Cell Injury and Cellular Responses

Study Notes

Cell Injury: Definition and Causes

Cell injury refers to the reversible or irreversible damage to cellular structures or functions, leading to cellular dysfunction or death.
Causes of cell injury:
- Hypoxia (oxygen deficiency)
- Infections (bacterial, viral, fungal)
- Toxins (chemical, environmental)
- Physical agents (temperature, radiation, mechanical trauma)
- Nutrient deficiency or excess
- Genetic defects
- Immune-mediated injury

Cellular Responses to Injury

Cellular responses to injury can be:
- Reversible (cellular adaptation, recovery)
- Irreversible (cell death, apoptosis, necrosis)
Cellular responses may involve:
- Inflammation
- Oxidative stress
- Activation of cellular stress responses (e.g., unfolded protein response)
- Alterations in cellular metabolism and signaling pathways

Types of Cell Death

Apoptosis (programmed cell death):
- Regulated process of cellular self-destruction
- Characterized by cellular shrinkage, chromatin condensation, and fragmentation
- Important for development, tissue homeostasis, and immune function
Necrosis:
- Unprogrammed cell death due to injury or disease
- Characterized by cellular swelling, rupture, and inflammation
- Can lead to tissue damage and organ dysfunction

Cellular Changes in Response to Injury

Cellular changes may include:
- Mitochondrial dysfunction
- Endoplasmic reticulum stress
- Lysosomal dysfunction
- Cytoskeletal alterations
- Changes in cellular membrane permeability and transport
These changes can lead to cellular dysfunction, death, or transformation (e.g., cancer)

Consequences of Cell Injury

Consequences of cell injury can be:
- Acute or chronic disease
- Organ dysfunction or failure
- Cancer
- Neurodegenerative disorders
- Inflammation and tissue repair
Understanding cell injury is essential for the development of therapeutic strategies for various diseases.

Description

Understand the concepts of cell injury, its causes, and cellular responses to injury, including types of cell death, cellular changes, and consequences of cell injury. This quiz covers the fundamental principles of cellular pathology and its significance in disease diagnosis and treatment.