This document discusses the anatomy and physiology of the meninges and cerebrospinal fluid (CSF). It describes the three layers of meninges - dura mater, arachnoid mater, and pia mater. It also discusses the blood-brain barrier, dural venous sinuses, ventricular system, CSF production and composition, changes in CSF in disease like meningitis, causes and clinical presentation of meningitis, and management of meningitis.

1. Oh you who believe, stay away from bad suspicion (Al - Hujurat )

2.  Describe topographic Anatomy of Meninges
• Innervation
• Blood supply
 Describe the Blood Brain Barrier (BBB)
 Enlist Dural Venous Sinuses & with their
function
 Role of Ventricular system in CSF
production, circulation
 Interpret CSF report in case of meningitis
 What is the causes , Clinical presentation
consequences & management of meningitis

3. Meninges
 Three layers of tissue covering brain & spinal cord:
Dura mater
Arachnoid mater
 Pia mater
 Two spaces:
Subdural space
Sub-arachnoid space

4. Dura Matter
Tough, dense connective
tissue, extends to 2nd
sacral vertebra
 Divides into two layers:
 Periosteal layer
Meningeal layer

5. Falx cerebri
Tentorium cerebelli
Falx cerebelli
Having 4 folds
Diaphragma sellae

6. Arachnoid Matter
 Thin layer, pressed
against inner wall of
Dura by
cerebrospinal fluid
pressure in
subarachnoid
space

7. Pia Matter
 Lies on surface of brain &
spinal cord

8. Dural
Nerve
Supply
 Branches of the trigeminal, Vagus, and
first three cervical nerves and branches
from the sympathetic system pass to the
dura.
 The dura is sensitive to stretching, which
produces the sensation of headache.

9. Dural Arterial Supply
The Dura matter’s arteries supply
from:
Dural Blood Supply
 Internal carotid
 Maxillary
 Ascending pharyngeal
 Occipital
 Vertebral arteries.
From a clinical point, the most
important is the middle meningeal
artery(branch of Maxillary), which is
commonly damaged in head
injuries.
Dural Venous Drainage
 The meningeal veins lie in the
endosteal layer of dura.
 The middle meningeal vein
follows the branches of the
middle meningeal artery and
drains into:
• Pterygoid venous plexus
or
• Sphenoparietal sinus.
 The veins lie lateral to the
arteries.

10. Dural Venous Sinuses
 Their main function is to drain CSF
Sinus Drain into
• superior sagittal sinus confluence of sinuses
• inferior sagittal sinus unites with great cerebral vein to form straight
sinus
• straight sinus confluence of sinuses
• confluence of sinuses transverse sinuses
• transverse sinus sigmoid sinus
• sigmoid sinus internal jugular vein
• cavernous sinus superior & inferior petrosal sinuses
• occipital sinus confluence of sinuses
• inferior petrosal sinus internal jugular vein
• superior petrosal sinus sigmoid sinus

13. Physiology of BBB
 In the brain, endothelial cells are packed
much tighter together due to the existence of
tight junctions between them, blocking the
passage of most molecules.
 The BBB blocks most of the molecules except
those that cross cell membranes by means of
lipid solubility (like steroid hormones, oxygen,
carbon dioxide) and those that are allowed
by specific transport systems (like sugars and
some amino acids)

15. Condition in which BBM disturb
The BBB can be disturb by:
 Hypertension
 Hyper osmolality
 Radiation
 Infection
 Trauma
 Inflammation
 Pressure

16. Ventricular System
 Ventricle is an internal cavity
of the brain which is filled
with CSF.
Composed of:
 Two lateral ventricles
 Third ventricle
 Fourth ventricles

17.  All these ventricles are
connected through:
 Foramen Monro
Cerebral Aqueduct
 Foramen Magendie
 Foramen Luschka

18.  Formed by Choroid
Plexus
 Plexus is formed by
invaginating of vascular
pia mater into the
ventricular cavity
 It becomes highly
convoluted & produce a
spongy-like appearance
 It enters the 3rd and 4th
ventricles through their
roofs, and the lateral
ventricles through the
choroid fissure
C
S
F
Choroid plexuss

19. Appearance & Composition of the CSF
Appearance Clear and colourless
Volume 130 ml
Rate of production 0.5 ml/min
Pressure 60-180 mm of H2O
Composition
protein 15-45 mg/ dL
glucose 50-85 mg/ dL
chloride 720-750 mg/100 ml
No. of cells 0-5 lymphocytes/μL

20. Changes In Composition In Disease
Bacterial Meningitis Tubercular Meningitis
Glucose (mg/dL):
Normal to marked
decrease. <40
mg/dL.
Protein (mg/dL)
(Marked increase) >
250 mg/dL.
WBCs (cells/μL)
>500 (usually >
1000). Early: May be
< 100.
Cell differential:
Predominance of
Neutrophils (PMNs)
Culture: Positive
Opening Pressure Elevated
Glucose (mg/dL): <40 mg/dL (Low)
Protein (mg/dL)
(moderate to marked
increase) 50 -500
mg/dL
WBCs (cells/μL)
Variable (10 -1000
cells/μL) <500cells/μL.
Cell differential:
Predominance of
Lymphocytes
Culture: Positive for AFB
Opening Pressure Variable

21. Meningitis
Inflammation of the meninges
Common causes of meningitis include:
 Bacteria
 Virus
 Fungi
 Parasites.

22. Organisms Causes Meningitis
 Birth to 4 weeks: GBS, E.coli
 4 to 12 weeks: GBS, E.coli, Pneumococcus,
Salmonella, Listeria, H. Influenza
 3 months to 3 years: Pneumococcus,
Meningococcus, H. Influenza
 3 years to adult: Pneumococcus, Meningococcus

23. Pathogenesis
 Infection of upper respiratory tract
 Invasion of blood stream
 Seeding & inflammation of meninges
 Increase in ICP due to inflammatory exudate

24.  Headache
 Fever
 Irritability
 Lethargy
 Poor feeding(in child)
 Convulsions
 Photophobia

25. consequences
 Hydrocephalus
 Spinal & cranial nerve palsy
 Hearing loss
 Cortical blindness
 Seizures
 Intellectual deficit

26. Management
 Lumbar Puncture
 Antibiotic