6.13 Cell Adaptations Flashcards
(32 cards)
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.
What are examples of metaplasia?
- Squamous metaplasia of the bronchial epithelium due to smoking.
- Gastric or glandular metaplasia or GE junction in Barrett Esophagus.
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?
- Short lived or mild
- Cellular swelling or hydropic degeneration.
- No damage to nucleous
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?
- If acute stress to which a cell must react exceed its ability to adapt the resulting changes in structure and function lead to the death of a cell.
- Changes in the nucleus or by rupture of the cell membrane, or loss of cell integrity.
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.
