Adaptive Cell Reactions And Abnormal Accumulations Flashcards
Hypertrophy
Increase in the size of cells, organ
Larger cells
No new cells
Physiologic or Pathologic
Physiological Hypertrophy caused by
Increase functional demand
Stimulation by hormones or growth factors
Growth of uterus during pregnancy is a result of
Hormone-induced increase in the size
Hypertrophy of muscle fibers
Stimulated by estrogenic hormones acting on smooth muscle estrogen receptors ,
Pathological Hypertrophy
Increased workload
Metabolic demand increases
In the cells who have a limited capacity for division
Hypertrophy in the heart
Muscle cells synthesize more proteins and myofilaments
Hyperplasia
Increase in the number of cells in an organ or tissue
If the cell is capable of dividing
Physiologic or Pathologic
Relation between hyperplasia and hypertrophy
Frequently occur together
May be triggered by the same stimulus
*Distinct processes
Physiologic Hyperplasia types
Hormonal hyperplasia
Compensatory hyperplasia
Hormonal hyperplasia
Increase the functional capacity
Ex: Female breast at puberty
Compensatory hyperplasia
In individuals who donate
Remaining cells proliferate so that the organ can reach to its normal size
Pathologic Hyperplasia types
Endometrial hyperplasia
Benign prostatic hyperplasia
Which type of hyperplasia is a Common cause of abnormal menstrual bleeding
Endometrial hyperplasia
Pathological hyperplasia
Characteristics response to certain viral infections
Ex: HPV
Cancerous proliferation may eventually arise
Atrophy
Reduced size of an organ or tissue resulting from a decrease in cell size
Results from decreased protein synthesis and increased protein degradation in cells
Physiologic or Pathologic
Physiologic atrophy
During normal development
Embryonic structures
In infants — ductus arteriosus, fetal development
In adults— uterus size decrease after delivery
Causes of Pathologic atrophy
Decreased workload
Loss of innervation
Diminished blood supply— Ischemia
Inadequate nutrition
Loss of endocrine stimulation
Pressure
Metaplasia
One differentiated cell type is replaced by another cell type
Reversible
Most common epi metaplasia
Columnary to Squamous
In the respiratory tract
Response to chronic irritation
Mechanism of metaplasia
Result of a reprogramming of stem cells
Does not result from a change in the phenotype of an already differentiated cell type
Cytokines,growth factors
2 types of intracellular accumulations
1-Normal cellular constituents— water,lipid,proteins
2- Abnormal subs— exo or endo
Exogenous pigments
**CARBON
Tattoo
Endo pigments
Lipofuscin
Bilirubin
