what are the functions of the astrocyte
Found in bbb and is key in preventing pathogens from getting in
what is the function of microglia
able to supply surrounding cells with different neurotransmitters and release ATP for sourounding neuronal use
What 2 support cells have NMDA receptors
Astrocytes and microglia
What is the function of ann oligodendroglia and Schwann cells
oligodendroglia-mylein producing cells in the CNS
Schwann cells- mylein producing cells in PNS
What is saltatory conduction
conductance jumping bw nodes of ranvier to speed up conductance
What is MS
immune mediated destruction of mylein
What are one of the 1st s+s of MS +best way to diagnose
some degree of visual disturbance
MRI is gold standard
Hwo much energy does the na/k pump use daily
50% of ur total energy
if you allowed k or na do what it wanted what would be the eq of the cell
K- would likely leak out causing the cell to be more neg (-90)
na- would come in causing cell to be more positive (+50)
Conc of k, na and cl
K higher intracellularaly
na and cl higher extracellularly
Temporal vs spacial summation
temp- similarly timed signals will meet at hilock and add together to give a bigger signal
Spacial- signals close in space makes it more likely that these will act together
what is the threshold of most cells
-55mv
Where are most voltage gated sod channels
axon hillock
steps of depolarization
sod channels open causing shoot up to +30, then closes and repolarization happens.
voltage gated pot channels open and it leaves ccell (causing hyperpolarization)
What is hypocalcemia and hypercalcemia and what does it cause
hypo- less ca on outside of cell (causing inside to feel more positive; more excitable (can lead to cramping)
Hypercalcemia- more positive on outside (causing inside to feel more negative; less excitable
what happens in extreme increases in extracellular pot
cells will not be able to repolarize cuz there is way too much k outside cell so pot from inside wont leave at top of curve
what does tetrodotoxin do
Blocks volatage gated sodium channels
How does docking of vesicles occur
calcium activates docking
- synaptobrevin on neurotrasmitter vessicle attaches to sytaxin and SNAP 25 on membrane
- vesicle fuses and releases NT
