Cellular Adaptation, Injury, and Death Flashcards
Injury or stress to cells is:
Adaptation
Increase in cell demand is:
Hypertrophy
Decreased stimulation or lack of nutrients in cells is:
Atrophy
Chronic irritation in cells is:
Metaplasia
List the 4 cellular adaptations:
- Hypertrophy
- Hyperplasia
- Atrophy
- Metaplasia
Define Hypertrophy:
Increase in the size of the cells result in increased size of the organ (may be physiologic or pathologic)
What are examples of physiologic hypertrophy?
- Increased workload (ex. cardiac and skeletal muscle)
2. Hormone induced (pregnant uterus)
Define Hyperplasia:
Increase in the number of cells results in increase in the size of the organ. (may be physiologic or pathologic)
What are examples or physiologic hyperplasia?
- Hormonal hyperplasia (female breast and puberty/pregnancy)
- Compensatory hyperplasia (unilateral nephrectomy and liver regeneration)
- Erythroid hyperplasia of bone marrow (Chronic hypoxia: high altitude stays, chronic lung disease, and cyanotic heart defects)
What are examples of PATHologic hyperplasia?
- Excessive hormone stimulation (endometrial hyperplasia and prostatic hyperplasia)
- Viral infections (papilloma virus [warts])
- Side effects of drugs (gingival hyperplasia)
Define atrophy
Reduced size of an organ due to a decreased size an number
List examples of atrophy:
- Physiological atrophy (notochord-differentiates into spine in fetal development)
- Post partum uterus
- Pathologic atrophy (local or generalized - neuromuscular disorders)
Causes of Atrophy are:
- Decreased work load (disuse atrophy and stroke)
- Loss of innervation (denervation atrophy and amyotrophic lateral sclerosis)
- Diminished blood supply (ischemia)
- Inadequate nutrition
- Loss of endocrine stimulation (menopause)
- Pressure (enlarged benign tumor)
- Aging (senile atrophy)
Define metaplasia:
Reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type// usually responds to stress or chronic irritation
List causes and examples of metaplasia:
- Tobacco smoke (squamous metaplasia in the respiratory tract *most common)
- Gastric acid reflux (gastric metaplasia of distal esophagus and Barrett esophagus)
- Related skeletal muscle injury with hemorrhage (muscle replaced by bone and myositis ossifications)