1. The document discusses the meninges, cerebral spinal fluid, and dural venous sinuses. It describes the three meningeal layers - dura mater, arachnoid mater, and pia mater. 2. It then provides details on the various dural venous sinuses, including their locations, tributaries, and drainage. Key sinuses discussed include the superior sagittal sinus, straight sinus, transverse sinus, sigmoid sinus, and cavernous sinus. 3. The document also covers cerebral spinal fluid, including its composition and functions. The choroid plexus is described as actively secreting CSF in the ventricles.

1. Dr. NDAYISABA CORNEILLE
CEO of CHG
MBChB,DCM,BCSIT,CCNA
THE MENINGES,CEREBRAL SINAL
FLUID.
Supported BY

2. MENINGES
• Encloses the brain and spinal cord
• Include;
• the dura mater,
• arachnoid mater,
• pia mater.
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3. The dura mater
• Consists of the
-outer periosteal layer: attached to the inner
periosteum of the skull and continuous on the
outside through the foramen magnum
-inner meningeal layer: in contact arachnoid
mater and continuous with the spinal dura
through the foramen magnum.
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4. Cont’n
• The layers of dura mater separate to form dural
partitions and coatings of the intracranial venous
structures.i.e.
• falx cerebri: projects downward btn two cerebral
hemispheres, anteriorly attached to the ethmoid
bone and posteriorly blends with tentorium
cerebelli.
• Tentorium cerebelli: separates the cerebelli from
the cerebral hemispheres posterioly.Attached
posterioly to occipital bone and laterally to the
temporal bone.ant & lat forms a tentorium notch.
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5. Cont’n
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6. Cont’n
• Falx cerebelli: projects btn two cerebellar
,attached to the internal occipital crest
posteriorly and superiorly to the tentorium
cerebelli
• Diaphragm sellae: this covers the hypophysial
fossa of the sellae turcica
Arterial supply-anterior meningeal artery
-middle and accesory meningeal
artery (most important because its susceptible to
injury )
-posterior meningeal artery
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7. Cont’n
• Venous supply
Meningeal veins, lie lateral to the arteries,
middle meningeal vein drains into the
sphenoparietal sinus.
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8. Cont’n
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9. Cont’n
• Innervation: trigeminal (v1,v2 ,&v3)vagus and
the first three cervical nerves.
• Anterior/falx cerebri & tentorium cerebelli:
meningeal branches from ethmoidal
nvs(ophthalmic nerve,v1)
• Middle:maxillary nerve v2,and mandibular nv
v3 laterally
• Posterior:first to third cervical nvs.
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10. Arachnoid mater
• Is a thin avascular & impermiable layer that
lies btn the dura and the pia
• Separated from dura and pia by a subdural
space and subarachnoid space respectively.
• Projects into venous sinuses to form arachnoid
villi which when agregated form the arachnoid
granulations.(sites for csf diffuson into the
blood stream)
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11. Pia mater
• It’s a vascular mebrane that closely covers the brain
,the gyri deep to the sulci. fuses with the nv
epineurium.
• Clinical Importance: intracranial heamorrhage
• Extradural heamorrhage: arterial or venous injury,the
middle meningeal artery is mostly injured.
• Subdural heamorrhage: damage to the superior
cerebral veins.
• Subarachnoid heamorrhage: rapture of congenital
anuerysms of the circleof willis.
• meningitis
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15. • 15th of all primary tumours
• Slow growing and benign
• Arise from leptomeninges and cells of
arachnoid granules
MENINGIOMA
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17. CSF
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18. Cerebral Spinal Fluid
• Found in the ventricles and subarachnoid
spaces of the brain and spinal fluid.
• Its clear,colourless with same inorganic salt
content as blood.(150ml)
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19. Cont’n
Functions of the Cerebrospinal Fluid
• Cushions and protects the central nervous system from
trauma
• Provides mechanical buoyancy and support for the
brain
• Serves as a reservoir and assists in the regulation of the
contents of the skull
• Nourishes the central nervous system
• Removes metabolites from the central nervous system
• Serves as a pathway for pineal secretions to reach the
pituitary gland
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20. Cont’n
The Physical Characteristics and Composition of the CSF
• Appearance Clear and colorless
• Volume c. 150 mL
• Rate of production 0.5 mL/minute
• Pressure (spinal tap with patient in lateral recumbent
position) 60–150 mm of water
Composition
• Protein 15–45 mg/100 mL
• Glucose 50–85 mg/100 mL
• Chloride 720–750 mg/100 mL
• Number of cells 0–3 lymphocytes/cumm
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21. Cont’n
• Formation: the choroid plexus actively secrets
csf in the ventricles and neuronal metabolites
from csf into blood
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22. a
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23. Sinuses of duramater
• Superior sagittal sinus
• Inferior sagittal sinus
• Straight sinus
• Confluence of sinus
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24. • Transverse sinus
• Sigmoid sinus
• Superior petrosal sinuses
• inferior petrosal sinuses
• Cavernous sinus
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25. Cavernous sinus
Sup. ophthalmic v.
Inf. ophthalmic v.
(not shown)
Central v. of retina
(inside optic n.)
Sphenoparietal
sinus
Superficial
middle cerebral v.
Drainage
Tributaries
Sup. petrosal
sinus
Inf. petrosal
sinus
Intercavernous sinus
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26. Sup. petrosal sinus
Inf. petrosal sinus
Sigmoid sinus
To int. jugular v.
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27. a
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28. • All lie between inner and outer layers of dura
except the inferior sagittal and straight sinuses
• Receive blood from brain and bone
• Lack muscular coat
• Lined by endothelium (thin)
• Valveless, hence blood can floor in either
direction
Characterstics of dural venous sinuses
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29. Image of dural sinuses
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30. • Lies between 2 layers of falx cerebri along its
attached margin
• Commences at foramen caecum, widens
towards internal occipital protuberance
• 3-4 lakes of blood project laterally from it
Superior sagittal sinus
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31. • Receives blood from upper and posterior parts
of both medial and lateral surfaces of both
hemispheres but not frontal pole
• Turns at internal occipital protuberance,
mostly to the right to become the transverse
sinus
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32. • Begins just posterior to crista galli
• Lies between free margin of falxi cerebri layers
• Drains inferior parts of medial surfaces of both
hemispheres
• flows into straight sinus at
attachment/junction of falx cebri and
tentorium cerebelli
Inferior sagittal sinus
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33. • Lies between folds of fibrous dura at junction
of falx cerebri and tentorium cerebelli
• Receives inferior sagittal sinus and great
cerebral vein of Galen, veins from adjoining
occipital lobes , upper surface of cerebellum
• Ends in internal occipital protubarence by
turning into the transverse sinus usually on
the left
Straight sinus
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34. • Commences at internal occipital protuberence
between layers of attached margin of
tentorium cerebelli
• Courses horizontally forwards
• Curves downwards at the junction of petrous
and mastoid parts of temporal bone as
sigmoid sinus
• Right usually larger than left because it
receives sagittal sinus
Transverse sinus
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35. • Transverse sinuses communicate at their
commencement at internal occipital
protuberance
• Receive tributaries from nearby surfaces of
cerebral and cerebellar hemispheres and
sagittal sinus
Cont/…
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36. • Commences at termination of transverse sinus
• Curves downwards then forwards to posterior
margin of jugular foramen , passes through
and expands into superior jugular bulb
• Internal jugular vein emerges from it
Sagittal sinus
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37. • Is connected to exterior in its upper part by
mastoid emissary vein which joins posterior
auricular vien
• In the lower part by a vein that passes through
posterior condylar foramen to suboccipital
plexus of veins
• Around margins of foramen magnum a pair of
sinuses communicate with internal vertebral
plexus
Sigmoid sinus
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38. • Runs inferiorly from commencement of
transverse sinus through foramen magnum,
skirts margin of foramen and drains into the
sigmoid sinus
• Receives tributaries from cerebellum and
medulla
• Drains choroid plexus of fourth ventricle
Occipital sinus
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39. • Lies alongside body of sphenoid bone in
middle cranial fossa
• Receives blood from orbit, vault bones and
cerebral hemisphere
• Drains by superior and inferior petrosal
sinuses to transverse sinus and IJV
respectively
• Connected to pterygoid plexus by emissary
veins
Carvenous sinus
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40. Cont/…
• Blood flows in either direction depending on
local venous pressures.
• It has no valves and so do veins connected to
it.
• It is a plexus of veins and not a trabeculated
venous space as its name suggests
• Size 2cm (L) x 1cm (W)
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41. Image of cavernous sinus - dorsal view
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42. • Lies in the space between periosteum of body
of sphenoid and a fold of the inner layer of
dura which forms roof, lateral walls and
superior part of medial wall
• Medially, roof continuous with diaphragma
sellae
• Extends from apex of orbit anteriorly to
back/apex of petrous part of temporal bone
posteriorly
Boundaries / location
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43. • Lateral-medial surface of temporal bone and
uncus of temporal lobe
• Floor – Greater wing of sphenoid
Cont/…
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44. Relations
• Anterior; apex of orbit
• Lateral; anterior part of trigeminal ganglion,
temporal lobe of cerebral hemisphere
• Posteroinferior part of lateral wall; trigeminal
(Meckel’s) cave
• Posterior; apex of petrous temporal bone
• Medial; body of sphenoid bone
• Superior; internal carotid aa, uncus of temporal lobe
• Inferior; greater wing of sphenoid
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45. Contents
Structures lying within the cavity:
• Internal carotid aa
• Abducent nn
Structures embedded within the lateral wall:
• CN III
• CN IV
• CN V- ophthalmic and maxillary divisions
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46. Cont/…
• Internal carotid artery and abducent nerve run through the
sinus
• Oculomotor and trochlear nerves and ophthalmic and
maxillary divisions of trigeminal nerve lie in the lateral wall of
the sinus
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47. Qn a. What are the tributaries to
the cavernous sinus?
b. What veins directly drain
the cavernous sinus?
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48. Veins of the cavernous sinus
• Characterised by bidirectional floor
• Front;
-Superior ophthalmic vein
-Inferior ophthalmic vein
• Roof;
-Superficial middle cerebral vein
-Shenoparietal sinus
• Back;
-superior petrosal sinus
-inferior petrosal sinus (larger and empties the bulk of
blood from cavernous sinus)
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49. Cont/…
• Floor;
- emissary veins which communicate with the
pterygoid venous plexus
• Medial;
- intercavernous sinus
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50. Cavernous sinus and connections
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51. Sup. ophthalmic v.
Inf. ophthalmic v.
Cavernous sinus
Angular v.
Facial v.
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52. Sup. labial v.
Facial v.
Angular v.
Sup. ophthalmic v.
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53. Cavernous sinus Optic chiasm
Hypophysis
Sphenoid sinuses
within body of sphenoid bone
Similarities with
other sinuses
Within dura
Differences from
other sinuses
Lined by endothelium
Lacks muscular coat
Lacks valves
III
IV
V1
V2
VI
Int. carotid a.
(w/sympathetic plexus)
Contains
trabeculae
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54. The flowing of the blood in dural sinus
Sup. sagittal sinus
Inf. sagittal sinus Straight sinus Confluence of sinus Transverse sinus
Cavernous sinus
Sup. petrosal sinus
Inf. petrosal sinus Internal jugular vein
Sigmoid sinus
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55. Danger triangle of the face
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56. CASE
HISTORY
 Patient develops a boil on his upper lip after cutting
himself shaving on a hunting trip
 He presents to his physician with a high fever and
severe headaches
 Patient does not improve with penicillin injections and
is admitted to a hospital
EXAMINATION
 Rigidity of neck muscles
 Upper lip swollen and oozing pus
 Cheek, side of nose and eyelids swollen
 Exophthalmos
 Edema of optic nerve at papilla
 Inability to move eye
 Paresthesia of forehead, side of nose and upper cheek
 Blood culture positive for Staphylococcus aureus
DIAGNOSIS ???
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57. • Carvenous sinus thrombosis from danger area of
the face, can spread to dural sinuses and eyes
• Veins exit thru- inferior petrosal sinus
• Emissary veins
• Pterygoid plexus
• Inferior ophthalmic
• Deep facial vein
Qn. In the above case, ocular symptoms were
initially unilateral, but later became bilateral.
Provide an explanation
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58. Sup. labial v.
Facial v.
Angular v.
Sup. ophthalmic v.
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59. • Only anatomic location in the body where an
artery travels completely through venous
structure
• Rupture of ICA within the sinus- ateriovenous
fistula ie carotid –carvenous fistula
• Pituitary gland lies between two paired
carvenous sinuses – pituitary adenoma will
compress the sinus—ophthalmoplegia,
ophtalmic sensory loss
Clinical significance
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60. END
DR NDAYISABA CORNEILLE
THANKS FOR LISTENING
By
DR NDAYISABA CORNEILLE
MBChB,DCM,BCSIT,CCNA
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