View source for Meninges

{{Short description|Three membranes protecting the brain}}
{{redirect|Meninx|the Tunisian archaeological site|Meninx (town)}}
{{Infobox anatomy
| Name        = Meninges
| Latin       = meninges
| Greek       =
| Image2       = Meninges-en.svg
| Caption2     = The meninges: dura mater, arachnoid mater and pia mater
| Width       =
| Image       = 3D Medical Illustration Meninges Details.jpg
| Caption     = Image depicting meninges around the brain
| Precursor   =
| System      =
| Artery      = [[Middle meningeal artery]], [[meningeal branches of the ascending pharyngeal artery]], [[accessory meningeal artery]], branch of [[anterior ethmoidal artery]], [[meningeal branches of vertebral artery]]
| Vein        =
| Nerve       = [[Middle meningeal nerve]], [[nervus spinosus]]
| Lymph       =
}}

In [[anatomy]], the '''meninges''' ({{IPAc-en|m|ə|ˈ|n|ɪ|n|dʒ|iː|z}};<ref>{{cite web |title=meninges |url=https://oxfordlearnersdictionaries.com/definition/english/meninges |website=Oxford Learner's Dictionaries}}</ref><ref>{{cite Merriam-Webster|meninges |access-date=2012-07-28}}</ref> {{singular}} '''meninx''' {{IPAc-en|ˈ|m|iː|n|ɪ|ŋ|k|s|,_|ˈ|m|ɛ|n|ɪ|ŋ|k|s}};<ref>{{cite Merriam-Webster|meninx |access-date=2012-07-28}}</ref> {{etymology|grc|''{{wikt-lang|grc|μῆνιγξ}}'' ({{grc-transl|μῆνιγξ}})|membrane}})<ref>{{LSJ|mh{{=}}nigc|μῆνιγξ|ref}}</ref> are protective [[membrane]]s that cover the [[brain]] and [[spinal cord]].  In [[mammal]]s, three meninges have been clearly identified: the [[dura mater]], the [[arachnoid mater]], and the [[pia mater]]. Each layer has its own molecularly distinct type of [[fibroblasts]].<ref name="Betsholtz">{{cite journal |last1=Betsholtz |first1=C |last2=Engelhardt |first2=B |last3=Koh |first3=GY |last4=McDonald |first4=DM |last5=Proulx |first5=ST |last6=Siegenthaler |first6=J |title=Advances and controversies in meningeal biology. |journal=Nature Neuroscience |date=November 2024 |volume=27 |issue=11 |pages=2056–2072 |doi=10.1038/s41593-024-01701-8 |pmid=39333784 |pmc=11862877 |url=https://escholarship.org/uc/item/7sx757mx }}</ref> The meninges act as a physical and immunological protective barrier for the brain and spinal cord, shielding the [[central nervous system]] (CNS) from injury.<ref name="Levy" /> They anchor and support  the tissues of the CNS, and provide containment for cerebrospinal fluid (CSF) and the arteries and veins that supply blood to the brain and spinal cord.<ref>{{cite web |last1=Castillero Mimenza |first1=Oscar |date=January 2017 |title=Meninges: anatomía, partes y funciones en el cerebro |url=https://psicologiaymente.com/neurociencias/meninges}}</ref>

The dura mater surrounds the arachnoid mater and supports the [[dural sinuses]], which carry blood from the brain to the heart.<ref name="Dasgupta" /> The area between the arachnoid and pia mater is known as the subarachnoid space. It contains [[cerebrospinal fluid]]. The arachnoid and pia maters produce [[prostaglandin D2 synthase]], a major cerebrospinal fluid protein.<ref name=":1" /> The arachnoid mater provides a restrictive permeability barrier between the cerebrospinal fluid in the subarachnoid space and the circulation of blood in the dura.<ref name="Betsholtz" />  The pia mater is a thin sheet of connective tissue that interfaces with the glial limitans superficialis.<ref name="Levy" />

==Structures==
===Dura mater===
{{Main|Dura mater}}

The dura mater ({{langx|la|tough mother}}),<ref>{{cite dictionary|url=https://www.merriam-webster.com/dictionary/dura+mater|title=Definition of dura mater|dictionary=[[Merriam-Webster]] Online Dictionary|access-date=22 June 2022}}</ref>{{Efn|Also rarely called ''meninx fibrosa'' or ''pachymeninx''}} is a durable, thick fibrous membrane that attaches to the inside of the [[skull]] and covers the brain and vertebrae. Its dense fibrous tissue is formed from an interlay of collagen fibers, elastin, and fibroblasts in an unformed extracellular matrix.<ref>{{Cite journal |last1=Niestrawska |first1=JA |last2=Rodewald |first2=M |last3=Schultz |first3=C |last4=Quansah |first4=E |last5=Meyer-Zedler |first5=T |last6=Schmitt |first6=M |last7=Popp |first7=J |last8=Tomasec |first8=I |last9=Ondruschka |first9=B |last10=Hammer |first10=N |date=2023-10-15 |title=Morpho-mechanical mapping of human dura mater microstructure |url=https://www.sciencedirect.com/science/article/pii/S1742706123004865 |journal=Acta Biomaterialia |volume=170 |pages=86–96 |doi=10.1016/j.actbio.2023.08.024 |pmid=37598794 |issn=1742-7061}}</ref> The dura mater is itself a two layered membrane: an outer [[endosteal]] (periosteal) layer lies closest to the skull, and an inner (meningeal or dura mater proper) layer lies closer to the brain.<ref name="Suh">{{cite journal |last1=Suh |first1=DC |title=Where Did the Dura Mater Come from? |journal=Neurointervention |date=March 2020 |volume=15 |issue=1 |pages=2–3 |doi=10.5469/neuroint.2020.00045 |pmid=32093449 |pmc=7105093 }}</ref><ref name="Levy" /> These layers separate to surround the dural venous sinuses. Sensory and autonomic nerves innervate the dura, and are dense near its blood vessels.<ref name="Levy" /> The dura's inner surface is covered by flattened fibrocytes which are adhered to by the outer cells of the arachnoid mater.<ref>{{Cite book |last1=Figueiredo |first1=Marxa L. |url=https://books.google.com/books?id=7gVVEQAAQBAJ&dq=inner+surface+of+the+dura+mater+inner+surface+is+covered+by+flattened+cells&pg=PA99 |title=Dellmann's Textbook of Veterinary Histology |last2=Turek |first2=John J. |date=2025-04-09 |publisher=John Wiley & Sons |isbn=978-1-394-19670-8 |language=en}}</ref> The dura mater surrounds the arachnoid mater and supports the [[dural sinuses]] which carry blood from the brain to the heart.<ref name="Dasgupta">{{cite journal |last1=Dasgupta |first1=K |last2=Jeong |first2=J |title=Developmental biology of the meninges. |journal=Genesis |date=2019 |volume=57 |issue=5 |article-number=e23288 |doi=10.1002/dvg.23288 |pmid=30801905 |pmc=6520190 }}</ref>

The dura mater folds inwards upon itself to form four areas of infolding called dural reflections:<ref name=":0">{{Cite book |last1=Agur |first1=Anne M. R. |url=https://books.google.com/books?id=HJWkEAAAQBAJ&dq=dura+has+four+areas+of+infolding:+Falx++cerebri+-StatPearls&pg=PT1071 |title=Moore's Essential Clinical Anatomy |last2=Dalley |first2=Arthur F. |date=2022-12-29 |publisher=Lippincott Williams & Wilkins |isbn=978-1-9751-7425-5 |language=en}}</ref><ref>{{Cite book |last=Andreatta |first=Richard D. |url=https://books.google.com/books?id=XfqUEAAAQBAJ&dq=arachnoid+loosley+fitting+sac&pg=PA259 |title=Neuroscience Fundamentals for Communication Sciences and Disorders, Second Edition |date=2022-10-13 |publisher=Plural Publishing |isbn=978-1-63550-360-9 |language=en}}</ref>
* [[Falx cerebri]]: This sickle-shaped fold is the largest of the dural reflections.  It separates the two [[cerebral hemisphere]]s, and is anchored to the [[crista galli]] of the [[ethmoid bone]] and the [[internal occipital protuberance]].<ref name=":0" />
* [[Tentorium cerebelli]]. The second largest fold is also crescent-shaped. It separates the [[occipital lobe]]s of the [[cerebrum]] from the [[cerebellum]]. The falx cerebri attaches to it to form the roof of the [[posterior cranial fossa]], which gives it a tentlike appearance.<ref name=":0" /><ref>{{cite journal |last1=Rai |first1=R |last2=Iwanaga |first2=J |last3=Shokouhi |first3=G |last4=Oskouian |first4=RJ |last5=Tubbs |first5=RS |title=The Tentorium Cerebelli: A Comprehensive Review Including Its Anatomy, Embryology, and Surgical Techniques. |journal=Cureus |date=31 July 2018 |volume=10 |issue=7 |article-number=e3079 |doi=10.7759/cureus.3079 |doi-access=free |pmid=30305987 |pmc=6168052 }}</ref>
* [[Falx cerebelli]]: This vertical infolding is located inferior to the tentorium cerebelli. It <mark>partially separates the</mark> [[cerebellar hemisphere|<mark>cerebellar hemispheres</mark>]].<ref name=":0" />
* [[Diaphragma sellae]]: The smallest of the infoldings, it forms a roof over the   [[sella turcica]] and seals the [[pituitary gland]] from the subarachnoid space.<ref name=":0" /><ref>{{cite journal |last1=Rasmussen |first1=MK |last2=Mestre |first2=H |last3=Nedergaard |first3=M |title=Fluid transport in the brain. |journal=Physiological Reviews |date=1 April 2022 |volume=102 |issue=2 |pages=1025–1151 |doi=10.1152/physrev.00031.2020 |pmid=33949874 |pmc=8897154 }}</ref>
[[File:Brain layers.jpg|thumb|Diagram of brain layers]]

===Arachnoid mater===
{{Main|Arachnoid mater}}

[[File: 1316 Meningeal LayersN.jpg|thumb|upright=1.6|Diagram of section of top of brain showing the meninges and subarachnoid space]]
The [[arachnoid mater]], or arachnoid membrane, is the middle element of the meninges. Thin and transparent, its name reflects its resemblance to a [[spider web]]. Its fibrous tissue cushions the [[central nervous system]].  Like the pia mater, it has an outer layer of tightly packed flat cells, forming the arachnoid barrier.<ref name="Abbott">{{cite journal |last1=Abbott |first1=NJ |last2=Patabendige |first2=AA |last3=Dolman |first3=DE |last4=Yusof |first4=SR |last5=Begley |first5=DJ |title=Structure and function of the blood-brain barrier. |journal=Neurobiology of Disease |date=January 2010 |volume=37 |issue=1 |pages=13–25 |doi=10.1016/j.nbd.2009.07.030 |pmid=19664713|s2cid=14753395 }}</ref>

The arachnoid is loosely fitting and does not closely follow the <mark>ridges</mark> <mark>and grooves on</mark> the surface of the brain. A large number of fine filaments called [[arachnoid trabeculae]] pass from the arachnoid through the subarachnoid space to blend with the tissue of the pia mater.<ref>{{cite book |last1=Schröder |first1=Hannsjörg |last2=Vos |first2=Rob A. I. de |last3=Huggenberger |first3=Stefan |last4=Müller-Thomsen |first4=Lennart |last5=Rozemuller |first5=Annemieke |last6=Hedayat |first6=Farman |last7=Moser |first7=Natasha |title=The Human Brainstem: Anatomy and Pathology |date=8 August 2023 |publisher=Springer Nature |isbn=978-3-030-89980-6 |page=71 |url=https://books.google.com/books?id=fBfQEAAAQBAJ&dq=arachnoid+trabeculae+pass+from+the+arachnoid+through+the+subarachnoid+space+to+blend+with+the+tissue+of+the+pia+mater.&pg=PA71 |language=en}}</ref> The arachnoid barrier creates a restrictive permeability barrier between the cerebrospinal fluid in the subarachnoid space and the blood circulation in the dura.<ref name="Betsholtz" />

The arachnoid barrier layer is characterized by a distinct continuous basal lamina on its inner surface toward the innermost collagenous portion of the arachnoid reticular layer.<ref>{{cite journal |last1=Izadi |first1=N |last2=Solár |first2=P |last3=Hašanová |first3=K |last4=Zamani |first4=A |last5=Akbar |first5=MS |last6=Mrázová |first6=K |last7=Bartošík |first7=M |last8=Kazda |first8=T |last9=Hrstka |first9=R |last10=Joukal |first10=M |title=Breaking boundaries: role of the brain barriers in metastatic process. |journal=Fluids and Barriers of the CNS |date=8 January 2025 |volume=22 |issue=1 |page=3 |doi=10.1186/s12987-025-00618-z |doi-access=free |pmid=39780275 |pmc=11708195 |issn=2045-8118}}</ref>

===Pia mater===
{{Main|Pia mater}}

The pia mater ({{langx|la|tender mother|links=no}})<ref name="merriam-webster.com_pia_mater">{{cite dictionary|url=https://www.merriam-webster.com/dictionary/pia+mater|title=Definition of pia mater|dictionary=[[Merriam-Webster]] Online Dictionary|access-date=27 November 2015}}</ref> is a very delicate membrane. It is the meningeal envelope that firmly adheres to the surfaces of the brain and spinal cord,<ref name="Levy" /> following all of the brain's contours ([[gyrus|gyri]] and [[sulcus (neuroanatomy)|sulci]]).<ref>{{Cite book |last1=Barichello |first1=Tatiana |url=https://books.google.com/books?id=PE7VEAAAQBAJ&dq=gyri+pia+mater&pg=PA13 |title=Neurobiology of Infectious Diseases |last2=Dal-Pizzol |first2=Felipe |last3=Hasbun |first3=Rodrigo |date=2024-11-30 |publisher=Elsevier |isbn=978-0-443-19131-2 |page=13 |language=en}}</ref> It is a very thin sheet of connective tissue that interfaces with the glial limitans superficialis but lacks capillaries itself.<ref name="Levy" />

=== Subarachnoidal lymphatic-like membrane ===
{{Excerpt|subarachnoidal lymphatic-like membrane}}

===Leptomeninges===
The [[arachnoid (brain)|arachnoid]] and [[pia mater]] are sometimes together called the ''leptomeninges'',<ref>{{cite web|title=leptomeninges |url=https://en.oxforddictionaries.com/definition/leptomeninges|archive-url=https://web.archive.org/web/20161104012057/https://en.oxforddictionaries.com/definition/leptomeninges|archive-date=November 4, 2016|website=Oxford Dictionaries {{!}} English}}</ref> literally "thin meninges" ({{langx|el|λεπτός}} "leptos"—"thin"). Acute [[meningococcal meningitis]] can lead to an [[exudate]] within the  leptomeninges along the surface of the brain.<ref>{{Cite book |last=Kumar |first=Vinay |year=2015 |title=Robbins and Cotran Pathologic Mechanisms of Disease |location=Philadelphia |publisher=Elsevier Saunders |edition=9th |page=1273 |oclc=892583347 |quote=In acute meningitis, an exudate is evident within the leptomeninges over the surface of the brain (Fig. 28-21).}}</ref> Because the arachnoid is connected to the pia by cobweb-like strands, it is structurally continuous with the pia, hence the name pia-arachnoid or leptomeninges. They are responsible for the production of beta-trace protein ([[prostaglandin D2 synthase]]), a major cerebrospinal fluid protein.<ref name=":1">{{cite journal |last1=Yamashima |first1=Tetsumori |last2=Sakuda |first2=Kazushige |last3=Tohma |first3=Yasuo |last4=Yamashita |first4=Junkoh |last5=Oda |first5=Hiroshi |last6=Irikura |first6=Daisuke |last7=Eguchi |first7=Naomi |last8=Beuckmann |first8=Carsten T. |last9=Kanaoka |first9=Yoshihide |last10=Urade |first10=Yoshihiro |last11=Hayaishi |first11=Osamu |title=Prostaglandin D Synthase (β-Trace) in Human Arachnoid and Meningioma Cells: Roles as a Cell Marker or in Cerebrospinal Fluid Absorption, Tumorigenesis, and Calcification Process |url= |journal=Journal of Neuroscience |pages=2376–2382 |language=en |date=1 April 1997 |volume=17 |issue=7 |doi=10.1523/JNEUROSCI.17-07-02376.1997|pmid=9065498 |pmc=6573504 |s2cid=15404074 }}</ref>

===Subarachnoid space===
[[File: Gray770-en.svg|thumb|Diagram of section of spinal cord showing the meninges and spaces. Subarachnoid space coloured blue]]
The '''subarachnoid space''' is the space that normally exists between the [[arachnoid (brain)|arachnoid]] and the [[pia mater]]. It is filled with [[cerebrospinal fluid]] and continues down the [[spinal cord]]. Spaces are formed from openings at different points along the subarachnoid space; these
are the [[subarachnoid cisterns]], which are filled with cerebrospinal fluid.<ref name="Hladky">{{cite journal |last1=Hladky |first1=SB |last2=Barrand |first2=MA |title=Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus. |journal=Fluids and Barriers of the CNS |date=17 July 2024 |volume=21 |issue=1 |page=57 |doi=10.1186/s12987-024-00532-w |doi-access=free |pmid=39020364 |pmc=11253534 }}</ref>

The dura mater is attached to the [[Human skull|skull]],<ref name="Suh" /> whereas in the spinal cord, the dura mater is separated from the [[vertebra]]e by a space called the [[epidural space]], which contains fat and blood vessels. The arachnoid is attached to the dura mater, while the pia mater is attached to the central nervous system tissue. If the dura mater and the arachnoid become separated due to injury or illness, the space between them is known as the '''[[subdural space]]'''.<ref>{{cite book |last1=Carstens |first1=Michael H. |title=The Embryologic Basis of Craniofacial Structure: Developmental Anatomy, Evolutionary Design, and Clinical Applications |date=27 September 2023 |publisher=Springer Nature |isbn=978-3-031-15636-6 |page=1040 |url=https://books.google.com/books?id=w_XZEAAAQBAJ&dq=meninges+Giuseppe+Sterzi&pg=PA1040 |language=en}}</ref><ref>{{cite journal |last1=Macpherson |first1=D |last2=Quondamatteo |first2=F |last3=Broom |first3=M |title=Update on applied epidural anatomy. |journal=BJA Education |date=May 2022 |volume=22 |issue=5 |pages=182–189 |doi=10.1016/j.bjae.2021.12.006 |pmid=35496647 |pmc=9039569 }}</ref> There is another potential space, the '''subpial space''', between the pia mater and the [[glia limitans]].<ref>{{cite journal |last1=Server |first1=A |last2=Latysheva |first2=A |last3=Nedregaard |first3=B |last4=Rønnestad |first4=AE |last5=Marthinsen |first5=PB |title=Neonatal subpial hemorrhage: clinical presentation, neuroimaging findings and outcome. |journal=Neuroradiology |date=April 2025 |volume=67 |issue=4 |pages=1071–1080 |doi=10.1007/s00234-025-03589-y |pmid=40095005 |pmc=12041188 }}</ref>

==Clinical significance==
Three types of [[intracranial hemorrhage]] can involve the meninges: epidural, subdural, and subarachnoid.<ref name="Parizel"/>

* A [[subarachnoid hemorrhage]] is acute bleeding under the arachnoid; it may occur spontaneously or as a result of trauma.<ref>{{cite journal |vauthors=van Gijn J, Kerr RS, Rinkel GJ |title=Subarachnoid haemorrhage |journal=Lancet |volume=369 |issue=9558 |pages=306–18 |year=2007 |pmid=17258671 |doi=10.1016/S0140-6736(07)60153-6|s2cid=29126514 }}</ref><ref name="Parizel">{{cite book |last1=Parizel |first1=Paul M. |last2=Philips |first2=C. Douglas |title=Diseases of the Brain, Head and Neck, Spine 2020–2023 |date=2020 |publisher=Springer International Publishing |isbn=978-3-030-38489-0 |pages=77–92 |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK554351/ |language=en |chapter=Traumatic Neuroemergency: Imaging Patients with Traumatic Brain Injury—An Introduction |doi=10.1007/978-3-030-38490-6_7 |pmid=32119255 }}</ref>
* A [[subdural hematoma]] (SDH) is an extracerebral collection of blood located in the potential space that can separate [[arachnoid (brain)|arachnoid]] from the dura mater.  The origin is usually venous, caused by injury to the [[bridging vein]]s that connect the dura mater and the [[arachnoid (brain)|arachnoid]]. Once these are torn, blood leaks into this area. SDHs occur in about 30% cases of severe head trauma.<ref name="Parizel"/>
* An [[epidural hematoma]] (EDH) is a collection of blood between the [[skull]] and the dura mater, underlying a bare bone surface. It is often associated with skull fracture. EDH may be arterial (caused by injury of a meningeal artery) or venous (related to damage to of a dural venous sinus or bleeding from diploic veins).<ref name="Parizel"/>

Other medical conditions that affect the meninges include [[meningitis]], which usually arises from a [[virus|viral]], [[bacterial]], or  [[fungal]] [[infection]].<ref>{{cite journal |last1=Garber |first1=B |last2=Glauser |first2=J |title=Viral Meningitis and Encephalitis Update |journal=Current Emergency and Hospital Medicine Reports |date=1 September 2024 |volume=12 |issue=3 |pages=95–102 |doi=10.1007/s40138-024-00294-7 |language=en |issn=2167-4884|doi-access=free }}</ref><ref>{{cite journal |last1=Gundamraj |first1=V |last2=Hasbun |first2=R |title=Viral meningitis and encephalitis: an update. |journal=Current Opinion in Infectious Diseases |date=1 June 2023 |volume=36 |issue=3 |pages=177–185 |doi=10.1097/QCO.0000000000000922 |pmid=37093042}}</ref>

[[Meningioma]]s are the most common type of primary [[brain tumors]] to occur in adults. They are thought to arise from meningothelial arachnoid cells in the meninges. Most commonly they attach firmly to the inner surface of the dura and are well-circumscribed; but some [[tumors]] may show brain invasion.<ref>{{cite journal |last1=Szulzewsky |first1=F |last2=Thirimanne |first2=HN |last3=Holland |first3=EC |title=Meningioma: current updates on genetics, classification, and mouse modeling. |journal=Upsala Journal of Medical Sciences |date=2024 |volume=129 |article-number=e10579 |doi=10.48101/ujms.v129.10579 |pmid=38571886 |pmc=10989216 }}</ref> More rarely, [[leptomeningeal cancer]]s may [[metastasis|metastasize]] from tumors elsewhere in the body to the cerebrospinal fluid and leptomeninges.<ref>{{cite journal |last1=Nguyen |first1=A |last2=Nguyen |first2=A |last3=Dada |first3=OT |last4=Desai |first4=PD |last5=Ricci |first5=JC |last6=Godbole |first6=NB |last7=Pierre |first7=K |last8=Lucke-Wold |first8=B |title=Leptomeningeal Metastasis: A Review of the Pathophysiology, Diagnostic Methodology, and Therapeutic Landscape. |journal=Current Oncology (Toronto, Ont.) |date=19 June 2023 |volume=30 |issue=6 |pages=5906–5931 |doi=10.3390/curroncol30060442 |doi-access=free |pmid=37366925 |pmc=10297027 }}</ref>

According to preliminary research, migraine may be linked to the meninges through the activity of [[Calcitonin gene-related peptide receptor antagonist|calcitonin gene-related peptide]] (CGRP) released from the axonal endings of the trigeminal nerve that project from the central nervous system.<ref name="Levy">{{cite journal |last1=Levy |first1=D |last2=Moskowitz |first2=MA |title=Meningeal Mechanisms and the Migraine Connection|journal=Annual Review of Neuroscience |date=10 July 2023 |volume=46 |pages=39–58 |doi=10.1146/annurev-neuro-080422-105509 |pmid=36913712 |pmc=11412714 |issn=0147-006X}}</ref> Stimulation of the trigeminal nerve may result in release of [[neuropeptides]] such as CGRP, [[vasodilation]] of cerebral and dural blood vessels, [[neurogenic inflammation]], and the transmission of [[Nociception|pain signals]] via nerves in the meninges.<ref name=Levy/>

==Other animals==
In [[fish]], there is a single membrane known as the primitive meninx.<ref name="Ostrander">{{cite book |last1=Ostrander |first1=Gary |title=The Laboratory Fish |url=https://books.google.com/books?id=Hp4YSFiSD0IC&q=fish+meninges&pg=PT135 |publisher=Elsevier |language=en |date=12 September 2000|isbn=978-0-12-529650-2 }}</ref> [[Amphibian]]s and [[reptile]]s have two meninges, and [[bird]]s and mammals have three.<ref name="Ostrander"/> 
[[Mammal]]s (as higher vertebrates) retain the dura mater, and the secondary meninx divides into the [[arachnoid mater|arachnoid]] and [[pia mater]].<ref>{{cite book |last=Kardong |first=Kenneth V. |year=1995 |title=Vertebrates: Comparative Anatomy, Function, Evolution |location=Dubuque, Iowa |publisher=Wm. C. Brown Publishers. |page=539 |isbn=0-697-21991-7}}</ref>

==History==
The first known reference to the dura appears in Egypt, in Case 6 of the [[Edwin Smith Papyrus]]. [[Hippocrates]] described the dura in his monograph "On Injuries of the Head" and insisted that care should be taken to keep it intact and clean.<ref name="Ganz">{{cite book |last1=Ganz |first1=JC |title=The meninges. |series=Progress in Brain Research |date=2024 |volume=285 |pages=137–147 |doi=10.1016/bs.pbr.2024.02.020 |pmid=38705713 |isbn=978-0-443-31718-7 }}</ref> [[Celsus]] agreed, and described a method of treatment for depressed fractures.<ref>{{cite journal |last1=Talamonti |first1=G |last2=D'Aliberti |first2=G |last3=Cenzato |first3=M |title=Aulus Cornelius Celsus and the Head Injuries. |journal=World Neurosurgery |date=January 2020 |volume=133 |pages=127–134 |doi=10.1016/j.wneu.2019.09.119 |pmid=31568909}}</ref> [[Galen]] was the first to describe the pia mater in humans in the second century AD.<ref name="Lu"/>

[[File:Acta Eruditorum - IV fisiologia, 1703 – BEIC 13363829.jpg|thumb|right|300px|Illustration by [[Antonio Pacchioni]], ''[[Acta Eruditorum]]'', 1703]]
The arachnoid layer was first described by Dutch physician [[Gerard Blasius|Gerardus Blasius]] in 1664.<ref name="Lu">{{cite journal |last1=Lu |first1=S |last2=Brusic |first2=A |last3=Gaillard |first3=F |title=Arachnoid Membranes: Crawling Back into Radiologic Consciousness. |journal=AJNR. American Journal of Neuroradiology |date=February 2022 |volume=43 |issue=2 |pages=167–175 |doi=10.3174/ajnr.A7309 |pmid=34711549|pmc=8985673 }}</ref>
In 1695, [[Humphrey Ridley]] first described the subarachnoid cisterns. He also contributed to the understanding of the blood-brain barrier, and accurately described the fifth cranial nerve ganglion with its branches.<ref>{{cite journal |last1=Thakur |first1=JD |last2=Sonig |first2=A |last3=Chittiboina |first3=P |last4=Khan |first4=IS |last5=Wadhwa |first5=R |last6=Nanda |first6=A |title=Humphrey Ridley (1653-1708): 17th century evolution in neuroanatomy and selective cerebrovascular injections for cadaver dissection. |journal=Neurosurgical Focus |date=August 2012 |volume=33 |issue=2 |pages=E3 |doi=10.3171/2012.6.FOCUS12139 |pmid=22853834}}</ref>  In 1699, [[Frederik Ruysch|Frederick Ruysch]] confirmed that the arachnoid mater formed a complete layer that surrounded the brain. Its current name is based on his description of its spiderlike morphology.<ref>{{Cite journal |last1=Mortazavi |first1=Martin M. |last2=Quadri |first2=Syed A. |last3=Khan |first3=Muhammad A. |last4=Gustin |first4=Aaron |last5=Suriya |first5=Sajid S. |last6=Hassanzadeh |first6=Tania |last7=Fahimdanesh |first7=Kian M. |last8=Adl |first8=Farzad H. |last9=Fard |first9=Salman A. |last10=Taqi |first10=M. Asif |last11=Armstrong |first11=Ian |last12=Martin |first12=Bryn A. |last13=Tubbs |first13=R. Shane |date=2018-03-01 |title=Subarachnoid Trabeculae: A Comprehensive Review of Their Embryology, Histology, Morphology, and Surgical Significance |url=https://www.sciencedirect.com/science/article/pii/S1878875017321575 |journal=World Neurosurgery |volume=111 |pages=279–290 |doi=10.1016/j.wneu.2017.12.041 |issn=1878-8750|url-access=subscription }}</ref> Arachnoid granulations were first described by Italian physician [[Antonio Pacchioni]] who published his ''Dissertatio Epistolaris de Glandulis Conglobatis Durae Meningis Humanae'' in 1705.<ref>{{cite journal |last1=Artico |first1=M |last2=Galassi |first2=FM |last3=Carubbi |first3=C |last4=Vitale |first4=M |last5=Cofone |first5=L |title=Antonio Pacchioni: italian physician and anatomist |journal=The Lancet Neurology |date=1 July 2025 |volume=24 |issue=7 |page=567 |doi=10.1016/S1474-4422(25)00200-5 |url=https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(25)00200-5/abstract?rss=yes |language=English |issn=1474-4422|url-access=subscription }}</ref>

In seven articles from 1899 to 1902, Italian anatomist [[Giuseppe Sterzi]] described comparative studies on the meninges from the [[lancelet]] to the human. He showed that the spinal meninges were very simple in adult lower vertebrates and in the early development of more advanced vertebrates.<ref>{{cite journal |last1=Riva |first1=Alessandro |last2=Orrù |first2=Beniamino |last3=Riva |first3=Francesca Testa |title=Giuseppe Sterzi (1876–1919) of the University of Cagliari: A brilliant neuroanatomist and medical historian |journal=The Anatomical Record |date=2000 |volume=261 |issue=3 |pages=105–110 |doi=10.1002/1097-0185(20000615)261:3<105::AID-AR5>3.0.CO;2-H |pmid=10867628 |url=https://anatomypubs.onlinelibrary.wiley.com/doi/full/10.1002/1097-0185%2820000615%29261%3A3%3C105%3A%3AAID-AR5%3E3.0.CO%3B2-H |language=en |issn=1097-0185}}</ref>

==See also==
* [[Cranial cavity]]

==Notes==
{{Notelist}}

==References==
{{Reflist|2}}

== External links ==
* {{Commons category-inline |Meninges}}

{{Nervous system}}
{{Meninges}}
{{Spinal cord}}
{{Authority control}}

[[Category:Meninges| ]]
[[Category:Back anatomy]]
[[Category:Human head and neck]]