Hi rls11,
The following is the result of my research of the volume of cerebrospinal fluid:
Spinal Fluid:
"The cerebrospinal fluid (CSF):
a) provides cushioning for the delicate neural structures and support
for the brain since it literally floats in this fluid. Alone, the
brain weighs about 1400 grams (3.1 lb.), but it only weighs 50 g (1.76
oz.) when supported by the cerebrospinal fluid.
b) transports nutrients, chemical messengers, and waste products.
c) is in constant chemical communication with the interstitial fluid
of the CNS through the permeable ependymal lining except at the
choroid plexus.
d) is produced at the choroid plexus, a vascular network that extends
into each of the four ventricles. It then circulates between the
different ventricles, passes along the central canal, and enters the
subarachnoid space. Once inside, it continues around the spinal cord
and cauda equina and across the surfaces of the brain.
e) is secreted at a rate of about 500 ml/day, and the volume at any
given moment is approximately 150 ml, with the entire volume being
replaced every eight hours."
Innvista: Spinal Fluid
http://www.innvista.com/health/anatomy/spinalfl.htm
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Cerebrospinal Fluid
"The ventricles of the brain, the central canal of the spinal cord and
the subarachnoid spaces contain cerebrospinal fluid (CSF), which acts
as a liquid buffer to absorb and distribute external or internal
forces endangering the brain and cord. In the adult, there is
continuous formation, circulation and absorption of about 125 to 150
ml of fluid. It has been calculated that 430 to 450 ml of CSF are
produced every day, so the fluid must be changed every 6 to 7 hours.
The choroid plexuses of the lateral ventricles are the largest and
produce most of the CSF. The fluid flows through the interventricular
foramina (of Monro) into the third ventricle, is augmented by fluid
formed by the choroid plexus of this ventricle, and passes through the
cerebral (sylvian) aqueduct to the fourth ventricle, which also
possesses a choroid plexus. The CSF from all these sources escapes
from the fourth ventricle into the subaracchnoid space. Most of the
CSF is directed upward over the cerebral hemispheres toward the
superior sagittal sinus. The CSF is reabsorbed into the blood through
the arachnoid villi."
Benksea: Neurosurgery
http://www.geocities.jp/benksea/e-yougo_btm.html
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Physiology of Cerebrospinal Fluid
"Cerebrospinal fluid (CSF) flows within the ventricles of the brain,
the central canal of the spinal cord and out to the subarachnoid
spaces surrounding the brain and spinal cord, effectively floating
these two structures. It serves as a medium for the transfer of
substances between the blood and the nervous tissues as well as a
liquid buffer, absorbing mechanical
shocks to the brain or the cord. Most of CSF is provided by the
choroid plexuses that reside in lateral, third and fourth ventricles.
In adults, the volume of this fluid has been calculated to be from 125
to 150 ml (4-5 oz). It is in continuous formation, circulation and
absorption.
Approximately 430 to 450 ml (nearly 2 cups) of CSF are produced every
day, or 0.35 ml per minute in adults and 0.15 per minute in infants."
Hyman-Newman Institute for Neurology and Neurosurgery: Neuroanatomy & Physiology
http://nyneurosurgery.org/neuroanatomy.htm
===================================
Cerebrospinal Fluid - Formation and Composition
"The CSF is a clear colourless fluid with a specific gravity (1.004 -
1.007 g/cm 3) slightly greater than water. It normally contains little
protein and has a lower pH, and lower concentration of glucose,
potassium, calcium, bicarbonate and amino acids than blood plasma. The
sodium, chloride, and magnesium content, however, is greater in CSF
than in blood plasma. Few cells are usually present in the CSF; 0-8
cells/ mm 3 in infants and 0-5 cells/mm 3 in adults is considered
normal. Changes in the composition (increased protein)
or in the appearance (cloudiness) of the CSF would suggest some
neurologic disease.
In man, the total volume of CSF contained within the ventricular
system and the subarachnoid space is estimated to be 80-150 ml and The
ventricular system alone is believed to contain from 15-40 ml of CSF
and 75 ml surrounds the spinal cord."
University of Manitoba: Cerebral Ventricular System and Cerebrospinal Fluid
http://www.umanitoba.ca/faculties/medicine/anatomy/csf-form.htm
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"Cerebrospinal-fluid volume, which is about 123 ml total in adults, is
divided 25 ml in the ventricles and 98 ml in the subarachnoid spaces
that bathe the brain and spinal cord. There is a great degree of
variability between individuals. Cerebrospinal-fluid volume needs to
be in constant homeostasis between production and reabsorption."
The International Alliance of Healthcare Educators
The Circulation Between Cerebrospinal Fluid, Cerebral Interstitial Fluid and Lymph
http://www.iahe.com/controller/ArticleDisplay?id=10344
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CSF formation and circulation
"The rate of CSF formation is 0.35?0.4 ml/min or 500?600ml/day. The
turnover time of total CSF volume is four to five hours. Total CSF
volume is 140 ml. CSF is formed in the choroid plexus in the two
lateral ventricles and then passes through the paired interventricular
foramina of Monro into the third ventricle. CSF then flows caudally
through the aquaduct of Sylvius and fourth ventricle and into the
subarachnoid space by one of three exits. Two are the lateral foramina
of Luschka and the third is the midline foramen of Magendie, from
which CSF flows into the subarachnoid space around the brain and
spinal cord. A small portion of CSF may also leave the fourth
ventricle through the central canal of the spinal cord."
Reabsorption of CSF
"85?90% of CSF is absorbed at intracranial sites through arachnoid
villi and granulations bordering the superior sagittal sinus and
venous lacunae. 10?15% of CSF is reabsorbed at spinal sites."
The Royal College of Anaesthetists: Neuroanatomy and neurophysiology
http://www.rcoa.ac.uk/docs/b22_primary.pdf
===================================
From the fourth ventricle the CSF flows into :
*central canal of spinal cord (20%)
*subarachnoid space (80%) via lateral aperture of fourth ventricle
http://focosi.altervista.org/nervoussystem.html#ventricles%20of%20the%20brain
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"80-150 ml of CEREBROSPINAL FLUID (CSF) circulates through spaces in
and around the brain and spinal cord. CSF circulates through the
SUBARACHNOID SPACE in the brain and spinal cord, the CENTRAL CANAL of
the spinal cord, and the VENTRICLES of the brain. The VENTRICLES are
cavities in the brain that are interconnected with each other and with
the subarachnoid space and central canal.
The composition of the cerebrospinal fluid (CSF) is much like blood
plasma; it is a clear, colorless fluid that contains glucose,
proteins, lactic acid, urea, salts, and some white blood cells.
Clusters of capillaries in the walls of the VENTRICLES, called the
CHOROID PLEXUSES, filter blood to continuously form about 800 ml of
CSF daily. Once it is formed, CSF circulates through the VENTRICLES of
the brain, the SUBARACHNOID SPACES of the brain & spinal cord, and the
CENTRAL CANAL of the spinal cord. The CSF eventually makes its way to
the anterior portion of the brain, where most of it is reabsorbed into
INTRACRANIAL VASCULAR SINUSES. The cerebrospinal fluid picks up
metabolic wastes as it circulates past the nervous tissue of the brain
and spinal cord. These metabolic wastes then move into the bloodstream
in the intracranial vascular sinuses as the CSF is absorbed. The blood
carries these wastes away to be eliminated from the body by the lungs
and kidneys."
Morehead State University: BIOL 231 Human Anatomy
http://people.morehead-st.edu/fs/m.mcmurr/231-L25.html
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CEREBROSPINAL FLUID VOLUME & DISTRIBUTION
"The cerebrospinal fluid fills the cavity of the ventricles and the
subarachnoid spaces. The subarachnoid spaces are wide in certain areas
and these are called cisterns. At the cerebellomedullary area the
cistern is called cisterna magna. We have also the pre-pontine cistern
surrounding the basilar artery and the interpeduncular cistern
surrounding the circle of Willis. The subarachnoid space extends
caudally around the spinal cord and ends in lumbar -sacral dural sac
where it surrounds the cauda equina.
The average volume of intracranial cerebrospinal fluid is 125 mls with
89 mls in the subarachnoid space The volume of CSF in the lumbar sac
is about 30 mls."
The University of Adelaide: HYDROCEPHALUS
http://www.health.adelaide.edu.au/paed-neuro/hydro.html
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More can be read here:
Department of Physiology - University of Wisconsin
Examination of Gross Human Brain
http://www.physiology.wisc.edu/phys675lab/physiol_675_lab_i.htm
Search criteria:
fluid "central canal" "spinal cord"
"cerebrospinal fluid" "central canal" "10..150 ml"
"cerebrospinal fluid" "central canal" "10..150 ml" volume
I hope the information provided is helpful. If you have any questions
regarding my answer please don?t hesitate to ask before rating it.
Best regards,
Rainbow |
