Mechanisms of Cell Injury Flashcards
Proteasomes
Degrades denatured proteins and releases peptides
Peroxisomes
Breakdown fatty acids and generates hydrogen peroxide
Cell polarity
The spatial differences in shape, structure, and function of cells
What is the role of the cytoskeleton?
- Responsible for cell movement
- Maintains cell shape and intracellular organization
- Can move organelles and proteins within the cell
What are the components of the cytoskeleton?
- Actin microfilaments
- Intermediate filaments
- Microtubules
Mitochondria
A regulator of apoptosis
Differential Diagnosis for cell injury
DAMN-IT-V
Most common causes of cell injury
- Oxygen deficiency
- Infectious agents
- Immunologic dysfunction
Anoxia
No O2 delivery to a tissue
What are some infectious agents that can cause cell injury?
- Viruses
- Bacteria
- Fungal
- Protozoan
- Metazoan parasites
Immune dysfunction example
Congenital defects: SCIDS (arabian foals)
What are the 6 major mechanisms of cell injury?
- Depletion of ATP
- Mitochondrial damage
- Loss of calcium homeostasis
- Accumulation of reactive oxygen-derived free-radicals
- Membrane damage
- Damage to proteins and DNA
The depletion of ATP can be due to what factors?
- Hypoxic injury
- Toxic injury ex: Cyanide
* *This is the fundamental cause of necrotic cell death due to irreversible mitochondrial and lysosomal membrane damage.
How far can ATP be depleted before its too much? Range?
Depletion of 5 to 10 percent is bad news bears
When there is mitochondrial damage what will be seen soon after?
- Formation of the MPTP (mitochondrial permeability transition pore)
- Production of ROS
- Activation of apoptotic pathways
