How cells adapt to the altered environment in disease (self directed) Flashcards
What is hypertrophy
Increase in size of tissue because of glycogen storage or increase in myofibril size
What is hyperplasia
Increase in size of tissue/organ because of increase in reproduction rate of its cells
What is metaplasia
Change in the type of tissue present
What is fibrosis
Change in type of tissue because of healing/scarring
What is neoplasia
Malignant
If there’s an increased functional demand, what can be done? What may cause this?
Hypertrophy- increase cell size
Hyperplasia- increase in cell number
Example of hypertrophy and hyperplasia
Hypertrophy- increase in myosotes (muscle cells) when exercising
Hyperplasia - Increase in number of cells in endometrium (lining of uterus)
how does hypertrophy come about
- Increased production of growth factors
- In disease, cell adaptations are controlled by action of growth factors linking to nuclear transcription factors via second messenger systems
What is the cell stress response
Allows checks to survive pathological stimuli
- housekeeping genes switched off
-cell stress genes switched on
Cell stress proteins are expressed in cells
Cell stress proteins are cytoprotective
Example pf cell stress protein and what it does
Ubiquitin
- misfolded proteins detected
- ubiquitin activated
- ubiquitin ligated onto protein
- protein then targeted by proteasome system
- Protein becomes degredated
what’s cell atrophy
Cell components removed b degradative systems
- cytosolic proteolysis; ubiquitin system
- Autophagy; damaged organelles removed from cell
What’s lipofuscin
Remains as a result of autophagy and is brown
Process of autophagy
- Faulty organelle enveloped by ER derived membrane
- Lysosome fuses with early autosomal body and releases lysozyme
- Hydrolysis
- Recyclable stuff diffuses out
- Non recyclable stuff stays put (e.g. lipofuscin)
Stages of apoptosis
- Cells lose contact an round up
- Nuclear condensation
- Cell undergoes fragmentation to form apoptotic bodies
- Apoptotic fragments recognized by local cells and phagocytes are internalized and degraded
What is apoptosis controlled by
Caspases (protease)
