cell injury
Terms
undefined, object
copy deck
- What are two strategies for restoring blood flow after stroke?
- thrombolysis (w/i 2 hours) and maintenance of the brain perfusion pressure
- What are 4 ways to decrease energy demands of the brain after stroke to prevent more neuronal death?
- hypothermia (not pratical), sedation, reduction of the production of action potentials, and inhibition of excitatory synaptic transmission.
- What are three mechanisms for blood brain barrier breakdown?
- excitotoxicity (via glutamate), decrease in glucose thus decrease in ATP(loss of ion balance), and inflammation
- The leader sequence on proteins destined for mitochondria has what kind of sequence?
- basic amphipathic amino acids
- How does complex II of the ETC (succinate dehydrogenase) accomplish ischemic preconditioning?
- it is a K+ channel that allows influx of K+ that results in a short period of ischemic symptoms that can protect the heart from longer sustained ischemia later.
- What ETC complexes are most important for making ROS?
- Complex I and complex III
- During ischemia, the primary trigger for cellular pathology is...?
- ATP depletion
- During ischemia, ATP depletion causes three events that facilitate amplification of cell damage. What are they?
- increase of lactic acid, increase Calcium release into cell, and anoxic depolarization (excitotoxicity)
- Why does glutamine remain in the synaptic cleft after ischemia thus causing neuronal excitotoxicity?
- Glutamine is usually clered by an ATP dependent process, that is disrupted in ischemia due to decrease in ATP.
- How does excitotoxicity cause cell injury?
- It opens ion channels (specefically calcium) thus there is an influx of calcium, sodium, chloride and efflux of potassium. Many enzymes are stimulated and the membrane is damaged.
- What is the big difference between apoptosis and necrosis?
- Necrosis leads to "cell leaking" and inflammation while apoptosis leads to phagocytosis
- Describe the extrinsic death pathway in apoptosis via Fas.
- FasL causes trimerization of Fas, then three FADD's bind and activate caspase 8.
- Describe the intrinsic death pathway in apoptosis.
- Cytochrome C is released from the mitochondria and combines with APAF-1 (several of each combine) and thus activate caspase 9.
- Cells in the ischemic core undergo this process... while the surrounding cells in the penumbra undergo this process...
- necrosis in the core and apoptosis in the penumbra
- Chronic inflammation and abscesses always lead to this...
- fibrosis (scarring) which is loss of tissue function in that spot
- chronic inflammation can occur in response to what (3 things)?
- persistant infections, prolonged exposure to toxic agents, and autoimmune disease
- What are the four morphological patterns of inflammation?
- serous inflammation (blister), fibrinous inflammation, suppurative/purulent inflammation, and ulcers
- what are ways to stimulate neurogenesis after stroke?
- stem cells, cord blood, statins, NO donors, growth factors, and cytokines.
- During angiogenesis, what event is absolutely important for stabilazation of the vasculature and for homeostasis?
- extracellular matrix remodeling.