Cell Injury (General/Reversible) Flashcards
O2 deficiency, physical agents, infectious microbes, nutritional imbalances, genetic derangement, workload imbalance, chemicals/drugs/toxins, aging, and immunologic dysfunction are all causes of…
Cell injury
Acute cell swelling is ___________ cell injury
Reversible
Oncotic necrosis and apoptosis are both ______________ cell injury
Irreversible
What is cell injury?
Anything that disrupts cellular homeostasis
What are the 6 biochemical mechanisms activated by cell injury?
- ATP depletion
- Permeabilization of cell membranes
- Mitochondrial damage
- Loss of Ca homeostasis
- Oxidative stress
- Damage to DNA (usually irreversible)
What are the 3 types of responses to cell injury?
- Degeneration (reversible)
- Death (irreversible)
- Adaptation (change to adapt to injury)
A state in which oxygen is not available in sufficient amounts at the tissue level to maintain adequate homeostasis
Hypoxia
Reduction of vascular perfusion
Ischemia
Inadequate oxygenation of blood may occur during…
Cardiac/respiratory failure
Anemia and carbon monoxide poisoning are associated with __________ O2 transport by RBCs
Reduced
Cyanide toxicosis ___________ the respiratory enzymes of a cell
Inhibits
What are some physical agents that cause cell injury?
Mechanical trauma, electric shock, temperature extremes (heat-stroke/frostbite)
Painful condition of the feet caused by long immersion in cold water or mud, and marked by blackening and death of surface tissue due to prolonged vasoconstriction
What are some infectious microbes that cause cell injury?
- Bacteria (Endo/exotoxins)
- Viruses
- Fungi
- Parasites
A toxin released into blood circulation by a bacterial cell, leading to distant tissues being affected
Exotoxin
(Example: E. Coli)
A toxin that is present inside a bacterial cell and is released when the cell disintegrates
Endotoxin
(Example: Salmonella)
What are two examples of viruses that cause necrosis in cells?
- Herpes simplex encephalitis (necrosis in the brain)
- Parvovirus (necrosis in the GI tract)
What are some examples of fungi that cause cell injury?
- Streptococcus (lesions in the brain)
- Micotic Rhinitis (leads to necrosis in nasal mucosa)
What are some examples of parasites that cause cell injury?
- Hookworm (anemia, hemorrhage in GI tract)
- Ear mites (proliferate in epidermis, increase in keratin)
What are 3 categories of nutritional imbalances?
Deficiencies, excesses, and imbalances
A disease characterized by vitamin D deficiency that is common in young animals; affects growth plates, often resulting in small stature, and causes bones to be softer
Rickets
A condition affecting the rumen caused by grain overload; overproduction of lactate; results are hemorrhage and necrosis of the rumen
Ruminal acidosis
What deficiency causes nutritional myopathy in livestock?
Vitamin E and selenium
What is the result of a PKD-1 and/or PKD-2 gene mutation in Persian cats?
Polycystic Kidney Disease
These genes are responsible for tubule development, and mutation causes excessively dilated tubules
What are some general consequences of genetic mutations?
- Production of abnormal protein
- Production of defective enzymes
- Lack of necessary enzyme
- Neoplasia
Hypertrophy of muscle in weightlifters, and myocardial hypertrophy secondary to valvular stenosis are both examples of…
(Hint: think workload imbalance)
Overwork or overstimulation
Disuse atrophy, denervation atrophy, and lack of endocrine stimulation are all examples of…
(Hint: think workload imbalance)
Underwork or lack of stimulation
Snakebites possess a toxin that targets ___________ cells, causing swelling and hemorrhage
Endothelial
Chemicals, drugs, and toxins cause cell injury by… (3 answers)
- Binding receptors
- Inhibiting/inducing enzymes to alter metabolic pathways
- Producing free radicals
What does mycotoxin (Moldy Corn Poisoning) do to the brain?
Causes necrosis of the white matter (leads to depression and blindness)
The toxic chemical products of fungi that readily colonize crops - capable of causing disease and death
Mycotoxin
Immunologic deficiencies, allergies/hypersensitivities, and autoimmune diseases are all categorized as types of…
Immunologic dysfunction
Inflammation of the skin, often caused by ingestion of or direct skin contact with an allergen
Atopic dermatitis
Autoimmune disease that affects desmosomes in the epidermis and is characterized by painful skin blistering
Pemphigus
Cumulative damage to DNA predisposes tissue to ________.
Neoplasia
The initial response of a cell to perturbation of homeostasis; reversible if injury is not too severe or prolonged
Acute cell swelling
Hydropic degeneration, ballooning degeneration, and cytotoxic edema are all alternative terms for…
Acute cell swelling
True or False: Glycolysis does not require O2 to produce ATP, but ETC and oxidative phosphorylation do require O2
True
ATP depletion leads to widespread __________ of sub cellular systems
Failure
What sodium/potassium and calcium abnormalities (as a result of ATP depletion) directly cause acute cell swelling?
(Hint: think in terms of increase/decrease)
Increased intracellular Na, H2O, and Ca, and decreased K
What are some consequences of increased intracellular Ca?
Increased enzyme activation:
- ATPase (which degrades ATP)
- Endonuclease (which damages DNA)
- Protese (which damages cell structural proteins)
- Phospholipase (which damages membrane phospholipids)
Hypoxia, toxic agents, increased levels of cytosol ihc calcium, oxidative stress, and phospholipid breakdown are all injurious agents that can lead to…
Mitochondrial damage
What does mitochondrial damage lead to (in terms of ATP and ROS)?
Decreased ATP production and increased ROS production
Lipid peroxidation, protein modifications, and DNA damage are all effects of…
ROS
Antioxidants that block formation of ROS or scavenge (sacrifice themselves)
Vitamins A, C, E, and selenium
Antioxidants that partake in sequestration of inducing agents for ROS (transport proteins for copper and iron)
Ferritin and ceruloplasmin
Enzymes which decompose H2O2, OH, and O2-
Catalase, superoxide dismutases (SOD), and glutathione peroxidase
Tissue damage caused when blood supply returns to tissue after a period of ischemia or lack of O2 (anoxia or hypoxia)
Ischemia-reperfusion injury or reoxygenation injury
(Extra note: especially relevant for torsion cases!)
What are the 4 mechanisms for reperfusion injury?
- Oxidative stress (ROS)
- Intracellular calcium overload
- Inflammation
- Activation of complement system
Name the category of cell swelling morphology:
Generalized swelling of cell + organelles (especially mitochondria), plasma membrane blabbing, ribosomal detachment from ER, nuclear chromatin clumping, and myelin figures
Ultrastructural
Name the category of cell swelling morphology:
Pale, eosinophilic, and finely vacuolated cytoplasm; swollen cells
Microscopic
Name the category of cell swelling morphology:
Increases volume/weight of organs (if diffuse), imparts pallor, swollen and rounded edges on organ
Macroscopic/Gross
