General Neurophysiology iBook Flashcards
in the case of acidosis the firing rate of chemoreceptors will ___ and in alkalosis the rate will __
increase, decrease
kidney has 2 types of intercalated cells that use carbonic anhydrase reaction
Type A secretes ___
Type B secretes___
A = H+ B = HCO3-
acidosis activates which type of intercalated cells?
type A bc secretes H+ into tubule
-bicarb absorbed
CO2 can enter the CSF then what
if one is chronically high on CO2, CSF will be too ____
-cells making CSF will make and add ___ to CSF while pumping the ____ ion made to ____
acidic
HCO3-
H+ ion made to the blood
what enzyme does the choroid plexus have
carbonic anhydrase
what happens to the pH of the CSF if a patient is suffering from metabolic acidosis?
nothing because H+ ions cannot cross BBB
CSF pathway
from ventricle–> through foramens of Magendie and Luschka —> to subarachnoid space
what is another way CSF is taken up by arachnoid villi
pinocytosis by mesothelailal cells of arachnoid villi
-remainder diffuses directly into cerebral blood vessels
what is an external hydrocephalus or communicating hydrocephalus?
decreased absorptive capacity of the arachnoid villi
what is internal hydrocephalus or noncommunicating
blockage of either foramen or somewhere else in the ventricular system
physiological importance of little mixing/crossing of blood in circle of willis
reduced blood flow in any one of the contributing vessels is not corrected by admixture from the other vessels po
post ganglionic symp fibers: innervation of Cereb vasc
cell bodies in superior cervical ganglia: NPY and norep
-alpha adrenergic receptors cause vasoconstriction
as intracranial presure increases, blood flow is ___ due to what
reduced due to compression of the BV
if there is an increase in intracranial pressure it ___ blood flow to the brain which triggers what
reduce
triggers the increase in systemic MAP even if the systemic BP is normal/high
