2. MENINGES
The interior of the cranial cavity is
lined by the durameter.
The surface of the brain is covered
by the piameter.
The dura is separated from the
arachnoid by subdural space.
The arachnoid is separated from
the pia by subarachnoid space.
(CSF)
Between these two lies the
arachnoid mater.
These three together constitute
the meninges of the brain.
3. DURAMATER
The cerebral duramater
consisting of the outermost
thickest and toughest membrane
consisting of two layers.
Outer endosteal layer
(endocranium) periosteum lining
the inner surfaces of the skull
bones.
Inner meningeal layer (duramater
proper) encloses the brain and at
the foramen magnum becomes
continuous with the duramater
surrounding the spinal cord.
4. DURAL FOLDS
At places, the meningeal
layer is folded on itself to
form dural folds(dural
septa).
Falx cerebri
Tentorium cerebelli
Falx cerebelli
Diaphragma sella
5.
6.
7. Falx cerebri Tentorium cerebelli Falx cerebelli Diaphragma
sella
Shape
&
location
Large sickle shaped
Median longitudinal
fissure
Tent shaped
Cerebellum &
occipital lobes
Sickle shaped
Posterior
cerebellar notch
Small circular
Roof of the
hypophyseal
fossa
Attach
ments
Crista galli
Median plane of
upper surface of
tentorium cerebelli
Transverse sulcus
Petrous temporal
bone, post. Clinoid
process
Inf surface of
tentorium
cerebelli on
median plane
Tuberculum
sellae, dorsum
sellae
Dura middle
cranial fossa
Margins Upper-Convex
saggital sulcus
Lower-Concave free
U-shaped ant free
margin ant clinoid
process. bears
tentorial notch
Apex -foramen
magnum
convex-internal
occipital crest
--------
Surface Medial surface of
cerebral
hemisphere
Superiorly –occipital
lobe of cerebrum
inferiorly-superior
cerebellum
------- hypophysis
cerebri
Sinus Superior & inferior Transverse Occippital ---------
8.
9.
10.
11.
12. TRIGEMINAL OR MECKEL’S CAVE
It is a recess of the dura
mater present in relation to
the attached outer margin of
the tentorium cerebelli
It is formed by the
evagination of the meningeal
layer of duramater by two
roots of the trigeminal nerve
below the superior petrosal
sinus over the trigeminal
impression on the anterior
surface of the petrous
temporal bone near its apex
13. BLOOD SUPPLY OF DURA
The vault- supplied by middle meningeal artery
The anterior cranial fossa and the dural lining- supplied by anterior
ethmoidal, posterior ethmoidal and ophthalmic arteries
The middle cranial fossa- supplied by middle meningeal arteries, accessory
meningeal and internal carotid arteries, and meningeal branches of ascending
pharyngeal artery.
The posterior cranial fossa- supplied by meningeal branches of vertebral,
occipital and ascending pharyngeal arteries
14.
15. NERVE SUPPLY OF DURA
The dura of the vault is supplied by sensory nerves derived
from ophthalmic division of trigeminal nerve
The dura of the floor has rich nerve supply and is sensitive
to pain:
- anterior cranial fossa- supplied by anterior ethmoidal
nerve and partly by maxillary nerve
- middle cranial fossa- supplied by maxillary nerve in the
anterior part and by branches of mandibular nerve and from
the trigeminal ganglion in the posterior part
- posterior cranial fossa- supplied by recurrent branches of
1st, 2nd and 3rd cervical spinal nerves and by meningeal
branches of 9th and 10th cranial nerves
16.
17. CLINICAL ANATOMY
EXTRA DURAL AND SUBDURAL HAEMORRHAGES
Common
Distinguished by
Extradural Haemorrhage is arterial (injury to middle
meningeal artery) Subdural Haemorrhage- venous
Extradural Haemorrhage - symptoms of cerebral
compression are late
Extradural Haemorrhage- paralysis appears first in the
face and then spreads to lower parts of the body. Subdural
Haemorrhage - haphazard
Extradural Haemorrhage- no blood in the CSF. - Subdural
Haemorrhage- it is a common feature.
18.
19. CAVERNOUS SINUS
Large venous space
Situation- Middle cranial fossa on either
side of body of sphenoid bone
Divided into caverns (spaces) by
trabeculae (prominent in dead)
Floor & medial wall – endosteal duramater
Lateral wall & roof – meningeal duramater
EXTENSION
Anteriorly- superior orbital fissure
Posteriorly- apex of petrous temporal bone
2cm long, 1cm wide
20. RELATIONS
SUPERIORLY
Optic chiasma
Optic tract
Olfactory tract
Internal carotid artery
INFERIORLY
Foramen lacerum
Junction of the body and the greater
wing of sphenoid
MEDIALLY
Hypophysis cerebri
Sphenoidal air sinus
LATERALLY
Temporal lobe with uncus
BELOW LATERALLY
Mandibular nerve
ANTERIORLY
Superior orbital fissure
Apex of the orbit
POSTERIORLY
Apex of the petrous
temporal bone
Crus cerebri of mid brain
21.
22. TRIBUTARIES
FROM THE ORBIT
Superior ophthalmic vein
Inferior ophthalmic vein
Central vein of retina
FROM THE BRAIN
Superficial middle cerebral
vein
Inferior cerebral vein
FROM THE MENINGES
Sphenoparietal sinus
Frontal trunk of middle
meningeal vein
STRUCTURES PASSING
THROUGH
LATERAL WALL
Occulomotor
Trochlear
Ophthalmic
maxillary
MEDIAL WALL
Internal carotid artery
Abducent nerve
23.
24. COMMUNICATIONS
With transverse sinus - via superior petrosal sinus
With internal jugular vein – through inferior
petrosal sinus and a plexus of veins around
internal carotid artery
With pterygoid venous plexus – through emissary
veins passing through foramen ovale, emissary
sphenoidal foramen and foramen lacerum
With opposite cavernous sinus- via anterior and
posterior intercavernous sinus
With facial vein by two routes-
- Superior ophthalmic vein and angular vein
- Pterygoid venous plexus and deep facial vein
25.
26.
27. CAVERNOUS SINUS THROMBOSIS
Septic thrombosis of cavernous sinus -by
communication from dangerous area of
face, orbit and pharynx
-severe pain in eye and forehead
-ophthalmoplegia due to involvement of 3rd
, 4th and 6th cranial nerves
- Marked oedema of eyelids
- exophthalmos
28. PULSATING EXOPHTHALMOS
Pulsating exophthalmos- internal carotid artery is
ruptured as a result of fracture of base of skull – arterio-
venous communication is established
- ligation of inernal carotid artery may be helpful, but
patient may develop contralateral hemiplegia
