Cerebrospinal fluid is a clear liquid
produced within spaces in the brain called ventricles. Like saliva it is a filtrate of blood. It is
also found inside the subarachnoid space of the meninges
which surrounds both the brain and the spinal chord. In
addition, a space inside the spinal chord called the central
canal also contains cerebrospinal fluid.
It acts as a
cushion for the neuraxis, also bringing nutrients to the
brain and spinal cord and removing waste from the
four spaces are filled with cerebrospinal fluid and protect
the brain by cushioning it and supporting its weight.
lateral ventricles extend across a large area of the
brain. The anterior horns of these structures are located in
the frontal lobes. They extend posteriorly into the parietal
lobes and their inferior horns are found in the temporal
ventricle lies between the two thalamic
bodies. The massa intermedia passes through it and the
hypothalamus forms its floor and part of its lateral walls.
ventricle is located between the cerebellum
and the pons.
ventricles are connected to one another.
Munro, which are also know as the
foramina, link the lateral ventricles to the
Sylvius which is also called the cerebral
aqueduct connects the third and fourth ventricles.
ventricle is connected to the subarachnoid space via two
lateral foramina of
Luschka and by one medial foramen of
Although cerebrospinal fluid is
manufactured in all of the ventricles, it circulates through
the system in a specific pattern, moving from the lateral
ventricle to the third, and then from the third to the
fourth. From the fourth ventricle, the cerebrospinal fluid
passes into the subarachnoid space where it circulates
around the outside of the brain and spinal cord and
eventually makes its way to the superior sagittal sinus via
the arachnoid granulations also called arachnoid villi. In the
superior sagittal sinus, the cerebrospinal fluid is
reabsorbed into the blood stream.
fluid of the neuraxis is regenerated several times every
Endolymph and perilymph, the fluids of the inner
ear, are derived from cerebrospinal fluid. Currently, there
is no consensus regarding the manner in which cerebrospinal
fluid enters the inner ear. Osmosis may be involved.
A condition called
hydrocephalus occurs when, for some
reason, too much cerebrospinal fluid is produced and the
ventricles swell, putting pressure on the tissue of the
brain. Tumors are one potential cause of an over-production
of cerebrospinal fluid.
should not be confused with hydroencephali. The term hydroencephali
literally means "water brain" and refers to a rare birth
defect in which the cerebrum is absent and the space where
it should be is entirely filled with cerebrospinal fluid.
In the past,
before CT and MRI technology existed, a technique involving
cerebrospinal fluid called pneumoencephalography was used to view the
brain. A small amount of cerebrospinal fluid was removed
from the ventricular system and replaced with air or some
other inert gas. This allowed the examiner to view the
ventricles in a scan and make inferences about brain
pathology. Tumors and hemorrhages could sometimes be located
by examining the shapes and sizes of the ventricles. Because
space within the cranium is limited, growths or coagulated
blood (hematoma) will displace white and gray matter,
pushing them into the ventricular system.
fluid can be analyzed to make judgments about a person's
general health as can blood and saliva .A sample is taken from the spinal cord via a
which is also known as a spinal tap.