CSF Secretion and the BBB

Question 0

Acetazolamide

Answer 0

Carbonic anhydrase inhibitor

Decreases epithelial levels of HCO3- necessary for Na+ co-transport into the ventricles

Question 1

Oubain

Answer 1

Inhibits Na+/K+-ATPase

-Would stop channels at the apical surface of choroid epithelial cells

Question 2

Vasogenic edema

Answer 2

Leakage of plasma proteins into the CNS due to disruption of the BBB

-increases osmotic pressure of ISF drawing in water

Question 3

Interstitial edema

Answer 3

Fluid imbalance b/w the CSF filling the ventricles and the surrounding brain

• In obstructive hydrocephalus, passages b/w ventricles are blocked and CSF will flow into the ISF causing edema
• Can flow here because no tight jnxns formed b/w pia and ependymal cells

Question 4

Cytotoxic Edema

Answer 4

Depletion of ATP causing unregulated movement of ions

Question 5

Osmotic edema

Answer 5

Decreased plasma osmolarity caused water to accumulate in the CMS

Question 6

Hydrostatic edema

Answer 6

Hydrostatic pressure forces fluid across the BBB usually due to malignant hypertension