Cellular Adaptations Flashcards
What are cellular adaptations
Reversible changes in the size, number, phenotype, metabollic activity or function of cells in response to changes in the environment
Hypertrophy
Increase in size of cells that results in an increase in the size of the affected organ
Hypertrophy
As a result of physiologic response
Increase functional demand or stimulation by hormones and growth factors
Hypertrophy
As a result of pathologic response
Increased functional demand or stimulation secondary to pathological process
Hyperplasia
Increase in the number of cells in an organ or tissue in response to a stimulus
Hyperplasia
As a physiologic response
Action of hormones or growth factors when there is a need to increase functional capacity oh hormones sensitive organs
Hyperplasia
As a pathologic response
Caused by excessive or innapproriate actions of hormones or growth factors acting on target cells
Examples of physiological hyperplasia
Hyperplasia of bone marrow
Lymphoid hyperplasia
Regenerate hyperplasia
Hyperplasia of breast tissue
Examples of pathologic hyperplasia
Thyroid hyperplasia
Endometrial hyperplasia
Prostatic hyperplasia
What is atrophy
Reduction in size of an organ or tissue due to a decrease in cell size and number
Pathologic atrophy
Decreased workload Loss of innervation Diminished blood supply Pressure atrophy Infections Loss of endocrine stimulation
Cerebral atrophy
Gyri are narrowed and the intervening sulci are widened
Metaplasia
Reversible change in which one differentiated cell type is replaced by another differentiated cell type
E.g columnar to squomous l
Squamous metaplasia important sites
Bronchus
Endocervix
Bladder
Intestinal metaplasia
Occurs as a result of chronic gastritis or chronic peptic ulcerstion
