Cell Growth and Adaptation Flashcards
Classification of cell growth and adaptation
- Congenital
- Acquired
- Abnormal
Congenital
Born with something (Aplasia, Hypoplasia)
Acquired
Hyperplasia, hypertrophy, atrophy, metaplasia. Adapted changes
Abnormal
Anaplasia, dysplasia, neoplasia
When do cells need to adapt
- dynamic changes during development
- Increased need for function
- Decreased need for function
Factors influencing cell growth and adaptation
- Cell microenvironment
- Physical or mechanical stressors on tissues and organs
- Genetic alterations of cells
Aplasia
Cells do not grow. See absence or partial absence of tissue always congenital
Hypoplasia
Decreased growth of cells. Incomplete or partial formation of a tissue or organ. Always congenital
Hyperplasia
Increase in the number of cells. Can be physiological such as in reproductive processes
Pathological hyperplasia
Increase in cell numbers and activity are detrimental to the animal. Such as in excessive proliferation during healing, bone loss from parathyroid hyperplasia. As well as put pressure on structures around it
Hypertrophy
Increase in the size of a cell. Can be physiological again in repro processes or skeletal muscles. Primarily happens in muscles
Pathological hypertrophy
Usually has same stimuli but if too excessive or inappropriate causes pathogenesis. Cardiac myocyte hypertrophy from CHF. Intestinal stenosis
Hyperplasia and hypertrophy
Often see concurrently because of demand for function, might see hyperplasia grossly and hypertrophy microscopically due to passing through cell cycle so fast
Atrophy
Decrease in size and or number of cells. In most cases the size and number go down. Can be physiological such as in repro processes
Pathological atrophy
Inappropriate loss of stimuli or inhibitory stimuli, such as skeletal muscles following denervation, bone loss from mineral imbalance etc
