A/21 Flashcards
1
Q
What is hypertrophy?
A
Increase of cell size and functional capacity
2
Q
What generates hypertrophy?
A
- functional demand (mechanical trigger)
- hormones (trophic triggers)
- growth factors
3
Q
Cellular remodelling in hypertrophy (6)
A
- proteins not needed are degraded
- increased protein translation
- increased gene expression
- increased cell survival
- remodelling ECM
- increased DNA content (polyploidy)
4
Q
On which cells does hypertrophy act?
A
On cells that have a limited or no capacity at all to divide
5
Q
Example of hormone that causes hypertrophy
A
estrogen in pregnancy makes SMC in uterus produce more proteins
6
Q
2 pathways for hypertrophy
A
- PIP3 kinase / AKT pathway (physiological)
- G protein coupled (pathological)
7
Q
What is atrophy?
A
- reduction in size of an organ
- loss of cell matter
8
Q
Causes of atrophy (4)
A
- reduced functional demand
- inadequate O2 and nutrition supply
- interruption of trophic signals
- aging
9
Q
Mechanism of atrophy (4)
A
- protein synthesis decreases
- protein degradation
- decreased gene expression
- increased autophagy
10
Q
How does protein degradation happen in atrophy?
A
ubiquitin proteasome pathway (marked with ubiquitin)
11
Q
Examples of atrophy
A
- brown atrophy of the heart
- cerebral atrophy
- cahexia (causes osteoporosis)
