Cell Adaption, Injury and Death Flashcards
Etiology
The underlying cause. (Genetic, acquired, or both)
Pathogenesis
Sequence of events that occurs in response to the injurious event. How the disease occurs.
Morphologic Changes
Appearances of tissues or cells that are characteristic in a given disease process. (Diagnostic pathology) Biochemical and molecular changes.
Functional derangement.
Symptoms (What a patient feels) and signs (What a physician sees), clinical course, outcome
Metabolic cause of cell/tissue injury.
Oxygen deprivation. HYPOXIA. Glucose and nutritional imbalance, etc.
Hypoxia
Oxygen deprivation. Neutrophils.
Physical causes of cell/tissue injury.
Cold, heat trauma, etc.
Chemical causes of cell/tissue injury.
Tylenol, alcohol, recreational drugs, pollutants, ingestion of toxic substances.
Immunologic Reactions that cause cell/tissue injury.
Allergies, autoimmune
Genetic causes of cell/tissue injury.
Chromosomal (Down’s), gene-specific (CF), etc.
Infectious causes of cell/tissue injury.
Bacteria, viruses, parasites, fungi, prions.
What is homeostasis?
Cell is in balance with environment and in a steady state, functioning as intended.
What is adaption?
Generally reversible changes in the size, number, phenotype, metabolic activity, or functions of cells in response to changes in their environment.
What does it mean when the damage is irreversible?
Terminal disease.
Hypertrophy
Increase in size in cells, often resulting in increase in size of organ. (Ex. Heart)
Atrophy
Decreased in cell size and number, resulting in reduced size of organ or tissue. (Ex. Brain, muscles)
Hyperplasia
Increase in number of cells. (Ex. Liver regeneration)
Metaplasia
Conversion of one cell type to another. (Ex. Bronchus, esophagus and heart burn)
Dysplasia
Alteration in size, shape and organization of cells within tissue. (Cancer)
What are the vulnerable systems of the cells?
Cell membranes, mitochondria and aerobic respiration, ER and synthesis of proteins and enzymes, DNA integrity and preservation of the genetic apparatus
Why is the cell membrane so easily injured?
Membrane faces the external environment and sustains trauma, extracellular oxidants, proteases, etc.
Requires a constant supply of ATP for normal function (ion pumps)
Lipid molecules in the membrane are easily oxidized and support an oxidative chain reaction called lipid peroxidation.
What are the 6 mechanisms of cell injury?
- Decrease in ATP
- Mitochondrial damage
- Entry of Ca2+
- Increase in ROS
- Membrane damage
- Protein misfolding, DNA damage
What effect does mitochondrial damage have on a cell?
Leakage of pro-appoptotic proteins and a decrease of ATP which leads to multiple downstream effects.
What effect does the entry of Ca2+ have on a cell?
Increase of mitochondrial permeability and activation of multiple cellular enzymes.
What effect does an increase of ROS (Reactive Oxygen Species) have on a cell?
Damage to lipids, proteins and DNA/
How does membrane damage affect the cell?
Plasma membrane: Loss of cellular components.
Lysosomal membrane: Enzymatic digestion of cellular components.