Cellular Adaptation, Cell Injury, Aging, Necrosis, and Apoptosis

These flashcards cover key concepts from the lecture on cellular adaptation, injury, aging, necrosis, and apoptosis.

What is the central idea regarding cellular adaptation in the face of stress?

Cells first try to adapt to stress, but if the stress exceeds capacity, injury and death follow.

What are the two types of injury that can occur when cells face persistent stress?

Reversible injury and irreversible injury.

Define atrophy in terms of cellular adaptation.

Atrophy is the decrease in cell size often due to disuse, denervation, ischemia, malnutrition, or hormonal loss.

What is hypertrophy and how is it caused?

Hypertrophy is an increase in cell size due to increased workload, for example, larger skeletal muscle after exercise.

What characterizes metaplasia?

Metaplasia is the reversible substitution of one mature cell type for another that can better tolerate stress.

What is dysplasia, and why is it significant?

Dysplasia is characterized by abnormal size, shape, and organization of mature cells and often indicates precancerous potential.

What are the most common causes of cell injury?

Hypoxia, toxins, infections, immune reactions, temperature extremes, radiation, and nutritional imbalance.

Explain the process leading to irreversible cell injury.

Irreversible injury occurs when membranes break down and mitochondria fail, often following severe or prolonged stress.

What happens to cells during necrosis?

Necrosis involves uncontrolled, inflammatory cell death characterized by swelling, membrane rupture, and inflammation in surrounding tissues.

How does apoptosis differ from necrosis?

Apoptosis is a controlled, clean process of programmed cell death without inflammation, while necrosis is uncontrolled and causes inflammation.