Cellular Adaptations Flashcards
What is hypertrophy?
An increase in size of existing cells without cell division due to an increase in functional demand or from stimulation by hormonal or growth factors
Is hypertrophy reversible?
Yes
What is eccentric hypertrophy?
Where cells become longer
What is concentric hypertrophy?
Where cells become wider
What happens to nuclei in hypertrophied cells?
They become a lot larger
What mostly contributes to the increased size of hypertrophied cells?
Increased synthesis of structural components
What is hyperplasia?
An increase in the number of cells due to stimulation by hormonal or growth factors
Is hyperplasia reversible?
Yes
Where does hyperplasia occur in normal physiology?
in the endometrium during the reproductive cycle and in the breast during lactation
Do hyperplasia and hypertrophy ever occur together?
Yes e.g. in Grave’s disease
Why do some cells undergo hyperplasia and some cells undergo hypertrophy?
Depends on whether cells can divide or not - labile cells are continuously cycling, stable cells are in the G0 phase and permanent cells cannot divide so therefore cannot undergo hypertrophy
What is cellular atrophy?
When cells receive less than normal nutrients so decrease in size and activity - cellular components are removed by autophagy - reversible
What is tissue atrophy?
Where tissues reduce in size and activity due to cellular apoptosis - not reversible
When does physiological atrophy occur?
In the uterus after birth and in the thymus after adolescence
When does pathological atrophy occur?
inadequate nutrition, diminished blood supply, denervation, disuse, loss of endocrine stimulation, pressure
