The Ventricular Anatomy

1. THE VENTRICULAR
SYSTEM
BY WAJIHA NASEER

2. INTRODUCTION
 The ventricles are cavities that
produce cerebrospinal fluid,
and transport it around the
cranial cavity.
 They are lined by ependymal
cells and are embryologically
derived from cavity of neural
tube.
 In total, there are four ventricles:
-Right and left lateral ventricles
in cerebral hemispheres
-Third ventricle in diencephalon
-Fourth ventricle between the
pons, medulla and cerebellum

3.  Lateral ventricles
communicate with third
ventricle through
interventricular foramina(of
Monro).
 Third ventricle is connected to
fourth ventricle by narrow
cerebral aqueduct.
 Fourth ventricle is continuous
with central canal of spinal
cord and subarachnoid space
through three foramina in its
roof.
 Central canal in spinal cord
has a small dilatation at its
inferior end called Terminal
ventricle.

5. LATERAL VENTRICLES

6.  It is a cavity of cerebral
hemisphere
 It is C-shaped
 It has three horns and
central part (body)
 Anterior horn in Frontal
lobe
 Posterior horn in
Occipital lobe
 Inferior horn in
Temporal lobe
 Central part or body in
Parietal lobe

7. Superior View:

8. Anterior Horn
 Roof:
Corpus Callosum (Trunk)
 Floor:
Corpus Callosum
(Rostrum)
Head of caudate nucleus
 Anteriorly:
Corpus Callosum (Genu)
 Medially:
Septum pellucidum

10. Body or Central Part
 Roof:
Corpus Callosum (Trunk)
 Floor:
Body of Caudate nucleus
Upper surface of Thalamus
Body of fornix
Choroid plexus
 Medially:
Anteriory Septum
pellucidum
Posteriorly roof anf floor
come together at the medial
wall

11. Posterior Horn
 Roof and Lateral wall
Fibres of the Tapetum of the
Corpus Callosum
 Medial wall:
It has two swellings
-Superior swelling is caused
by splenial fibres of Corpus
Callosum
It is called Bulb Of
Posterior Horn.
-Inferior swelling is
produced by calcarine
sulcus
It is called Calcar Alvis.

12. Inferior Horn
 Roof:
Inferior surface of tapetum of
corpus callosum
Tail of caudate nucleus
(which ends in amygdaloid
nucleus)
Stria Terminalis
 Floor:
Laterally by Collateral
eminence
Medially by Hippocampus

13. THIRD VENTRICLE
 It is a slit like cleft between
two thalami
 It communicates anteriorly
with the lateral ventricles
through foramen of Monro
 It communicates posteriorly
with fourth ventricle through
cerebral aqueduct

14. Boundaries
 Anterior Wall:
Lamina terminalis (anterior coMmissure runs across it)
 Posterior Wall:
Opening into cerebral Aqueduct
Superior to opening is posterior commissure
 Lateral wall:
Superiorly by medial surface of thalamus
Inferiorly by hypothalamus
 Superior wall or Roof:
Two-layered fold of pia mater called the Tela choroidea of the third
ventricle
 Inferior wall or Floor:
Optic chiasma, The tuber cinereum, infundibulum, mammillary
bodies

16. FOURTH VENTRICLE
 A Tent shaped
cavity filled with
CSF
 Situated Anterior to
cerebellum and
posterior to pons
and superior half of
medulla

17. Lateral Boundaries
 Caudal part of each
lateral boundary is
formed by the
Inferior cerebeller
peduncle
 The Cranial part is
formed by Superior
cerebller peduncle

18. Roof or Posterior Wall
 Tent shaped rood projects into
cerebellum
 Superior part is formed by medial
borders of the superipr cerebeller
peduncles and connecting white
matter called superior medullary
velum
 The inferior part of the roof is
formed by Inferior medullary velum,
which is formed by ventricular
edendyma and posterior covering of
pia mater
 The rood is pierced in the midline by
a aperture, the foramina of
Magendie
 Lateral recesses extend laterally
around the medulla and open
anteriorly as foramina of Luschka

19. Floor or Rhomboid fossa
 The diamond shaped floor is formed by posterior surface of
the pons and the cranial half of medulla oblongata
 The floor is divided into symmetrical halves by median
sulcus.
 On each side of sulci (from medial to lateral):
Medial eminence
Sulcus Limitans
Vestibular Area

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