Flashcards in Cellular Adaptions Deck (17):
Examples of when insoluble signals might be used
1. Anchoring to stromal elements (ECM)
2. Anchoring to other parenchymal cells and organizing components (BM)
3. Adherence to adjacent, migrating cells
4. Adhesion molecules give signaling + Anchorage
What are labile cells?
Examples of labile cells
Skin/Hair, GI, and Resp. Epithelial Cells, Stem Cells
What are quiescent or stable?
Cells that divide only in situation of stress or repair
Examples of quiescent tissues?
glandular tissues, liver cells, stromal cells, smooth muscle cells, endothelial cells, renal tubular epithelium
Examples of cells that don't divide in adulthood
Cardiac muscle, skeletal muscle, nerve cells
Examples of physiologic hypertrophy
Increased muscle mass with exercise, growth factors, hormonal activity (uterus in pregnancy)
Examples of physiologic hyperplasia
Growth under normal hormonal control (lactation, menstrual cycle, puberty)
Examples of pathologic hypertrophy
Abberant hormone secretion, cancers
What is compensatory hyperplasia?
Replacement of lost tissue due to resection or necrosis (cell death), allowing cell proliferation to occur, but not increasing the overall size of the tissue.
What is atrophy?
Reduced size of organ or tissue from a decrease in cell size.
What is apoptosis?
Loss of cells through programmed cell death
What is hypoplasia?
Too little division -- developmental defect in which a tissue fails to develop to normal size due to tissue failure to divide
What is aplasia?
Developmental defect in which a tissue fails to develop at all due to absence of a primordium
What is metaplasia?
Reversible change in which one adult cell type is replaced by another adult cell type.
Usually an adaptive response to chronic stress.
What is dysplasia?
A disordering of the tissue architecture characterized by loss in the uniformity of the individual cells as well as a loss of their architectural orientation.