Cell Injury And Cell Death Flashcards
Agents cells can be hurt by
Hypoxia Physical agents Chemical agents Micro organisms Immune mechanisms Dietary insuffiency and deficiencies and dietary excess Genetic abnormalities
Types of hypoxia
Hypoxaemic
Anaemic
Ischaemia
Histiocytic
Types of physical agents that damage cells
Direct trauma
Extremes of temperature
Sudden changes in atmospheric pressure
E.g. of chemical agents that can damage cells
Glucose/ salt in hypertonic solutions High conch of oxygen Poisons Insecticides Herbicides Asbestos Alcohol Illicit drugs Therapeutic drugs
What components of a cell are the principle targets of cell injury?
Cell membranes
Nucleus
Proteins
Mitochondria
What are free radicals?
Reactive oxygen species. They have a single unpaired electron in the outer shell- unstable configuration so react with other molecules to form other free radicals
What do free radicals do?
Attack lipids in cell membranes and cause lipid peroxidation
Damage proteins, carbs and nucleus acids
They are mutagenic
Examples of free radicals
Hydroxyl
Superoxide
Hydrogen peroxide
Enzymes used to break down free radicals
SOD
Catalase
Peroxidases
What do free radical scavengers do?
Neutralise free radicals
Examples of free radical scavengers
Vitamins A, C and E and glutathione
What does transferrin do?
Sequester iron
What does ceruloplasmin do?
Sequester copper
What catalysed the formation of free radicals?
Transition metals
Examples of heat shock proteins
Unfoldases
Stress proteins
Chaperoning