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![After 21 centuries of scientific inquiry,
our understanding of cellular biology
has made significant progress, but the
percentage of nervous system cells for
which we fully understand all
functions is indeed relatively low
[almost 10%]. The 90%, are still under
exploration.](https://image.slidesharecdn.com/020csfandmeninges-251127195153-16a12942/75/CSF-and-meninges-CSF-and-meninges-CSF-and-meninges-pdf-1-2048.jpg)
Uploaded byProf. Dr. Ahmed Ashour
CSF and meninges/ CSF and meninges/ CSF and meninges.pdf
CSF and meninges
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- 1. After 21 centuriesof scientific inquiry, our understanding of cellular biology has made significant progress, but the percentage of nervous system cells for which we fully understand all functions is indeed relatively low [almost 10%]. The 90%, are still under exploration.
- 2. Ashour’s High YieldGuide USMLE Clinical Anatomy
- 3.
- 4. This study reportsa rare case of acute obstructive hydrocephalus following aqueductal stenosis. An 11-year-old boy admitted to the hospital with progressive headache, nausea and vomiting throughout a month.
- 5. A Computerized Tomography (CT)showed an obstructive hydrocephaly. A Magnetic Resonance(MR) imaging revealed a compressing the aqueduct. The patient deteriorated in hours and an emergency ventriculo-peritoneal shunting was performed. He did well in the early postoperative period.
- 7.
- 8. ILOs A. Describe theAnatomy and Function of the Meninges: Students will be able to describe the anatomy of the meninges, including the three protective layers surrounding the brain and spinal cord: the dura mater, arachnoid mater, and pia mater. They will understand the structure and function of each layer, including how they contribute to protecting the CNS and maintaining its structural integrity. B. Explain the Production and Circulation of Cerebrospinal Fluid (CSF): Students will be able to explain how cerebrospinal fluid (CSF) is produced by the choroid plexuses in the ventricles of the brain. They will describe the pathway of CSF circulation through the ventricular system, its flow through the subarachnoid space, and its reabsorption into the venous system via the arachnoid granulations. C. Describe the Role of CSF in Maintaining CNS Homeostasis: Students will be able to describe the role of CSF in maintaining CNS homeostasis, including its functions in cushioning the brain and spinal cord, removing metabolic waste products, and providing a stable chemical environment for neural tissue. They will understand how CSF helps to protect the CNS from mechanical injury and regulate intracranial pressure. D. Identify and Interpret Clinical Procedures Related to CSF and Meninges: Students will be able to identify and interpret clinical procedures related to CSF and the meninges, such as lumbar puncture (spinal tap) and imaging techniques like CT and MRI. They will understand how these procedures are used to assess CSF composition, measure intracranial pressure, and detect conditions affecting the meninges, such as meningitis or tumors.
- 9. While the meningesthemselves are not typically the direct target of surgical procedures, they play a crucial role in neurosurgery and other related interventions. The meninges are the protective layers surrounding the brain and spinal cord, consisting of the dura mater, arachnoid mater, and pia mater. The surgical importance of the meninges lies in their role as protective barriers and their involvement in certain medical conditions and procedure.
- 11. MENINGES A- Meninges ofthe spinal cord B- Meninges of the brain
- 12. The meninges arethree protective layers of tissue that surround and protect the central nervous system (CNS), which includes the brain and spinal cord. The three layers are: • Dura Mater: This is the tough, outermost layer. • Arachnoid Mater: Located beneath the dura, the arachnoid mater has a web- like structure. • Pia Mater: This is the innermost layer, closely adhering to the surface of the brain and spinal cord. Dura Arachnoid Pia
- 14. A- Meninges ofthe spinal cord Dura matter Arachnoid matter Pia matter
- 15. • Spinal Duramatter
- 16. ✓ It isthe outer & hardest layer ✓ Above, it is attached to the foramen magnum and it is continuing with the cerebral dura ✓ Throughout its length, it sends out sleeves around the' trunks of the spinal nerves ✓ Below, it extends beyond the lower end of spinal cord (L1/L2), it is attached to the 2nd sacral vertebra. 1 2 3 5 4 S1 S2
- 17.
- 18. ✓ Meningeal spaces: -Extradural (epidural) space: lies between the vertebral bone & the dura (external to dura), contains vertebral plexus of veins. - Subdural space: between the dura outside & the arachnoid, contains a thin film of fluid. Extra dural Sub-dural
- 19. Epidural block Anesthetic agentis injected into the extradural (epidural) space. It acts on the nerve roots and the sensation is lost inferior to the level of the block. Clinical Insight
- 20. • Spinal Arachnoidmatter
- 21. ✓ It isa thin transparent membrane. ✓ It lines the dura matter ✓ Above, it is attached to the foramen magnum and it is continuing with the cerebral arachnoid matter ✓ Below, it extends beyond the lower end of spinal cord (L1/L2), it is attached to the 2nd sacral vertebra. 1 2 3 5 4 S1 S2
- 22.
- 23. Subarachnoid ✓ Meningeal spaces: Arachnoidis separated from the pia matter by the subarachnoid space which contains the CSF.
- 24.
- 25. ✓ Lumbar cistern: Widepart of the subarachnoid space, distal to the caudal end of spinal cord. It Contains CSF, cauda equina and filum terminale. Lumbar cistern
- 26. Lumbar puncture In thelumbar puncture, the needle is introduced into the subarachnoid space, either above or below the tip of L4 spine. Clinical Insight 1 2 3 5 4
- 27. Lumbar puncture • Diagnosticuses: Obtaining C.S.F sample for analysis. • Therapeutic uses: Injection of local anesthetics and antibiotics. C.S.F withdrawal to decrease intra-cranial pressure. Clinical Insight
- 28. Lumbar puncture The needlepenetrates following layers: 1. Epidural space 2. Dura 3. Arachnoid 4. Subarachnoid space Clinical Insight 1 2 3 4
- 29. • Spinal Piamatter
- 30. ✓ It isa thin membrane firmly adherent to the spinal cord. ✓ Above, it is continuous with the pia matter of the brain. ✓ Below, it extends from the lower tip of spinal cord (L1/L2), to form the filum terminal which is attached inferiorly to the back of the coccyx. 1 2 3 5 4 Coccyx
- 31.
- 32. ✓ Filum terminal: oNon nervous filamentous thread about 20 cm long. o Attached • Above to tip of conus medullaris • Below blends with periosteum of coccygeal vertebra. filum terminal
- 33. Lumbar, sacral andcoccygeal nerves. Filum terminale.
- 34. o The filumterminal is surrounded with the cauda equina & arachnoid to reach the coccyx. Cauda equina
- 35. ✓ Denticulate ligament: Oneither side of the spinal cord, lateral margin of pia gives off 21 pairs of teeth like processes, which are attached to the dura mater for support of the spinal cord. At the sides of the spinal cord the pia gives attachment to the denticulate ligament Pia Denticulate ligament
- 36. B- Meninges ofthe brain Dura matter Arachnoid matter Pia matter
- 37. • Cerebral Duramatter
- 38. Composed of 2layers: A. Outer or endosteal layer B. Inner or meningeal layer Dura matter Outer or endosteal layer Inner meningeal layer
- 39. A- Outer orendosteal layer • Lines the cranial cavity & firmly adherent to the base of the skull but loosely attached to the vault. B- Inner or meningeal layer • Attached to the outer endosteal layer except at certain sites where it is reduplicated to form the dural folds. endosteal meningeal folds
- 40. Epidural (extradural) hematoma Ablow to the skull that results in a fracture can tear the underlying periosteal layer of dura mater, which can result in an epidural (extradural) hematoma and/or leakage of the cerebrospinal fluid. Clinical Insight
- 41. Subdural hematoma Subdural hematomais a medical condition characterized by the accumulation of blood between the dura mater (the outermost layer of the brain's protective coverings) and the arachnoid mater (the middle layer). Clinical Insight
- 42.
- 43. • crista galli •hypophyseal fossa • Posterior clinoid process • superior petrosal sulcus • petrous temporal bone • transverse sulcus • occipital bone • foramen magnum
- 44. Tentorium cerebelli • Definition: Itis a tent-shaped fold • Site: Between the cerebellum and the cerebrum Tentorium cerebelli
- 45. Attached border Posterior clinoidprocess superior petrosal sulcus Petrous bone transverse sulcus occipital bone • Attached border: ✓ Posterior clinoid process ✓ Lips of superior petrosal sulcus along the upper border of petrous temporal bone ✓ Lips of transverse sulcus at the occipital bone
- 46. • Free border ✓U-shaped ✓ Bounds the tentorial notch which transmits the midbrain. • Attached border • Free border
- 47. Falx cerebri • Definition: Itis a large sickle-shaped reduplication of the inner layer of dura mater • Site: Occupies the median longitudinal fissure between the two cerebral hemispheres Falx cerebri
- 48. • Features. o Apex:is narrow and is attached to the crista galli o Base: is broad and is attached to, the tentorium cerebelli in the median plane. A B
- 49. o Upper margin:is convex and is attached to the lips of the sagittal sulcus on the inner surface of the vault of the skull. o Lower margin: is concave and free, it encloses the inferior sagittal sinus . U L
- 50. Falx cerebelli • Definition: isa reduplication of the inner layer of the dura which projects forwards into the posterior notch of the cerebellum • Shape: Inverted triangle Falx cerebelli
- 51. • Features o Thebase: is directed upwards and is attached to the tentorium cerebeili in the median plane o The apex: is directed downwards till the foramen magnum tentorium cerebeili Falx cerebelli occipital sinus
- 52. o Posterior margin:encloses the occipital sinus o Anterior margin: is free and projects in the posterior notch of the cerebellum tentorium cerebeili Falx cerebelli occipital sinus
- 53. Diaphragma sellae Is asmall circular fold of the inner layer of the dura which covers the pituitary in the hypophyseal fossa. Has a central aperture which transmits the pituitary pituitary hypophyseal fossa
- 54. • Cerebral Arachnoidmatter
- 55. o It isa delicate transparent membrane bridging over the brain. o It forms a sheath around the cranial nerves at their exit from the skull. o It forms the arachnoid villi & granulation. o It is separated from the pia matter by the subarachnoid space which contain CSF. Villi – granult. Arachnoid Subarachn. space
- 56. o Arachnoid villi& granulation A mass of granulation tissue that pierce the dura & become in relation to the superior sagittal sinus where it drain C.S.F in the venous blood. Arachnoid granulation Arachnoid villi dura superior sagittal sinus
- 57. In advanced age,these granulations becomes calcified & indent the bone of the skull forming pits in the bone (Granular foveolae). granular foveolae
- 58. Subarachnoid hemorrhage The mostcommon cause of subarachnoid hemorrhage (bleeding into the subarachnoid space) is the rupture of a saccular, or berry, aneurysm of one of the arteries of the cerebral and brainstem circulation. Berry aneurysms commonly occur at artery branch points with about 85% occurring between the anterior cerebral, internal carotid, and middle cerebral branches. Clinical Insight
- 59. • Cerebral Piamatter
- 60. Cerebral pia matteris a thin vascular layer firmly adherent to the surface of the brain. Cerebral pia matter covers the bulging gyri and the floor of the sulci. Dura Arachnoid pia
- 61.
- 62. The volume ofcerebrospinal fluid (CSF) in the human central nervous system is approximately 150 milliliters. Totally replaced 3 times per day.
- 63. Dura Arachnoid Pia 3 rd ven. 4th ven. Ter. ven. Centralcanal of spinal cord Choroid Plexus Interventricular foramen Cerebral aqueduct of Sylvius Foramen Luschka Dural venous sinus Lateral ven. Lateral ven.
- 64. • Definition: Cerebrospinal fluid(CSF) is a clear, colorless fluid found within and around the brain and spinal cord of all vertebrates.
- 65. • Formation: Secreted bychoroid plexuses in all the ventricles of the brain. The choroid plexus filters blood plasma and secretes CSF into the ventricles. Choroid Plexus, is made of a layer of cuboidal epithelial cells around a capillary core
- 66. • Circulation: From thelateral ventricles to the 3rd ventricle through the interventricular foramen (foramina of Monro). Interventricular foramen
- 67. RT. Lateral ventricleAnt. Pole RT. Foramen of Monro Third ventricle cerebral aqueduct of Sylvius 4th ventricle Luschka Magendie Central canal spinal cord Terminal ventricle
- 68. From the 3rdto 4th ventricle through the cerebral aqueduct Cerebral aqueduct
- 69. From the foraminaof the 4th ventricle (Magendi, Lushka) to the subarachnoid space around brain and spinal cord. Small amount goes to central canal of the spinal cord. Lushka Magendi central canal
- 70. • Drainage ofthe C.S.F The C.S.F is filtered into the superior sagittal sinus by arachnoid villi and granulation. arachnoid villi and granulation superior sagittal sinus
- 72. Hydrocephalus Obstruction of thedrainage system leads to distension of the ventricles, a case called hydrocephalus. Clinical Insight
- 73. Type of Hydrocephalus Description Noncommunicating Obstruction offlow within ventricles; most commonly occurs at narrow points, e.g., foramen of Monro, cerebral aqueduct, openings of the fourth ventricle Communicating Impaired CSF reabsorption in arachnoid granulations or obstruction of flow in subarachnoid space Normal pressure (chronic) CSF is not absorbed by arachnoid villi (a form of communicating hydrocephalus). CSF pressure is usually normal. Ventricles chronically dilated. Produces triad of dementia, apraxic (magnetic) gait, and urinary incontinence. Peritoneal shunt.
- 74. Hydrocephalus This condition occurswhen excess cerebrospinal fluid (CSF) collects in the brain’s ventricles. Obstructive (noncommunicating) hydrocephalus Etiology: • Blockage at any point in the ventricular system • Stenosis of the cerebral aqueduct (of Sylvius) Clinical Insight
- 75. Hydrocephalus Communicating hydrocephalus Etiology: • Oversecretion of CSF • Impaired of CSF absorption from the subarachnoid space. Clinical Insight
- 76. Normal pressure hydrocephalus NPHis a type of communicating hydrocephalus caused by impaired cerebrospinal fluid absorption. It manifests with a classic triad of symptoms: • Urinary incontinence • Gait disturbance • Cognitive decline. Clinical Insight
- 77. Ventriculo-peritoneal (VP) shunt isa medical device that relieves hydrocephalus A ventriculo-peritoneal shunting is a surgical procedure that primarily treats hydrocephalus. Doctors surgically place VP shunts inside one of the brain’s ventricles to divert fluid away from the brain and restore normal flow and absorption of CSF. Clinical Insight
- 78.
- 79. Q1: How dothe meninges cover the spinal cord? - The pia, arachnoid, and dura cover the spinal cord in tight, closely apposed layers. - The dura, arachnoid, and pia of the brain and spinal cord are continuous. All three layers loosely cover the spinal cord. - The dura, arachnoid, and pia all cover the spinal cord; the dura and arachnoid are tightly connected with each other. - Only the dura mater continues down from the brain to cover the spinal cord
- 80. Q2: The spinalpia forms collagenous ligaments that anchor it to the dura. These are the denticulate ligaments. What is their spatial relationship to the dorsal and ventral roots? - The denticulate ligaments form a scalloped series of attachments between the ventral and dorsal roots in the cervical regions. - The denticulate ligaments are located below the dorsal roots - The denticulate ligaments are located above the dorsal roots. - The denticulate ligaments attach between the exits and entrances of the ventral and dorsal roots
- 81. Q3: A 42-year-oldman presents with persistent headaches that are not alleviated by ibuprofen. Brain imaging reveals noncommunicating hydrocephalus. What is the most accurate statement? A. Flow of cerebrospinal fluid is likely impaired at arachnoid granulations. B. Flow of cerebrospinal fluid is likely not obstructed. C. Flow of cerebrospinal fluid is likely obstructed at cerebral aqueduct. D. There is too much cerebrospinal fluid in his brain. E. There is too much glucose crossing the blood-brain barrier.
- 82. Q4: If itwere necessary, as it sometimes is, to insert a needle into the subarachnoid space to sample CSF, where is a relatively safe point for needle insertion? A. Between C-7 and T-1. B. Between L-3 and L-4. C. Between L-1 and L-2. D. Between T-12 and L-1.
- 83. Q5: A 78-year-oldman comes to the physician for evaluation after a fall. His history is significant for worsening urinary incontinence and memory loss over the past 4 months with wide-based gait with short steps and bradykinesia without tremor. Funduscopic examination is normal. Serum thyroid- stimulating hormone is 2.2 mIU/L. Which of the following conditions is the most likely cause of this patient’s recent decline? Alzheimer disease Hypothyroidism Multi-infarct dementia Normal pressure hydrocephalus
- 84. Q6 How dothe meninges cover the spinal cord? -The pia, arachnoid, and dura cover the spinal cord in tight, closely apposed layers. -The dura, arachnoid, and pia of the brain and spinal cord are continuous. All three layers loosely cover the spinal cord. -The dura, arachnoid, and pia all cover the spinal cord; the dura and arachnoid are tightly connected with each other. -Only the dura mater continues down from the brain to cover the spinal cord, protecting it from the surrounding bone.
- 85. Q7 A 4-month-oldinfant is brought to the hospital with irritability, high fever, and bulging fontanelle. The pediatrician suspects meningitis and plans a lumbar puncture to obtain cerebrospinal fluid for diagnostic testing. Considering the anatomical differences in the infant’s spinal cord termination compared to adults, the safest site for needle insertion is: A. Between L-4 and L-5 B. Between L-3 and L-4 C. Between T-12 and L-1 D. Between C-7 and T-1
- 86. Q8 A 22-year-oldman presents with a severe headache and photophobia. A lumbar puncture confirms bacterial meningitis, with purulent CSF. The infection primarily involves the leptomeninges, which include two closely associated layers. Which two meningeal layers form the leptomeninges? A. Dura mater and arachnoid mater B. Arachnoid mater and pia mater C. Periosteal dura and meningeal dura D. Pia mater and dura mater E. Subarachnoid and subdural spaces
- 87. Q9 A neonateis born with Arnold-Chiari malformation, which obstructs the foramina of Luschka and Magendie, leading to hydrocephalus. CSF accumulates in the ventricles due to impaired outflow. These foramina normally allow CSF to exit the fourth ventricle into which space? A. Central canal B. Subdural space C. Epidural space D. Subarachnoid space E. Cisterna magna only
- 88. Q10 A 60-year-oldman develops symptoms of normal pressure hydrocephalus, including urinary incontinence and gait disturbance. Imaging reveals dilated ventricles without obstruction. This condition is often due to impaired absorption of CSF by which anatomical structure? A. Central canal B. Choroid plexus C. Arachnoid villi D. Dural sinus valves E. Foramen of Monro
- 89. Q11 During alumbar puncture in a patient, at the L3–L4 level, the needle passes through several layers before reaching the CSF. After piercing the dura mater, it enters which space that contains cerebrospinal fluid? A. Epidural space B. Subdural space C. Subarachnoid space D. Central canal E. Arachnoid villi
- 90. Q12 Following headtrauma, a patient develops a crescent-shaped hemorrhage on CT that crosses suture lines but not midline. This is most consistent with a subdural hematoma, typically caused by tearing of which structure bridging the subarachnoid space and dura mater? A. Emissary veins B. Arachnoid granulations C. Bridging cerebral veins D. Superior sagittal sinus E. Falx cerebri A B C D E
- 91. Q13 A patientwith a skull fracture involving the pterion develops an epidural hematoma. The bleeding is due to laceration of which artery, which lies between the skull and the dura mater? A. Internal carotid artery B. Middle cerebral artery C. Posterior cerebral artery D. Middle meningeal artery E. Vertebral artery
- 92. Q14 A patientpresents with papilledema and elevated intracranial pressure. Imaging shows obstructive (non- communicating) hydrocephalus caused by a mass in the interventricular foramen (foramen of Monro). This obstruction would block CSF flow between which two structures? A. Lateral ventricles and third ventricle B. Third and fourth ventricles C. Fourth ventricle and subarachnoid space D. Cerebral aqueduct and fourth ventricle E. Central canal and spinal cord
- 93. Q15 A 6-month-oldinfant with congenital aqueductal stenosis undergoes placement of a ventriculo-peritoneal (VP) shunt to relieve hydrocephalus. The neurosurgical team inserts the proximal catheter into a cerebral ventricle. The catheter is commonly placed through a hole into the frontal horn of which ventricle ? A. Third ventricle B. Fourth ventricle C. Cerebral aqueduct D. Lateral ventricle E. Central canal
- 94.
- 95. Q1: The dura,arachnoid, and pia ------- are tightly connected with each other. Q2: The denticulate ligaments attach -----entrances of the ventral and dorsal roots Q3: Flow of cerebrospinal fluid is likely obstructed at the cerebral aqueduct. Q4: Between L-3 and L-4. Q5: Normal pressure hydrocephalus Q6 The dura, arachnoid, and pia -------- tightly connected with each other. Q7 Between L-4 and L-5 Q8 Arachnoid mater and pia mater Q9 Subarachnoid space Q10 Arachnoid villi Q11 Subarachnoid space Q12 Bridging cerebral veins Q13 Middle meningeal artery Q14 Lateral ventricles and third ventricle Q15 Lateral ventricle
- 96. List of Textsand Recommended Readings • Last's Anatomy, Regional and Applied. Chummy S. Sinnatamby. 12th edition 2011, ISBN:13 - 978 0 7020 3394 0 (Available in ClinicalKey: https://www.clinicalkey.com/#!/browse/book/3-s2.0- C2009060533X) • Estomih Mtui, Gregory Gruener and Peter Dockery. Fitzgerald's Clinical Neuroanatomy and Neuroscience. 7th edition; 2016, ISBN: 13 - 978-0-7020- 6727-3 (Available in ClinicalKey: https://www.clinicalkey.com/#!/browse/book/3-s2.0- C20130134113 • Drake, Richard L. Gray's Anatomy for Students, Third Edition, Elsevier Saunders 2015. ISBN-13: 978-0702051319 (Available in ClinicalKey: https://www.clinicalkey.com/#!/browse/book/3- s2.0-C20110061707). • Sobotta Atlas of Human Anatomy. F. Paulsen. Vol.1, 15th Edition; 2013, ISBN: 9780702052514 (Available in ClinicalKey: https://www.clinicalkey.com/#!/content/book/3- s2.0-B9780702052514500067) • Sobotta Atlas of Human Anatomy. F. Paulsen. Vol.2, 15th Edition; 2013, ISBN:13 - 978-0-7020-5252-1 (Available in ClinicalKey: https://www.clinicalkey.com/#!/browse/book/3- s2.0-C20130046919)
- 97.