6.13 Cell Adaptations Flashcards
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?
- Best example Alzheimer’s, frontal brain shrinks.
- 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
- Endometrial hyperplasia due to estrogens.
- 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?
- Disordered growth of tissues resulting from chronic irritation or infection.
- Precancerous
Best Example of Dysplasia
The best example is detection of cervical dysplasia (cervical intraepithelial neoplasia or CIN) based on PAP smears.
What is Anaplasia?
- Undifferentiated and uncontrolled growth of cells.
- Hallmark of malignant transformations.
What are other names for Anaplasia?
- Malignancy
- Carcinoma
- Cancer
- Neoplasm
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?
- May occur together under a variety of conditions:
- Physiologic hypertrophy of the uterine smooth muscle cells during pregnancy is also accompanied by hyperplasia.
- Hyperplastic prostate, BPH increase both the size and number of glands and stroma.