1.1 Growth Adaptations Flashcards
What is hypertrophy?
Increase in cell size
What is hyperplasia?
Increase in cell number
What are the two processes that underlie hypertrophy?
- Gene activation/Protein synthesis
- Production of organelles
True or false: hyperplasia and hypertrophy usually occur separately
False– usually together
Why is it that permanent cells such as the heart and brain cannot undergo hyperplasia?
They do not have stem cells–thus only hypertrophy
What are the three major permanent tissues in the body?
Cardiac myocyte
Skeletal muscles
Nerves
What is the classic example of physiologic hypertrophy?
Uterine expansion during pregnancy
What can pathologic hyperplasia progress to?
Dysplasia
Does BPH progress to cancer?
No
What are the two processes that underlie atrophy?
- Apoptosis of cells
- Decrease in cell size
What is the pathway the cells have to degrade cellular proteins (e.g. cytoskeletal)
Ubiquitin-proteasome pathway
What is the mechanism through which cells reduce the number of organelles?
Autophagy–degrade organelles via lysosomes
What is the underlying process of metaplasia?
Change in cell stress leads to a change in cell type to better handle the stresses placed upon it
What type of cells most often undergo metaplasia?
Surface epithelium
What is the classic example of metaplasia?
Barrett’s esophagus–goes from squamous to columnar epithelium with goblet cells