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ANATOMY OF THE CEREBRAL VENTRICLES
Francois du Toit
Diagnostic Radiology
Kimberley Hospital
The Cerebral Ventricles
Fluid filled (CSF) spaces within the brain
2 Lateral ventricles in each hemisphere
3rd ventricle, Cerebral Aquaduct, 4th ventricle midline
Ependyma (thin epithelial membrane lining)
The Cerebral Ventricles
THE LATERAL VENTRICLE
The Lateral Ventricles
• Lies within each cerebral hemisphere:• Frontal Horn (anterior)• Body (atrium)• Temporal Horn (inferior)• Occipital Horn (posterior)
• Interventricular Foramen (of Monroe)• connects each lateral ventricle with the 3rd ventricle• at junction of anterior horn & body
The Lateral Ventricles
The Lateral Ventricles
FRONTAL HORN
THE LATERAL VENTRICLE
Frontal (anterior) Horn
Extends into frontal lobe
Roof & Ant extremity formed by: Corpus Collosum (Rostrum & Genu) Tapetum
Floor & Lateral Wall Caudate Nucleus
Medial Wall Septum Pellucidum
Roof / Anterior Border
Roof / Anterior Border
Frontal (anterior) Horn
Extends into frontal lobe
Roof & Ant extremity formed by: Corpus Collosum (Rostrum & Genu) Tapetum
Floor & Lateral Wall Caudate Nucleus
Medial Wall Septum Pellucidum
Floor of Anterior Horn
Floor of Anterior Horn
Frontal (anterior) Horn
Extends into frontal lobe
Roof & Ant extremity formed by: Corpus Collosum (Rostrum & Genu) Tapetum
Floor & Lateral Wall Caudate Nucleus
Medial Wall Septum Pellucidum
Medial Wall of Anterior Horn
BODY (atrium)
THE LATERAL VENTRICLE
Body of Lateral Ventricle
In Parietal Lobe Roof & Lateral Wall
Corpus Callosum Tapetal Fibres
Medial wall Septum Pellucidum
Floor (medial) Thalamus
Floor (lateral) Body of Caudate Nucleus
Thalamostriate vein in between Body of Fornix lies above the thalamus Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure
Roof / Anterior Border
Body of Lateral Ventricle
In Parietal Lobe Roof & Lat
Corpus Callosum Tapetal Fibres
Medial wall Septum Pellucidum
Floor (medial) Thalamus
Floor (lateral) Body of Caudate Nucleus
Thalamostriate vein in between Body of Fornix lies above the thalamus Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure
Body of Lateral Ventricle
In Parietal Lobe Roof & Lat
Corpus Callosum Tapetal Fibres
Medial wall Septum Pellucidum
Floor (medial) Thalamus
Floor (lateral) Body of Caudate Nucleus
Thalamostriate vein in between Body of Fornix lies above the thalamus Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure
Body of Lateral Ventricle
Caudate Nucleus
Thalamus
The Lateral Ventricles
Body of Lateral Ventricle
In Parietal Lobe Roof & Lat
Corpus Callosum Tapetal Fibres
Medial wall Septum Pellucidum
Floor (medial) Thalamus
Floor (lateral) Body of Caudate Nucleus
Thalamostriate vein in between Body of Fornix lies above the thalamus Between the fornix and the thalamus
Choroid plexus lies invaginated into the cavity of the ventricle in a groove - the choroidal fissure
Thalamus
Body of Fornix
Choroid Plexus
The Lateral Ventricles
TEMPORAL HORN (inferior)
THE LATERAL VENTRICLE
Temporal (inferior) Horn
Extends anteriorly into Temporal Lobe Lateral wall
Fibres of Tapetum
Roof Tail of Caudate Nucleus
Floor Hippocampus pes hippocampi anterior crus of the fornix arising from this
Temporal Horn of Lateral Ventricle
Tapetum
Temporal (inferior) Horn
Extends anteriorly into Temporal Lobe Lateral wall
Fibres of Tapetum
Roof Tail of Caudate Nucleus
Floor Hippocampus pes hippocampi anterior crus of the fornix arising from this
Temporal (inferior) Horn
Extends anteriorly into Temporal Lobe Lateral wall
Fibres of Tapetum
Roof Tail of Caudate Nucleus
Floor Hippocampus pes hippocampi anterior crus of the fornix arising from this
Crus of Fornix
Hippocampus
Pes
OCCIPITAL HORN (Posterior)
THE LATERAL VENTRICLE
Occipital (posterior) Horn
Posterior Extension of Lateral ventricle Extends into Occipital Lobe Arises from trigone of lateral ventricle
posterior convexity of the body of the lateral ventricle
May be absent / poorly developed / extend the full depth 12% bilaterally well developed
THE CHOROID PLEXUS
Choroid Plexus of Lateral Ventricle
Responsible for most of the production of CSF Extends from Inferior horn, through body, to interventricular
foramen NO CHOROID PLEXUS in Occipital & Frontal Horn Continuous with Choroid Plexus of 3rd ventricle Invaginated into Lateral Ventricles medially
(Choroidal Fissure)
Choroid Plexus of Lateral Ventricle
Choroid Plexus of Lateral Ventricle
Blood supply: Ant Choroidal a. (Branch of ICA) Post Choroidal a. (Branch of post Cerebral a.)
Venous drainage: Sup Choroidal vein (begins at inferior horn and
passes anteriorly to IV foramen) Joins Sup Thalamostriate v. to form Internal Cerebral
vein at IV foramen
3rd Ventricle
Slit-like space between Thalami Width = 2-10mm (increasing with age) Thin anterior wall – Lamina Terminalis
between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea Narrow Anterior Apex at IV Foramen Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum
Third Ventricle
Thalamus
3rd Ventricle
Slit-like space between Thalami Width = 2-10mm (increasing with age) Thin anterior wall – Lamina Terminalis
between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea Narrow Anterior Apex at IV Foramen Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum
Lamina Terminalis
Optic Chiasm
Anterior Commisure
3rd Ventricle
Slit-like space between Thalami Width = 2-10mm (increasing with age) Thin anterior wall – Lamina Terminalis
between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea Narrow Anterior Apex at IV Foramen Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum
3rd Ventricle
Slit-like space between Thalami Width = 2-10mm (increasing with age) Thin anterior wall – Lamina Terminalis
between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea Narrow Anterior Apex at IV Foramen Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum
3rd Ventricle
Slit-like space between Thalami Width = 2-10mm (increasing with age) Thin anterior wall – Lamina Terminalis
between ant commissure (above) to optic chiasm (below)
Extension inferiorly into optic chiasm = supraoptic recess
Floor = Structures of hypothalamus including pituitary whose hollow stalk is the infundibular recess of the ventricle
Fold of Pia containing CP = Tela Choroidea Narrow Anterior Apex at IV Foramen Wider Posterior
If Fluid accumulates = Cavum Velum Interpositum
Cavum Velum Interpositum
3rd Ventricle
Posteriorly - extends as small pineal recess into pineal stalk, and above this into suprapineal recess
Roof - anteriorly, the anterior commissure, column of fornix and IV foramen.Behind this the body of the fornix, with Choroid plexus invaginating below the fornix
60% of people - thalami connected across the ventricle via massa intermedia (non-neural connection)
3rd Ventricle
Posteriorly - extends as small pineal recess into pineal stalk, and above this into suprapineal recess
Roof - anteriorly, the anterior commissure, column of fornix and IV foramen.Behind this the body of the fornix, with Choroid plexus invaginating below the fornix
60% of people - thalami connected across the ventricle via massa intermedia (non-neural connection)
Fornix
Ant Commisure
Choroid Plexus
3rd Ventricle
Posteriorly - extends as small pineal recess into pineal stalk, and above this into suprapineal recess
Roof - anteriorly, the anterior commissure, column of fornix and IV foramen.Behind this the body of the fornix, with Choroid plexus invaginating below the fornix
60% of people - thalami connected across the ventricle via massa intermedia (non-neural connection)
THE CEREBRAL AQUEDUCT
Cerebral Aquaduct
Narrow channel connecting post end of 3rd ventricle with sup end of 4th ventricle
1.5cm in length. 1-2mm in diameter
Passes through Brainstem with Tectum posterior to it and Tegmentum and Cerebral Peduncles anteriorly
Nuclei of CN III,IV,V surround aqueduct and are called the periaqueductal grey matter
Cerebral Aqueduct
4th Ventricle
Aqueduct widens Posterior to the Pons Narrows again in inferior part of medulla as
central canal of the medulla & of spinal cord Floor = diamond shaped (rhomboid fossa)
Formed by post surface of pons and upper part of medulla Roof
SUPERIORsuperior cerebellar peduncle with sup medullary velum betweenINFERIORinf cerebellar peduncle and the inf medullary velum
Over these lies the cerebellum
4th Ventricle
4th Ventricle
4th Ventricle
Aqueduct widens Posterior to the Pons Narrows again in inferior part of medulla as
central canal of the medulla & of spinal cord Floor = diamond shaped (rhomboid fossa)
Formed by post surface of pons and upper part of medulla Roof
SUPERIORsuperior cerebellar peduncle with sup medullary velum betweenINFERIORinf cerebellar peduncle and the inf medullary velum
Over these lies the cerebellum
4th Ventricle Roof
Foramina
4th Ventricle
Foramina of 4th Ventricle
3 Openings in lower part of roof one median aperture (of Magendie)
large opening in inf medullary velum beneath the cerebellum, which communicates with the cisterna magna
two lateral apertures (of Luschka) at apex of lateral recesses of the ventricle open anteriorly just behind CN VIII into the pontine
cistern Choroid plexus invaginates the lower part of its roof and is
supplied by inferior cerebellar a.
Foramen of Magendie
4th Ventricle Foramina
3 Openings in lower part of roof one median aperture (of Magendie)
large opening in inf medullary velum beneath the cerebellum, which communicates with the cisterna magna
two lateral apertures (of Luschka) at apex of lateral recesses of the ventricle open anteriorly just behind CN VIII into the pontine
cistern Choroid plexus invaginates the lower part of its roof and is
supplied by inferior cerebellar a.
Foramen of Luschka
4th Ventricle Foramina
3 Openings in lower part of roof one median aperture (of Magendie)
large opening in inf medullary velum beneath the cerebellum, which communicates with the cisterna magna
two lateral apertures (of Luschka) at apex of lateral recesses of the ventricle open anteriorly just behind CN VIII into the pontine
cistern Choroid plexus invaginates the lower part of its roof and is
supplied by inferior cerebellar a.
Choroid Plexus of 4th Ventricle
CSF PRODUCTION & FLOW
CSF Production & Flow
Total Volume of CSF = 150ml (25ml is within and around the spinal cord)
Produced at 0.4ml/min
Production independent of CSF pressure
Principally produced by Choroid Plexus of lateral ventricles
CSF Flow
Flows through Interventricular foramen into 3rd ventricle Via Cerebral Aqueduct to 4th Ventricle Via Midline Aperture (of Magendie) into Cisterna Magna Via Lateral Apertures into Pontine Cistern From Basal Cisterns
some fluid flows down and bathes the spinal cord
The Remainder passes upward through tentorial hiatus and diffuses over surface of
the cerebral hemispheres
CSF Flow
Into 3rd Ventricle (Monroe)
Into 4th Venticle (Cerebral Aqueduct)
Into Cisterna Magna (Magendie)
Down to Spinal Cord
Upwards over Cerebral Hemispheres
CSF Absorbtion
CSF is absorbed through the Arachnoid Villi herniations of arachnoid through holes in the dura into
venous sinuses most numerous in sup sagittal sinus discrete in children with age they aggregate into visible clumps called
arachnoid granulations these indent the inner table of the skull beside the dural
venous sinuses
Arachnoid Villi
CSF Absorbtion
1/3 CSF absorbed along similar spinal villi OR
escapes along nerve sheaths into perineural lymphatics
This absorption is passive and dependent on hydrostatic pressure differences
ANATOMICAL VARIANTS
Cavum Velum Interpositum
Fluid Collects in Tela Choroidea Narrow apex anterior Wider Posteriorly
Cavum Velum Interpositum
Cavum Septum Pellucidum
Two potential spaces between leaflets of Septum Pellucidum ANTERIOR Cavum Septum Pellucidum POSTERIOR Cavum Vergae
Obliterate Postero-anteriorly during development CSP present in 100% of fetusses 85% Obliterate by 3-6months Absent CSP in fetus associated with significant CNS
abnormalities
Cavum Vergae
Seperation of the leaflets of septum pellucidum Posterior extension to the splenium of corpus
collosum Because of ordered obliteration – CSP almost always
accompanies a Cavum Vergae
Cavum Vergae
Cavum Septum Pellucid
umCavum Vergae
References
Anatomy for Diagnostic Imaging, 3rd EditionStephanie Ryan, Michelle McNicholas, Stephen Eustace
Atlas of Human Anatomy, 2nd EditionFrank H. Netter
http://www.imaios.com/
http://www.radiopaedia.org/
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