Lecture 12 Flashcards
Necrosis
“accidental cell death”
does not require signaling and gene expression
cell swelling
cell lyses and bursts, spilling contents
inflammation
Apoptosis
"cell suicide" requires signaling and gene expression cell shrinkage cell fragments into apoptotic bodies no inflammation
The way hypoxia kills neurons (necrosis)
Energy defect
lactic acidosis
energy deficit
lack of oxygen disrupts energy production
lactic acidosis
build up of lactic acid from anaerobic metabolism, low pH kill s cells
The way hypoxia kills neurons (apoptosis)
Oxidative stress
glutamate excitotoxicity
inflammation
oxidative stress
buildup of metabolic intermediates due to abnormal ATP prodution in the absence of oxygen that damage DNA proteins and membrane
glutamate exitotoxicity
hypoxic neurons release excess amounts of the neurotransmitter glutamate, which causes huge Ca2+ influx into postsynaptic neurons which triggers apoptosis
inflammation
immune cells can also accidentally damage and kill neurons by releasing substances that trigger apoptosis
Does apoptosis cause inflammation
NOOOOOOOO but inflammation can cause apoptosis
HOw does cerebrovascular disorders injure and kill neurons
Crushing and compression of neurons by bleeding hematoma
hypoxia
crushing and compression of neurons by bleeding hematoma
causes death by necrosis occurs in cerebral hemorrhage only
hypoxia
lack of oxygen in “downstream” neurons due to lack of blood flow causes both necrosis and apoptosis, occurs in both cerebral hemorrhage and cerebrovascular occulsion
Different types of brain tumors
glioma
secondary metastases
primitive neuroectrodermal tumor PNET
Meningioma
Glioma
glial cell tumor, very aggressive often found in adults
secondary metastases
tumor that form elsewhere in the body invade into the brain from the bloostream , very aggressive, typically found in adults
primitive neuroectodermal tumor
very aggressive neuroblastic tumor in young children
