Cellular Injury Flashcards
What are the effects of stressors?
adaptive changes or exhaustion of or inappropriate adaptive efforts
How do you explain adaptive changes?
survival; maintain function
What happens when there is exhaustion of adaptive efforts?
start to see damage
What if the stimuli causing cellular injury stops?
with proper nutrition and oxygen the injury could reverse
What are the physical agents that cause cellular injury?
trauma, temperature changes, radiation, electrical stimulation
How does direct damage influence cells?
can result in cell rupture or damage to the cell membrane
What is an example of direct damage to a cell?
inflammation
How does local swelling influence cells?
It decreases micro-circulation to cells which decreases availability of oxygen and nutrients. Overall, it decreases healing.
What stimuli causes cellular injury?
physical agents, chemical agents, microorganisms, genetic defects, nutritional imbalances, hypoxia
What is an example of simple compound chemical agents?
glucose
What is an example of complex chemical agents?
toxins and therapeutic agents (chemotherapy)
What happens when chemical agents are taken into the cell?
they interrupt cell function or metabolism
What is an example of how microorganisms cause cellular injury?
cellulitis
What are the 3 ways microorganisms cause cellular injury?
- secretion of toxins
- interfere with metabolism
- viruses release viral proteins
How do viral proteins cause cellular injury?
they affect DNA
What are the 2 ways genetic defects contribute to cellular injury?
- inborn problems of metabolism
- gross malformations
What are gross malformations?
actual defect in DNA
How does low iron (a nutritional imbalance) contribute to cellular injury?
causes anemia
How does a high-fat diet (a nutritional imbalance) contribute to a cellular injury?
causes atherosclerosis
What are the 2 ways nutritional imbalances contribute to a cellular injury?
- deficiencies of vitamins and proteins primarily
- excessive food intake: especially lipids
What is the most common cause of cellular injury?
hypoxia
What is the term for inadequate oxygen in blood?
hypoxemia
What is the term for decreased oxygen to cells?
hypoxia
Inadequate oxygen in blood leads to decreased oxygen to cells which leads to…
decreased ATP generation
What action increases when there is a lack of oxygen in a cell?
anaerobic glycolysis
What are 2 results from the lack of oxygen in a cell?
- accumulation of lactic acid
- reduction in pH
What results from an accumulation of lactic acid?
metabolic acidosis
What results from a reduction in pH?
impaired enzyme processes
What are intracellular changes in response to stimuli?
inability of cell to process materials, lipid and carbohydrate accumulation, pathologic calcification, protein accumulation, pigments
What are 3 things that happen when the cell has an inability to process materials?
- accumulation in the cytoplasm
- metabolic processes slow (can’t make ATP)
- energy stores are depleted
What lipid if most often abundant in accumulation?
triglycerides
What 7 locations does lipid and carbohydrate accumulation occur?
- cytoplasm of parenchyma of certain organs
- intracellularly due to improper metabolism
- liver
- spleen
- CNS
- heart
- blood vessels
How does lipid and carbohydrate accumulation contribute to organ failure?
stimulates scarring of the organ or tissue
What disease is an example of lipid and carbohydrate accumulation?
Tay-Sachs disease, which is a genetic mutation, causes motor and neural degradation. It involves lipid accumulation in the brain.
What are 4 things that happen during pathologic calcification?
- impaired calcium homeostasis with cell membrane damage
- increased intracellular calcium released from mitochondria and endoplasmic reticulum
- activates potentially damaging enzymes
- causes organ dysfunction with increased uptake of calcium into injured cells
What 5 locations are most effected by pathologic calcification?
- skin
- soft tissues
- blood vessels
- heart
- kidneys
How does protein accumulation contribute to cell injury?
damage cellular organelles and disrupt cell function
What 2 locations is protein accumulation most evident?
kidneys and immune system
What are pigments?
colored substances that accumulate in cells
What are 3 examples of endogenous pigments?
- melanin
- hemoproteins
- hemosiderin
What is hemosiderin?
an iron-rich pigment that is the product of RBC destruction
What are 3 examples of exogenous pigments?
- carbon in lung tissue
- lead poisoning
- tattoos
What are the 3 main effects of disruption in cell membranes?
- impaired transport processes
- dysfunction of receptors
- free radical effects
What 4 things that happen because of impaired transport processes?
- cannot receive electrolytes
- failure of Na/K ATPase pump
- poor tissue defense
- bleeding disorders
What happens when there is failure of the Na/K ATPase pump?
-increased Na intracellularly
-increased K extracellularly
What happens when there is an increase in Na intracellularly?
there is a shift in extracellular fluid to the intracellular space which results in cloudy intracellular swelling and cell enlargement
What is the result of cell enlargement?
problems with electrical impulses necessary for nerve transmission, muscle contraction, active transport
What happens if the failure of the Na/K ATPase pump isn’t addressed?
eventually irreversible
Dysfunction of receptors occurs through (2):
- binding and destruction or blocking of receptors
- inappropriate triggering of responses or activity
What are free radicals?
unstable reactive chemicals
What are the 3 effects of free radicals?
- destruction of phospholipids in cell membranes
- damage to cell proteins
- DNA damage
What are the 5 types of cellular changes due to injury or stimuli?
- Atrophy
- Hypertrophy
- Hyperplasia
- Metaplasia
- Dysplasia
What are 4 causes of atrophy?
- aging
- disuse
- starvation
- cellular hypoxia/ischemia
What can occur because of hypertrophy?
can lead to heart failure and interrupt function
What is the cause of hypertrophy?
response to increase in workload = increased number of intracellular organelles
What is hyperplasia?
increase in number of cells
When/where does hyperplasia occur?
- in cells that are capable of dividing
- normal in pregnancy
What is metaplasia?
one adult cell type is replaced by another cell type
What 2 things happen because of metaplasia?
- chronic irritation and inflammation
- protective functions are lost
What is dysplasia?
cells have undergone atypical changes
Although dysplasia is presumably controlled,
it may transform into uncontrolled reproduction of cells
Is dysplasia reversal?
possible reversal with removal of irritation or stimulus
What are the 3 types of cell death?
- Apoptosis
- Necrosis
- Gangrene
What is apoptosis?
destroys cells that are no longer needed
(normal)
What happens if there is suppression of apoptosis?
there is a problem and is often associated with disease
What is necrosis?
cell death in a living organ or tissue
What do you do if a patient has necrosis?
the cells must be removed or it can be changed to nonfunctional tissue
What is gangrene?
a considerable mass of tissue undergoes necrosis
What can be the result of gangrene?
a lack of blood supply
(very severe)
