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).
7.
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.
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.
15.
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-.
18.
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.
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
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
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.