat, cold, radiation, trauma)
- Oxygen deprivation (hypoxia, ischemia)
- Chemical agents and drugs
- Infectious agents
- Immunologic reactions
- Genetic derangements
- Nutritional imbalances

Reversible vs. Irreversible Injury

Reversible:
- Cellular swelling due to loss of fluid homeostasis
- Hydrophic changes (liquid accumulation)
- Fatty change (lipid vacuoles)
Irreversible:
- Necrosis: enzymatic digestion
- Apoptosis: programmed cell death

Ischemia

Deprivation of oxygen leads to decreased ATP production
Anaerobic glycolysis occurs, producing less ATP and lactic acid
Lactic acid lowers pH, affecting proteins and chromatin
Changes in ion channels and ribosome detachment

Reperfusion Injury

Restoration of blood flow can cause reperfusion injury
High dose of oxygen leads to reactive oxygen species (ROS)
ROS causes cellular damage
Acidosis (low pH) also occurs

Cell Injury Mechanisms

Mitochondrial damage: lack of oxygen, decreased ATP, increased ROS
Physical agents: mechanical trauma, extreme temperatures, radiation, etc.
Chemical agents and drugs
Infectious agents
Immunologic reactions
Genetic abnormalities
Nutritional imbalances

Progression of Cell Injury and Death

Reversible cell injury: functional and structural alterations
Irreversible cell injury: inability to reverse mitochondrial dysfunction and membrane function

Morphology of Cellular Swelling

Swelling of cells and organelles
Blebbing of plasma membrane
Detachment of ribosomes from endoplasmic reticulum
Clumping of nuclear chromatin

Cell Death

Inability to reverse mitochondrial dysfunction
Profound disturbance in membrane function
Ischemic cell injury: oxidative phosphorylation fails, ATP decreases
Ischemia-reperfusion injury: oxidative stress, intracellular calcium overload, inflammation, and activation of complement system

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Identify the different types of cellular adaptations to stress, including hypertrophy, hyperplasia, atrophy, and metaplasia, as well as the causes of cellular injury, such as physical agents, oxygen deprivation, and infectious agents.