Cerebrospinal fluid (CSF) II

Blood – CSF barrier     1) It’s formed by tight junctions between the choroidal epithelial cells 2) Permeable (From blood to CSF) for:...

Blood – CSF barrier
 
 
1) It’s formed by tight junctions between the choroidal epithelial cells
2) Permeable (From blood to CSF) for:

1. Water
2. Gas
3. Lipid soluble substance

3) Impermeable for macromolecules

1. Protein
2. Most of the hexoses (Other than glucose)

CSF physiology


1) Cerebral blood flow depends on the cerebral perfusion pressure (But in certain range of CPP, CBF is maintained constant by auto regulation mechanisms)

2) Cerebral perfusion pressure (CPP) = Mean arterial pressure (MAP) – Intracranial pressure (ICP)



Physiological fluctuations of ICP (Riding a rollercoaster)

Upward acceleration of the body	Downward acceleration of the body
Blood moves towards feet  : MAP at head level drops Venous pressure drops                         : ICP also drops Cerebral blood flow is less compromised	Blood moves towards head : MAP at the head level increases Venous pressure rises                           : ICP is increased Cerebral blood flow is less compromised  Cerebral blood vessels are supported & prevented from rupture Same mechanism is seen during defecation & child delivery

Pathological changes of ICP






Changes occur when the ICP rises & treatment