{{Infobox Anatomy |
  Name         =  |
  Latin        = |
  GraySubject  = 193 |
  GrayPage     = 872 |
  Image        = Illu meninges.jpg |
  Caption      = Meninges of the CNS | 
  Image2       = |
  Caption2     = |
  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        = |
  MeshName     = Meninges |
  MeshNumber   = A08.186.566 |
  DorlandsPre  = m_09 |
  DorlandsSuf  = 12523818  |
}}
The '''meninges''' (singular '''meninx''') is the system of membranes which envelops the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.

==Anatomy==

===Pia mater===
The pia or '''gyri and sulci). The pia mater is the meningeal envelope which firmly adheres to the surface of the brain and spinal cord. It is a very thin membrane composed of fibrous tissue covered on its outer surface by a sheet of flat cells thought to be impermeable to fluid. The pia mater is pierced by blood vessels which travel to the brain and spinal cord, and its capillaries are responsible for nourishing the brain.

===Arachnoid mater===
The middle element of the meninges is the '''arachnoid mater''', so named because of its spider web-like appearance. It provides a cushioning effect for the central nervous system. The arachnoid mater exists as a thin, transparent membrane. It is composed of fibrous tissue and, like the pia mater, is covered by flat cells also thought to be impermeable to fluid. The arachnoid does not follow the convolutions of the surface of the brain and so looks like a loosely fitting sac. In the region of the brain, particularly, 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.

The arachnoid and pia mater are sometimes together called the ''leptomeninges''.

===Dura mater===
The '''dura mater''' (also rarely called meninx fibrosa, or pachymeninx) is a thick, durable membrane, closest to the skull. It consists of two layers, the periosteal layer, closest to the calvaria and the inner meningeal layer. It contains larger blood vessels which split into the capilliaries in the pia mater. It is composed of dense fibrous tissue, and its inner surface is covered by flattened cells like those present on the surfaces of the pia mater and arachnoid. The dura mater is a sac which envelops the arachnoid and has been modified to serve several functions. The dura mater surrounds and supports the large venous channels (dural sinuses) carrying blood from the brain toward the heart.

===Spaces===
The arachnoid and the pia mater, which is filled with cerebrospinal fluid.

Normally, the arachnoid is attached to the arachnoid separate through injury or illness, the space between them is the subdural space. 

thumb|300px|[[Hjernen er omsluttet av hjernehinnene pia mater, arachnoidea og dura mater. På figuren ses disse avbildet (tysk)]]
'''Hjernehinnene''' er et hinnesystem som omslutter hjernen. Det består av tre lag: dura mater, arachnoidea, og pia mater. 

* Pia mater er en svært ømfintlig hinne. Den ligger nærmest hjernen og går helt inn i de dypeste furene mellom hjernevindingene. 
* Den midtre hjernehinnen er arachnoidea. Dette er en tynn hinne med tynne festetråder til nervevevet, som har fått navnet fordi det ligner på et spindelvev.
* Helt ytterst mot hodeskallen ligger dura mater, også kjent som årehinne, den er en tykk og hard bindevevshinne.

Subarachnoidealrommet er mellomrommet som normalt finnes mellom arachnoidea og pia mater. Rommet består av cerebrospinalvæske og bindevev formet som et nettverk. 

Dura mater er vanligvis festet til kraniet, spindelvevshinnen (arachnoidae) er festet til dura mater, og pia mater er festet til hjernen. Når dura mater og spindelvevshinnen separeres ved skade eller sykdom, dannes et rom mellom som kalles subduralt rom (subdural space).