Csf production,circulation & absorption

Tuesday, April 11, 2023 1

CSF PRODUCTION, CIRCULATION &ABSORPTION

LECTUREBY

DR. ANSARICHAIRPERSON & PROF. OF ANATOMYRAK COLLEGE OF MEDICAL SCIENCES

& RAK COLLEGE OF DENTAL SCIENCES


A 9 year old boy was brought to his GP by his parents who noted that he was having difficulty with his balance and was complaining of head aches.

• He was referred to the neurosurgical unit and a CT scan was perform of his head region. This showed the presence of dilated lateral and III ventricles with a normal IV ventricle. There was effacement of the overlying cortical sulci in the brain and a diagnosis of Hydrocephalus was made. MRI showed the cerebral aqueduct was stenosed.

• The boy subsequently had a III ventriculostomy performed, and his symptoms resolved rapidly.



C.S.F Circulation involves

• Lateral ventricle.• III ventricle.• Cerebral aqueduct.• IVventricle.• Subarachnoid cisterns• Subarachnoid spaces


Sub arachnoid cisterns & spaces• The major cisterns are:-• 1) Cisterna interpeduncularis• 2) Cisterna ambiens• 3) Cisterna magna 4) Cistern of the lateral sulcus• 5) Cisterna pontis• 6) Subarachnoid spaces




The arachnoid villi & granulations

• Are the structures that drain the excess amount of CSF into the circulatory system/Dural venous sinuses.

• These are the safety valve that opens up and drain into the superior Sagittal sinus.

• From the ventricles the CSF comes out into the subarachnoid sinuses through 3 apertures,

• Foramen of Magendie & foramina of Lusaka


The CSF is drained in to the superior sagittal sinus through the arachnoid villi and granulations


Humans produce 500 ml of CSF daily The total CSF volume is only 1/3 of the daily

production.• Most of the 500 ml of CSF is produced in the choroid

plexuses in the four brain ventricles, and the remaining is produced across the blood-brain barrier.

• The CSF passes from the lateral ventricles (I and II) through the foramen of Monroe into the third ventricle (III), through the aqueduct of Sylvius, the fourth ventricle (IV), and out into the subarachnoid space through the foramina Lushka & Magendie .


(18) foramina of Lushka


Foramen of Monro/interventricular foramen (12)


Cast of the ventricles of brain

1. Anterior horn of lateral ventricle

2. Body of lateral ventricle 3. Posterior horn of lateral

ventricle 4. Inferior horn of lateral

ventricle 5. Third ventricle 6. Fourth ventricle 7. Interventricular foramen 8. Cerebral aqueduct


The lateral ventricles

• Situated in the cerebral hemispheres, it has a body, an anterior horn in the frontal pole, posterior horn in the occipital pole &inferior horn in the temporal pole.

• The two lateral ventricles are interconnected by interventricular foramen and it also communicates with the III ventricle.

• All ventricles are lined by ependyma.• The choroid plexus are formed by a dual layer of

ependyma invaded by bunch of capillaries.



Tela choroidea (7) is a double fold of Pia mater entering into the choroid fissure and forming the organs for CSF formation

along with the choroid plexus


Tela choroidea


The duct of Sylvius/Cerebral aqueduct forms the cavity of midbrain



Roof of IV ventricle formed by cerebellum and superior cerebellar peduncles and superior medullary velum


The fifth ventricle & terminal ventricle• The central canal expanding at the level of filum

terminale, of conus medullaris, is the terminal ventricle.

• The fifth ventricle is the median cleft between the two laminae of the brain's septum pellucidum (cavum septum pellucidum).

• The CSF is getting emptied / drained into the dural venous sinuses through the arachnoid villi and granulations.


Cavum Septum pellucidum


A sagittal section of the brain showing the ventricles



III Ventricle

• It lies below the lateral ventricles.• It is a cavity of the diencephalon. In the roof there is

choroid plexus, that produce CSF. • Superiorly it communicates with the two lateral

ventricles through the interventricular foramen.• Inferiorly it communicates with the IV ventricle

through the cerebral aqueduct.• The lateral wall is formed by thalamus and

hypothalamus. The two thalami are annexed by interthalamic adhesion.


Structures in the lateral wall of III ventricle

1. Thalamus 2. Hypothalamus 3. Midbrain 4. Pons 5. Interthalamic adhesion 6. Anterior commissure 7. Optic chiasma 8. Mammillary body 9. Pineal body 10. Tectum of midbrain 11. Lamina terminalis 12. Interventricular foramen


IV Ventricle

• It is a cavity of the rhombencephalon.

• It has a roof and floor.• The floor is formed by two

parts, medullary & pontine part.

• Hypoglossal nucleus, vagal nucleus, trigeminal nucleus, glossopharyngeal nucleus, auditory nuclei and facial and abducent nuclei are located in the floor.


Applied anatomy of ventricles of brain

• Hydrocephalus• Anencephaly• Spina bifida• Meningitis• Encephalitis


Imaging study showing enlarged cavities of brain due to hydocephalous

Date post:	07-May-2015
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Csf production,circulation & absorption

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