Chapter 4: Cell Injury, Aging, And Death Flashcards
Ischemia
most common cause of cell injury and injures cell faster than hypoxia alone
Hypoxia
causes power failure in the cell which is also caused by ischemia
Lactic Acidosis in Ishcemia
Cellular proteins and enzymes become more dysfunctional
When does cell death occur?
When plasma, mitochondrial, and lysosomal membranes are critically damaged
Hydropic Swelling
Cellular swelling due to accumulation of water
Why does hydropic swelling occur?
Malfunction of sodium-potassium pump with accumulation of sodium ions within the cell and also any injury that results in loss of energy(ATP).
What does cellular swelling look like?
Large, pale cytoplasm, dilated endoplasmic reticulum, and swollen mitochondria
Intracellular Accumulations
Accumulation of excessive amounts of normal intracellular substance, abnormal substances from faulty metabolism, and pigments or particles that the cell is unable to degrade
What are the nutritional injuries?
Nutritional deficiency and Nutritional Excesses
Nutritional Deficiency results from?
Poor intake, altered absorption, impaired distribution by circulatory system, and inefficient cellular uptake
Nutritional Excesses results from?
Excessive intake, BMI greater than 27kg/m^2 which can be considered a health risk or even obesity
Chemical Injury
Toxic chemicals or poisons can cause cellular injury both directly and by becoming metabolized into reactive chemicals by the body
What are the factors of physical and mechanical injury?
Extreme temperatures, abrupt changes in atmospheric pressure, mechanical deformation, electricity, and ionizing radiation.
Atrophy
Cells shrink and reduce their differentiated functions in response to normal and injurious factors
Causes of Atrophy
Disuse, denervation, ishcemia, nutrient starvation, interruption of endocrine signals, and persistent cell injury
Hypertrophy
Increase in cell mass accompanied by an augmented functional capacity in response to physiologic and pathophysiologic demands and caused by increased cellular protein content
Hyperplasia
Increase in cell number due to mitotic division
Causes of hyperplasia
Response to increased physiologic demands or hormonal stimulation and also due to persistent cell injury, chronic irritation of epithelial cells
Metaplasia
Replacement of one differentiated cell type with another
Causes of Metaplasia
Adaptation to persistent injury, with replacement of a cell type that is better suited to tolerate injurious stimulation. It’s also fully reversible when injurious stimulation is removed.
Dysplasia
disorganized appearance of cells because of abnormal variations in size, shape, and arrangement. It also gives a potential to transform into cancerous cells(pre-neoplastic lesions)
Necrosis
Consequence of ischemia or toxic injury or other injuries and is characterized by cell rupture, spilling of contents into extracellular fluid, and inflammation
What are the four types of tissue necrosis?
Coagulative, Liquefactive, Fat Necrosis, and Caseous Necrosis
Coagulative Necrosis (Heart)
Begins with ischemia and ends with degradation of plasma membrane