Growth Adaptations Flashcards
What are the 3 permanent tissues in the body which therefore can only undergo hypertrophy (and not hyperplasia)?
- Skeletal muscle
- Cardiac muscle
- Nerve
What is an example of tissue hyperplasia which can progress to dysplasia and cancer?
Endometrial hyperplasia
What is an exception to the rule of hyperplasia leading to dysplasia and therefore cancer?
Benign prostatic hyperplasia
What is atrophy?
- Decrease in stress leading to a decrease in organ size
- Occurs via a decrease in the size and number of cells
What are the 3 mechanism whereby atrophy occurs?
- Apoptosis - decrease in cell number
Decrease in cell size:
- Ubiquitin-proteosome degradation of the cytoskeleton
- Autophagy of cellular components
What is metaplasia?
Change in stress on organ leads to change in cell type
What does metaplasia occur via?
Reprogramming of stem cells
Is metaplasia reversible?
Removal of the driving stressor
Metaplasia exception to the rule that it leads to dysplasia?
Apocrine metaplasia
- Does not incr risk for cancer
What vitamin deficiency can lead to metaplasia?
Vit A
What is Keratomalacia?
Metaplasia of conjunctiva - thickening
- Due to vit A deficiency
What is vit A responsible for?
Proper maturation of cells in the immune system
15 17 translocation leads to what disease?
Acute promyelocytic leukemia
- Cells accumulate in blast state
What receptor is affected in 15 17 translocation?
Vit A (retinoic acid) receptor
What is myositis ossificans?
Bone within skeletal muscle
- metaplasia
- Often after trauma
