Robbins Chapter 2 Flashcards
Hypertrophy
increase in cell size and thus increase in size of affected organ
No new cells, just larger cells.
In dividing cells, may respond to stress by
hypertrophy and hyperplasia
In nondividing cells, increase in mass comes from
hypertrophy
The most common stimulus for hypertrophy of muscle is
increased workload
During pregnancy, you get hormone induced
englargement of the uterus. Uterine hypertrophy stimulated by estrogenic hormones acting on smooth muslce through estrogen receptors. Leads to increase in smooth muscle proteins and an increase in cell size
Hypertrophy is the result of
increased production of cellular proteins (pink)
Hyperplasia is defined as
an increase in the number of cells in an organ or tissue in response to a stimulus
Hyperplasia is only able to occur
if cells are capable of dividing
Atrophy is defined as
reduction in the size of an organ or tissue due to a decrease in cell size and number
Causes of atrophy
Decreased workload (atrophy of disuse)
Loss of innervsation (denervation atrophy) loss of nerves
Diminished blood supply
Inadequate nutrition
Loss of endocrine stimulation
Pressure
Atrophy results from
decreased protein synthesis and increased protein degredation in cells
degredation of cellular proteins tends to happen by ubiquitin proteasome pathway
Metaplasia is
reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type
most often columnar to squamous
Metaplasia does not result from a change in the phenotype of already differentiated cells. Instead, it…
is the result of reprogramming of stem cells that are known to exist in normal tissues, or of undifferentiated mesenchymal cells present in the connective tissue
Two changes of reversible injury able to be seen under light microscopy
cell swelling
fatty change
(appearance of lipid vacuoles in the cytoplasm)
What is fundamental cause of necrotic cell death
ATP depletion
