CSF is produced in the brain by modified ependymal cells in the choroid plexus (approx. 50-70%) and the remainder is formed around blood vessels and along ventricular walls. It circulates from the lateral ventricles to the foramen of Monro (Interventricular foramen), third ventricle, aqueduct of Sylvius (Cerebral aqueduct), fourth ventricle, foramen of Magendie (Median aperture) and foramina of Luschka (Lateral apertures), subarachnoid space over brain and spinal cord. It should be noted that the CSF moves in a pulsatile manner throughout the CSF system with nearly zero net flow. CSF is reabsorbed into venous sinus blood via arachnoid granulations.
It had been thought that CSF returns to the vascular system by entering the dural venous sinuses via the arachnoid granulations (or villi). However, some have suggested that CSF flow along the cranial nerves and spinal nerve roots allow it into the lymphatic channels; this flow may play a substantial role in CSF reabsorbtion, in particular in the neonate, in which arachnoid granulations are sparsely distributed. The flow of CSF to the nasal submucosal lymphatic channels through the cribriform plate seems to be especially important.
Read more about this topic: Cerebrospinal Fluid
Famous quotes containing the word circulation:
“The denunciation of the young is a necessary part of the hygiene of older people, and greatly assists the circulation of their blood.”
—Logan Pearsall Smith (18651946)
“We did not heed the sentries at the gate, nor did they us, and what under the sun they were placed there for, unless to hinder a free circulation of the air, was not apparent.”
—Henry David Thoreau (18171862)
“The circulation of confidence is better than the circulation of money.”
—James Madison (17511836)