Cell Response And Injury Flashcards
Atrophy
Cells decrease in size. The mechanism is adaptive and reversible. Cause by Disuse, Denervation, Loss of Endocrine stimulation (Vaginal Atrophy) , poor nutrition, and Ischemia. Effect is that cells components are reduced in size.
Ischemia
Decrease blood flow to a body organ due to obstruction of a blood vessel.
Hypertrophy
Cells Increase in size. Common in cells that cannot undergo mitosis. This mechanism is adaptive and reversible.
Physiologic Hypertrophy
Results of a normal physiological process upon increase workload (EX. when a person works out)
Pathologic Hypertrophy
Result of a disease.
Adaptive is an enlargement due to increase functional demands (Ex Left-ventricular Hypertrophy)
Compensatory is an enlargement of a remaining organ or tissue after a portion was removed (Ex kidney removed)
Hyperplasia
An Increase of number of cells. This can also occur with Hypertrophy. This mechanism is adaptive and reversible.
Physiologic Hyperplasia
Hormonal is breast and uterine enlargement during pregnancy (Ex Estrogen)
Compensatory occurs after damage or resection. (Ex. Wound healing)
Nonphysiologic Hyperplasia
Excessive hormonal or growth factor stimulation (Ex Bening Prostatic Hyperplasia)
Metaplasia
One type of cell is replaced by another type. Usually a response of chronic irritation and inflammation. Smoking can induce metaplasia.
Dysplasia
Disorganized cell growth. Loss of differentiation. It is a precursor of cancer.
Intracellular accumulations
Buildup of substances that cells cannot immediately use or eliminate. (Ex. Normal Body Substance, Abnormal endogenous product, and Exogenous Product)
Fatty Liver (Steatosis)
Abnormal accumulation when the delivery of free fatty acids to the liver increased or when the intrahepatic metabolism of lipids is disturbed.
Jaundice (“ictericia”)
Imbalance between synthesis and clearance of bilirubin. (Accumulation of bilirubin)
Foam cells in atherosclerosis
Atherosclerotic plaque that obstructs the blood flow (Ischemia)
Pathologic Calcifications
A lesion in which calcium salts are deposited abnormally in soft tissues.
Dystrophic Calcification
-Occurs in dying and dead tissue
-Calcification extra and intracellular
-Typically a localized lesion
-Could lead to organ dysfunction
Metastatic Calcification
-Occurs in normal tissue
-Calcification extracellular
-Hyperparathyrodism, Vitamin D intoxication, and Diseases with extensive destruction of bone.
Cell Injury
Damage in the cell usually reversible.
Mechanisms:
-free radical formation
-Hypoxia and ATP depletion (Increase in sodium and decrease of ATP)
-Increase in intracellular calcium
Free radical formation
They react with proteins, membranes, and DNA creating damage.
They are eliminated through antioxidants.
Hypoxia and ATP depletion
Less oxygen interrupts the ATP production. Reduced ATP makes sodium to accumulate inside the cell and cause cell swelling. Allows diffusion of enzymes, proteins, etc.
Disruption of intracellular calcium homeostasis
Serve as reference when cells are injured. Signals for apoptosis.
Apoptosis
-Programmed cell death
-Physiological or pathological process
-It starts through cell signaling, then shrinks its compartment. Cell is divided in apoptotic bodies and phagocytic cells eliminate them.
Necrosis
-Not programmed cell death in an organ or tissue that is still part of a living person.
-Pathological process
-Unregulated enzyme digestion
Liquefaction necrosis
Cells die but their catalytic enzymes are not destroyed. (Pus)
