8. Non dividing cells
Physiological
Pathological
Cells not capable of replication
Mechanisms
mechanical triggers
trophic triggers
Ex :hypertrophy of heart
uterus in pregnancy
Skeletal muscle in body builders
9. Increased production of structural proteins
Switch of contractile proteins from adult to
fetal
Expression of fetal genes
11. Cells capable of replication
Increase in no of cells
Increase in size of the organ
Physiologic and pathologic
14. Shrinkage in cell size by loss of substances
Organ shrinkage
Physiologic or pathologic
Physiologic Atrophy
Ex : 1. Development – notocord , thyroglossal duct
2. uterus after parturition
15. Decreased workload
Loss of innervation
Diminished blood supply
Inadequate nutrition
Loss of hormonal stimulation
Senile atrophy
16. Imbalance between protein production and
utilization
Ubiqutin proteosome pathway
18. Reversible change
Replacement of one adult cell by other type
Mc – columnar to squamous
Seen in respiratory epithelium
Ducts of glands impacted by stones
Vitamin A deficiency
Malignant transformation on chronic stages
Barrets esophagus
Connective tissue metaplasia
Cervical metaplasia
19. Stem cell reprogramming
Uncoordinated growth factors
Vit A deficiency
Cytostatic drugs
Virus