The brain contains a series of ventricles that circulate cerebrospinal fluid (CSF) and serve important functions. There are four ventricles total - two lateral ventricles located within the cerebral hemispheres, the third ventricle within the diencephalon, and the fourth ventricle between the pons, medulla, and cerebellum. CSF is produced by the choroid plexus and circulates through the connected ventricles via openings like the foramen of Monro before being absorbed, acting as a cushion and transporting substances to and from the brain.

1. Ventricles of brain

2. The brain has a
series of ventricles
that hold CSF
(Cerebrospinal
Fluid).

3. • CSF is created by the
choroid plexus and
circulates through the
ventricles until it is
absorbed by the
arachnoid layer.

4. • CSF seems to
1. act as a fluid cushion for the brain
2. transports some substances into/out of the brain
3. maintains pressure around the brain.

5. BRAIN VENTRICLES
 The brain is bathed by the
cerebrospinal fluid (CSF)
 Inside the brain, there are
spaces (ventricles) filled
with CSF
 There are 4 ventricles
 2 lateral ventricles are
in the brain
hemispheres
 3rd ventricle is in the
diencephalon
 4th ventricle is
between the pons,
medulla and the
cerebellum

6.  They are connected by
 The foramen of monro
(lateral -> third),
 Cerebral aqueduct
( third -> fourth), and
 The foramen of magendie
and luschka
(fourth -> subarachnoid
space/cisterna magna).

8. Lateral Ventricle
 Definition :
 It is the cavity of
the cerebral
hemisphere.
 It is C-shaped.
 It has 3 horns &
central part.
 Anterior Horn: in
the frontal lobe.
 Posterior horn:
in the occipital
lobe
 Inferior horn: in
temporal lobe.
 Central part or
body: in the
parietal lobe.

9. Lateral Ventricle
 Superior view of the
ventricular system.
 Lateral ventricle
 Anterior horn in the frontal
lobe.
 Posterior horn in the
occipital lobe.
 Inferior horn in the temporal
lobe.
 Body: In the parietal lobe.
 The inferior and posterior
horns are connected in the
trigon.

11. Relationship of corpus callosum and
third ventricle

12. Suprolateral surface of brain

13. Relationship of caudate nucleusand
third ventricle

14. Anterior Horn
 In the frontal lobe.
 Roof:
 Corpus callosum
(trunk)
 Floor:
 Corpus callosum
(Rostrum)
 Caudate nucleus
head
 Anterior:
 Corpus callosum
(Genu)
 Medially:
 Septum pellucidum.

16. Body or Central part
 Lies in the parietal lobe.
 Roof:
 Corpus callosum (Trunk).
 Floor:
 Sloping, From lateral to
medial it is formed by:
 Body of caudate nucleus,
 Upper surface of
thalamus
 Choroid plexus,
 Body of fornix.
 Medial wall:
 Septum pellucidum.
 Lateral wall:
 narrow area at the
meeting of roof & floor.

17. Posterior Horn In the occipital lobe.
 Roof, lateral wall:
 Are formed by the
Tapetum of the corpus
callosum.
 Medially:
 There are 2 elevations:
Bulb of posterior horn
(formed by forceps
major-2-).
Calcar avis: produced by
calcarine sulcus-3-.

19. Inferior Horn
 It lies in the temporal lobe.
 Roof:
 Tapetum,
 Tail of caudate nucleus,
 Amygdaloid nucleus
 Stria terminalis.
 Floor:
 Hippocampus,
 Fimbria of hippocampus &
Collateral eminence.

20. Choroid Plexus of the Lateral Ventricle
 is a vascular fringe of pia mater
covered with the ependymal lining
of the ventricular cavity
 The choroid plexus projects into
the ventricle on its medial aspect

 At the junction of the body of the
lateral ventricle and the inferior
horn, the choroid plexus is
continued into the inferior horn.

22. Fourth ventricle

24. Fourth Ventricle
 A tent-shaped cavity filled
with cerebrospinal fluid.
 lined with ependyma
 continuous above with the
cerebral aqueduct of the
midbrain and below with the
central canal of the medulla
oblongata and the spinal cord


25. Situated
 anterior to the cerebellum
and
 posterior to the pons and
the superior half of the
medulla oblongata

26.  The fourth ventricle possesses
1. Lateral boundaries
2. Roof, and
3. Rhomboid-shaped floor.

27. Lateral Boundaries
 The caudal part .... the inferior cerebellar peduncle
 The cranial part ..... the superior cerebellar peduncle.

28. Roof or Posterior Wall
 The tent-shaped roof projects into
the cerebellum
 The superior part....medial
borders of the two superior
cerebellar peduncles and a
connecting sheet of white matter
called the superior medullary
velum
 The inferior part ..... the inferior
medullary velum, which consists of
a thin sheet devoid of nervous
tissue and formed by the
ventricular ependyma and its
posterior covering of pia mater

29. Fourth ventricle communicates with the subarachnoid
space through a single median and two lateral
apertures.
 In the midline ,the roof is
pierced by a large aperture, the
median aperture or foramen of
Magendie .
 Lateral recesses extend laterally
around the sides of the medulla
and open anteriorly as the
lateral openings of the fourth
ventricle, or the foramina of
Luschka .

30. Floor or Rhomboid Fossa
 The diamond-shaped floor
 formed by the posterior surface of the pons and the
cranial half of the medulla oblongata
 is divided into symmetrical halves by the median
sulcus.
 the medial eminence, ...
 the sulcus limitans.
 vestibular area ..vestibular nuclei

33. Nerve nuclei in floor of fourth ventricle

34. The facial colliculus
 the inferior end of the medial eminence
 produced by the fibers from the motor nucleus of the
facial nerve looping over the abducens nucleus
Substantia ferruginea
 Lies at the superior end of the sulcus limitans, there is a
bluish-gray area, nerve cells contain melanin pigment.
Stria medullaris
 Strands of nerve fibers derived from the arcuate nuclei,
emerge from the median sulcus and pass laterally over the
medial eminence and the vestibular area and enter the
inferior cerebellar peduncle to reach the cerebellum

35. Facial colliculus

36. Choroid Plexus of the Fourth Ventricle is formed
the posterior inferior cerebellar arteries.
 The choroid plexus has a T
shape
 The vertical part of the T
is double .
 Is formed from the highly
vascular tela choroidea.
 The tela choroidea is a
two-layered fold of pia
mater that projects
through the roof of the
ventricle and is covered by
ependyma.