Cell Adaptations: Intracellular & Extracellular Accumulations Flashcards
Atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia are all ways cells may __________ to sub lethal injury
Adapt
Decreased size and/or number of cells after reaching normal size; decrease in number and size of organelles
Atrophy
Tissues or organs that are smaller than normal because they never developed completely
Hypoplasia
What are apoptosis and autophagy?
Mechanisms of atrophy where cells consume their own damaged organelles as a housekeeping function to remain alive
What are some factors that cause atrophy? (Multiple answers)
- Nutrient deprivation (lack of adequate blood flow)
- Loss of hormonal stimulation
- Decreased workload (disuse atrophy)
- Denervation (especially in skeletal m.)
- Compression (adjacent to neoplasms or other masses)
What is adrenocortical atrophy, and what does it cause?
Destruction (atrophy) of the adenohypophysis that causes a loss of hormonal stimulation
Increase in size and volume of a tissue or an organ due to increase in cell size; increase in size or number of organelles; caused by increased workload
Hypertrophy
Why are heart and skeletal muscle prone to hypertrophy?
Their cells are post-mitotic and incapable of replication
Increase in the number of cells; can only occur in cell populations capable of mitosis; subsides if stimulus removed
Hyperplasia
What are some causes and examples of hyperplasia?
- Hormonal stimulation (mammary glands & endometrium during lactation/gestation)
- Iodine deficiency (thyroid hyperplasia/goiter)
- Idiopathic (modular hyperplasa in spleen, liver, or adrenal cortex in older dogs)
Change of cell type of the same germ line (such as squamous epithelial to columnar epithelial); can be a protection mechanism responding to chronic injury, but may be pre-neoplastic
Metaplasia
What happens during squamous metaplasia of the trachea and bronchi and smokers?
Loss of cilia/goblet cells, leading to a decrease in mucocilliary clearance capabilities
Squamous metaplasia of mucosal glands occurs as a result of which type of deficiency?
Vitamin A deficiency
Intestinal metaplasia of the esophagus that predisposes the animal to an esophageal tumor (caused by chronic regurgitation)
Barrett’s esophagus
An abnormality in the formation of a tissue; when applied to epithelium, implies disorganized cells varying in size and shape, with nuclear pleomorphism and increased mitotic figures; pre-neoplastic, induced by chronic injury
Dysplasia
Lipids, glycogen, proteins, viral inclusion bodies, and lead inclusions are all _____________ accumulations
Intracellular
Amyloid, fibrinoid change, cholesterol, and urate tophi (gout) are all ______________ accumulations
Extracellular
Accumulation of lipids within parenchymal cells; very common in the liver
Lipidosis (steatosis)
Normal lipid metabolism consists of uptake, catabolism, and secretion, but what happens if there is a defect in one or more of these steps?
Lipid accumulation
Starvation in overweight animals, high fat diet, and diabetes mellitus are all causes of…
Hepatic lipidosis due to increased delivery of fatty acids to hepatocytes
Suppression of fatty acid oxidation (via hypoxia/other cell injury) and suppression of apoprotein synthesis and impaired release of lipoproteins from hepatocytes (via toxins) are both causes of…
Hepatic lipidosis caused by decreased mobilization of lipids from hepatocytes
What is the general gross appearance of a liver affected by diffuse hepatic lipidosis?
Swollen (high rupture risk), yellow, greasy/friable texture
What is the microscopic appearance of hepatic lipidosis?
Swollen hepatocytes, sharply defined vacuoles, nucleus displaced to periphery
Stored in hepatocytes and skeletal muscle; accumulates during metabolic abnormalities (such as diabetes mellitus and canine hyperadrenocorticism)
Glycogen
