[P] Week 1: Cell Injury, Cell Death, and Adaptations - Part 2 Flashcards
THE FOUR ASPECTS OF DISEASE
- Cause of disease
- Has two factors, genetic and acquired
Etiology
THE FOUR ASPECTS OF DISEASE
- Sequence of events in the response of cells or tissues to the etiologic agent
- Initial stimulus to the ultimate manifestation of the disease
PATHOGENESIS
THE FOUR ASPECTS OF DISEASE
Structural alterations in cells or tissues characteristic of a disease or diagnostic of an etiologic process
Molecular and Morphologic Changes
THE FOUR ASPECTS OF DISEASE
- its components contains: genetic, biochemical, and structural changes in cells and tissues
- Lead to the clinical manifestations (symptoms and signs) of disease
- Progress (clinical course and outcome)
Functional Deragnements and Clinical manifestation
Match
Injurious Stimulus:
1. Altered Physiological Stimuli & Some Non-Lethal Injurious Stimuli
2. Increased Demand and Increased Stimulation
3. Decreased Nutrients and Decreased Stimulation
4. Chronic Irritation (Physical or Chemical)
Cellular Response
A. Cellular Adaptations
B. Metaplasia
C. Atrophy
D. Hyperplasia, Hypertrophy
- A
- D
- C
- B
Match
Injurious Stimulus:
1. Reduced Oxygen Supply, Chemical Injury, Microbial Infection
2. Acute and Transient
3. Progressive and Severe (including DNA Damage
4. Metabolic Alterations (Genetic or Acquired) and Chronic Injury
5. Cumulative Sublethal Injury Over Long Life Span
A. Intracellular Accumulations; Calcification
B. Cell Injury
C. Cellular Aging
D. Irreversible Injury, Cell Death (Necrosis or Apoptosis)
E. Acute Reversible Injury, Cellular Swelling, or Fatty Change
- B
- E
- D
- A
- C
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ADAPTATIONS OF CELLULAR GROWTH & DIFFERENTIATION
Reversible changes in response to changes in environment:
- Size
- Number
- Phenotype
- Metabolic Activity
- Functions of Cells
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
what are the cellular responses to stress and noxious stimuli?
Hypertrophy, Hyperplasia, Atrophy, and Metaplasia
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
- Increase in size of cells, increase in organ size
- NO new cells, just larger cells
- Affects cells incapable of proliferation
- Synthesis of more structural components
- Can be pathologic or physiologic
Hypertrophy
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
- Hypertrophy of ____ organelles
- ____ show hypertrophy of (ER) in hepatocytes
- Increase amount of ____ to detoxify the drugs
- subcellular
- Barbiturates
- cytochrome P-450
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
- Increase in number of cells in an organ or tissue
- Usually resulting in increased mass of the organ or tissue
- Affects cells capable of dividing
- Can occur with hypertrophy, can be triggered by same stimulus
- Can be physiologic or pathologic
- Mechanisms: Result of growth factor–driven proliferation of mature cells
Hyperplasia
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
what are the physiologic hyperplasia
- Hormonal Hyperplasia – increases the functional capacity of a tissue when needed
- Compensatory Hyperplasia – increases tissue mass after damage or partial resection
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
- Most commonly caused by excess hormones or growth factors acting on target cells
- Ex: Endometrial Hyperplasia, Benign Prostatic Hyperplasia
Pathologic Hyperplasia
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
- Reduced size of an organ or tissue resulting from a decrease in cell size AND number
- Can be physiologic or pathologic
Atrophy
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
- Reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type
- It often represents an adaptive response in which one cell type that is sensitive to a particular stress is replaced by another cell type that is better able to withstand the adverse environment
Metaplasia
CELLULAR RESPONSES TO STRESS & NOXIOUS STIMULI
The most common epithelial metaplasia is?
columnar to squamous, as occurs in the respiratory tract in response to chronic irritation
AN OVERVIEW OF CELL INJURY AND CELL DEATH
Early stages or mild forms of injury; the functional and morphologic changes are reversible if the damaging stimulus is removed
Reversible Cell Injury
AN OVERVIEW OF CELL INJURY AND CELL DEATH
Continuing damage becomes irreversible; cell cannot recover and dies
Cell Death
AN OVERVIEW OF CELL INJURY AND CELL DEATH
Hallmarks of Reversible Injury:
1. reduced ____ ____ with resultant depletion of energy stores in the form of adenosine triphosphate (ATP)
2. ____ ____ caused by changes in ion concentrations and water influx
- oxidative phosphorylation
- cellular swelling
CELL DEATH: NECROSIS VS. APOPTOSIS
Characterized by:
- Severe damage to membranes
- Lysosomal enzymes enter cytoplasm and digest the cell
- Cellular contents leak out
Always a pathologic process
Necrosis
CELL DEATH: NECROSIS VS. APOPTOSIS
Characterized by:
1. Nuclear dissolution
2. Fragmentation of the cell without complete loss of membrane integrity
3. Rapid removal of the cellular debris
Serves many normal functions and is not necessarily associated with cell injury
Apoptosis
FEATURES OF NECROSIS AND APOPTOSIS
Cell Size: Enlarged (swelling)
Nucleus: Pyknosis, karyorrhexis, karyolysis
Plasma Membrane: Disrupted
Cellular Contents: Enzymatic digestion; may leak out of cell
Adjacent Inflammation: Frequent
Physiology or Pathologic Role: Invariably pathologic (culmination of irreversible cell injury)
necrosis
FEATURES OF NECROSIS AND APOPTOSIS
Cell Size: Reduced (shrinkage)
Nucleus: Fragmentation into nucleosome-size fragments
Plasma Membrane: Intact; altered structure, especially orientation of lipids
Cellular Contents: Intact; may be released in apoptotic bodies
Adjacent Inflammation: No
Physiology or Pathologic Role: IOften physiologic, means of eliminating unwanted cells; may be pathologic after some forms of cell injury, especially
DNA damage
Apoptosis
CAUSES OF CELL INJURY
What are the causes of cell injury
- Oxygen Deprication
- Physical Agents
- Chemical Agents and Drugs
- Infectious Agents
- Immunologic Reactions
- Genetic Derangements
- Nutritional Imbalances
Reversible cell injury is characterized by functional and structural alterations in?
early stages or mild forms of injury
which are correctable if the damaging stimulus is removed
REVERSIBLE CELL INJURY
what are the 2 feautes of Reversible Cell injury?
- Cellular Swelling
- Fatty Change
MORPHOLOGY OF REVERSIBLE CELL INJURY
the first manifestation of almost all forms of injury to cells
Cellular Swelling
ULTRASTRUCTURAL CHANGES IN REVERSIBLE CELL INJURY
what are the ultrastrucutal changes that take place in a cell injury?
- Plasma membrane alterations
- Mitochondrial changes
- Dilation of the ER, with detachment of polysomes; intracytoplasmic myelin figures may be present
- Nuclear alterations, with disaggregation of granular and fibrillar elements
- Denaturation of intracellular proteins and enzymatic digestion of the lethally injured cell; may take hours
- a pathologic process that is the consequence of severe injury
Necrosis
- characterized by denaturation of cellular proteins, leakage of cellular contents through damaged membranes, local inflammation, and enzymatic digestion of the lethally injured cell
- leakage of intracellular proteins through damaged plasma membranes and ultimately into the circulation is the basis for blood tests that detect tissue-specific cellular injury
Necrosis
MORPHOLOGY OF NECROSIS
What are the morphologic features of necrosis?
- increased eosinophilia
- glassy homogeneous appearance
- cytoplasm becomes vacuolated; appears moth-eaten
- myelin figures - whorled phospholipid precipitates derived from damaged cell membranes
- calcification of fatty acid residues results in the generation of calcium soaps - calcified dead cells
NUCLEAR CHANGES IN NECROSIS
Due to nonspecific breakdown of DNA:
- faded basophilia of chromatin
- loss of DNA due to degradation by endonucleases
Karyolysis