Lecture 34: Abnormal growth and differentiation Flashcards
What is adaptation defined as?
Defined as cellular changes in response to changes in environment or demand.
What might 5 changes from adaptation be seen in?
Cell size
Cell number
Cell phenotype
Metabolic activity
Cell function
Why would cells adapt?
Enables cells to survive as their environment changes, avoiding injury, reaching new metabolic steady state.
What 2 forms of adaptation are there?
- Physiological
- Pathological
Can adaptation be reversible?
Usually
What type of cells can adapt easily?
Labile populations with active stem cell compartments.
Give an example of a cell that can adapt easily?
eg. Epithelial cells
What type of cells cannot adapt easily?
Permanent population of terminally differentiated cells.
Give an example of a cell that cannot adapt easily?
Cerebral neurons
Give an example and why a cell may not need to adapt?
Some are inherently robust, not needing to adapt.
eg. Fibroblasts
How can cellular activity be increased?
Increasing the size or number of cells
How can cellular activity be decreased?
Decreasing the size or number of cells
What is hypertrophy?
increase in cell size
What is Hyperplasia?
increase in cell number.
What do both Hypertrophy and Hyperplasia result in?
Both result in increased mass of cells.
How does cell size increase in hypertrophy?
There is synthesis of more structural elements within the cell.
What does an increase in cell size lead to?
increased functional capacity of the cell.
Is hypertrophy physiological or pathological?
Can be both
In what type of cells is hypertrophy the most available mode of adaptation?
In cells with limited capacity for proliferation eg.skeletal and cardiac muscle.
What is Gravis Uterus?
induced hypertrophy of smooth muscle