Define Cellular Adaptation
Prolonged exposure of cells to adverse or exaggerated normal stimuli, which evokes various changes at the level of individual cells, tissues or whole organs. Once the cause is removed, most cells that have adapted to chronic stimulation revert to normalcy once again.
What is Atrophy?
Decrease in the size of tissue organ or the entire body.
What is a physiologic example of atrophy?
Thymus undergoing involution. Ovaries, uterus, and breasts after menopause. The atrophic bones and muscles in the elderly become thin and prone to fracture.
What is a pathologic example of atrophy?
- Ischemic organs are typically small, such as kidneys involved with atherosclerosis, testicular atrophy.
What is Hypertrophy?
An increase in the size of tissues or organs due to enlargement of individual cells.
What is Hyperplasia?
An adaptive increase in the number of cells that can cause enlargement of tissues or organs.
Examples of Hyperplasia
- Hyperplastic polyps of the colon or stomach
What is Metaplasia?
An adaptive change of one cell type for another to suit the environment
What is Dysplasia?
Best Example of Dysplasia
The best example is detection of cervical dysplasia (cervical intraepithelial neoplasia or CIN) based on PAP smears.
What is Anaplasia?
- Hallmark of malignant transformations.
What are other names for Anaplasia?
What is an example of Physiologic Hypertrophy?
Enlargement of skeletal muscles in body builders due to weights
What is an example of Pathologic hypertrophy?
Hypertrophy of the heart that occurs as an adaptation to increased workload. Concentric hypertrophy of the left ventricular muscle is typically seen in hypertension.
What is an example of both hyperplasia and hypertrophy?
What are examples of metaplasia?
What is Dysplastic vs anaplastic tissue?
Dysplastic-precancerous
Anaplastic- Cancer
What are the microscopic hallmarks of anaplasia
1) The cells and the nuclei display marked cellular pleomorphism.
2) The nuclei are irregular and hyper chromatic.
3) high N/C ratio
4) arge nucleoli present in nucleus.
5) Large number of abnormal mitotic figures
What is reversible cell damage?
What is the best example of reversible cell damage?
Hypoxia causes dysfunction of the ATP driven Na/K pumps altering the permeability. once ATP function is restored the Na+ and the water are pimped out of the cell.
What is irreversible cell damage?
What is pyknosis?
condensation of the chromatin
What is Karyorrhexis?
Fragmentation of the nucleus into small particles (nuclear dust)
What is Karyolysis?
Involves dissolution of the nucleus and lysis of chromatin by enzymes.