Pathology 3- Cell injury Flashcards
Cell damage leads to
Tissue damage
Tissue damage leads to
Organism damage
What is Cell Injury? types?
When a cell fails to maintain normal homeostasis: Stress or injurious stimulus
-Reversible
-Irreversible
Cell/Tissue response to injury
Adaptation
Degeneration
Death: Apoptosis or necrosis
Reversible injury what is?
When a cell can undergo mild/transient injury that may be adaptable to return to normal
Irreversible cell injury
The point of no return.
Apoptosis
Necrosis
Ways the cell can adapt to change?
Hypertrophy
Hyperplasia
Metaplasia
Atrophy
What is hypertrophy? Characteristics?
Increase in cell size but not in number
-Synthesize more organelles (Ex. muscle growth)
- Reversible
- More appreciated on gross anatomy
Physiologic Example of hypertrophy
Most common in striated muscle.
- Working out, gain muscle mass but not increase in muscle cells.
Hypertrophic cardiomyopathy
Primary disease of myocardium
Common in cats
L ventricle is enlarged leaving very little lumen for the blood to flow from the muscle producing too many contractile elements.
Pathological example of hypertrophy
Occurs in response to disease
Ex: Pulmonic stenosis - Right ventricular myocardial hypertrophy
What is hyperplasia?
Increase in cell number
Cells that can undergo hyperplasia
Labile cells: epidermis, epithelium, bone marrow
Cells that can’t undergo hyperplasia
Permanent cells: neurons, cardiac/skeletal cells
Hyperplasia relation to hypertrophy
Usually concurrent with each other
Labile
Easily altered
Hyperplasia vs Neoplasia
Hyperplasia: Controlled increase in cell number
Neoplasia: Uncontrolled increase in cell number leading to disease
Physiological example of hyperplasia
Hormonal: Enlargement of pregnant uterus
Compensatory: Partial Lobectomy –> hyperplasia of liver cells.
Pathologic example of hyperplasia
excessive hormonal stimulation or chronic irritation
Goiter- thyroid hyperplasia
Which processes can increase the size of an organ of part of an organ?
Neoplasia, hypertrophy, inflammation, Hyperplasia
What is metaplasia? Is it reversible?
One differentiated cell type replaced by another
- Adaptive change for an organ or tissue better withstand injury
- Potentially reversible
Example of metaplasia
Smokers: Ciliated mucosal epithelium into stratified squamous epithelium
- Can withstand injury
What is atrophy?
Decrease in size of cell, tissue, or organ
- Occurs from decreased in cell number/size
- Happens after full maturation of organ
Physiologic example of atrophy
Involution: reduction in cell number through apoptosis
- Thymus
- Postpartum uterus
Pathological example of atrophy
Inadequate nutrition supply
- Starvation
-Decreased workload
- Denervation
- Pressure (benign neoplasm)
Atrophy vs Hypoplasia
Atrophy occurs in a fully developed tissue
Hypoplasia occurs when tissues never fully developed
