cell adaptation yt

cell adaptation

Reversible changes of cell

• size

• number

• phenotype

• metabolic activity

• function

change their environment

types

hypertrophy

hyperplasia

atrophy

metaplasia

hypertrophy

increase cell size → organ/tissue increase size

no increase in number of cell

physiological/pathological

increased workload/hormone stimulation

Occurs in tissues that cannot divide, like:

• Cardiac muscle

• Skeletal muscle

hyperplasia

increase number of cell → cell divide/tissue or organ get larger

hormonal stimulation, increased functional demand, tissue repair

can lead to cancer if uncontrolled

atrophy

physiological (early dev) or pathological (generalized, localized)

decrease cell size → cell shrink/organ smaller

decrease protein synthesis, increase protein breakdown

Causes

• Disuse (bed rest, cast)

• Loss of nerve supply

• Poor nutrition

• Decreased blood supply

• Aging

• Loss of hormonal stimulation

metaplasia

one mature cell type is replaced by another mature cell

cause: chronic irritation or inflammation

can progress to dysplasia