Middle meningeal artery 1017724 219631287 2008-06-16T04:17:12Z Psanders77 7317028 {{Infobox Artery | Name = {{PAGENAME}} | Latin = arteria meningea media | GraySubject = 144 | GrayPage = 560 | Image = Gray511.png | Caption = Plan of branches of internal [[maxillary artery]]. (middle meningeal visible top left) | Image2 = Gray1198.png | Caption2 = Relations of the brain and middle meningeal artery to the surface of the skull. | BranchFrom = [[internal maxillary artery]] | BranchTo = anterior: posterior: [[superior tympanic artery]] | Vein = [[middle meningeal vein]] | Supplies = [[meninges]] | MeshName = | MeshNumber = | DorlandsPre = a_61 | DorlandsSuf = 12155038 | }} The '''middle meningeal artery''' ([[Latin language|Latin]] ''arteria meningea media'') is typically the third branch of the first part (retromandibular part) of the [[maxillary artery]]; one of the two terminal branches of the [[external carotid artery]]. After branching off the maxillary artery in the infratemporal fossa, it runs through the [[foramen spinosum]] to supply the [[dura mater]] (the outermost [[meninges]]) and the [[calvaria]]. The middle meningeal artery is the largest of the three (paired) arteries which supply the meninges, the others being the [[anterior meningeal artery]] and the [[posterior meningeal artery]]. In approximately half of subjects it branches into an [[accessory meningeal artery]]. The middle meningeal artery runs beneath the [[pterion]]. It is vulnerable to injury at this point, where the skull is thin. Rupture of the artery may give rise to an [[epidural hematoma]]. ==Branches== ===Before entering cranium=== It ascends between the [[sphenomandibular ligament]] and the [[Pterygoideus externus]], and between the two roots of the [[auriculotemporal nerve]] to the [[foramen spinosum]] of the [[sphenoid bone]], through which it enters the [[cranium]]; it then runs forward in a groove on the great wing of the [[sphenoid bone]], and divides into two branches, anterior and posterior. The ''anterior branch'', the larger, crosses the great wing of the sphenoid, reaches the groove, or canal, in the sphenoidal angle of the [[parietal bone]], and then divides into branches which spread out between the dura mater and internal surface of the cranium, some passing upward as far as the [[vertex (anatomy)|vertex]], and others backward to the [[occipital]] region. The ''posterior branch'' curves backward on the [[squama temporalis|squamous part]] of the [[temporal bone]], and, reaching the parietal bone some distance in front of its mastoid angle, divides into branches which supply the posterior part of the dura mater and cranium. The branches of the middle meningeal artery are distributed partly to the dura mater, but chiefly to the bones; they anastomose with the arteries of the opposite side, and with the [[anterior meningeal arteries|anterior]] and [[posterior meningeal arteries]]. The very smallest distal branches [[anastomosis|anastomose]] through the [[skull]] with small arterioles from the [[scalp]]. Very rarely the [[ophthalmic artery]] may arise as a branch of the middle meningeal artery. ===Branches upon entering cranium=== On entering the cranium, the middle meningeal artery gives off the following branches: * (1) Numerous small vessels supply the [[semilunar ganglion]] and the [[dura mater]] in this situation. * (2) A superficial petrosal branch enters the [[hiatus of the facial canal]], supplies the [[facial nerve]], and anastomoses with the [[stylomastoid branch]] of the [[posterior auricular artery]]. * (3) A [[superior tympanic artery]] runs in the canal of the [[tensor tympani]] muscle, and supplies this muscle and the lining of the canal. * (4) Orbital branches pass through the [[superior orbital fissure ]]or through separate canals in the [[great wing of the sphenoid]], to anastomose with the [[Lacrimal artery|lacrimal]] or other branches of the [[ophthalmic artery]]. * (5) Temporal branches pass through foramina in the [[great wing of the sphenoid]], and anastomose in the [[temporal fossa]] with the [[deep temporal arteries]]. ==Clinical relevance== An injured middle meningeal artery is the cause of an [[epidural hematoma]]. A head injury (e.g. from a [[road traffic accident]] or [[sports injury]]) is required to rupture the artery. Emergency treatment requires decompression of the haematoma, usually by [[craniotomy]]. [[Subdural hematoma|Subdural bleeding]] is usually ''venous'' in nature, rather than arterial. The middle meningeal artery runs in a groove on the inside of the [[cranium]]. This can clearly be seen on a lateral skull [[X-ray]], where it may be mistaken for a fracture of the skull. On a dry specimen the groove is easy to see. This means that the artery is easy to study, even in specimens centuries old, and several classifications of the branches have been proposed, e.g. Adachi's classification of 1928. ==Additional images== <gallery> Image:Gray133.png|Left parietal bone. Inner surface. Image:Gray138.png|Left temporal bone. Inner surface. Image:Gray193.png|Base of the skull. Upper surface. Image:Gray778.png|Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion. Image:Gray783.png|The otic ganglion and its branches. Image:Gray789.png|The course and connections of the facial nerve in the temporal bone. Image:Human brain dura mater description.JPG|Human brain dura mater </gallery> ==External links== * {{SUNYAnatomy|27|04|03}} * {{NormanAnatomy|lesson4}} ({{NormanAnatomyFig|infratempfossaart}}) * [http://bubbasoft.org/carotid_collaterals/anterior_falx_artery.htm Photos with captions at bubbasoft.org] {{Gray's}} {{Arteries of head and neck}} [[Category:Arteries]] [[de:Arteria meningea media]] [[la:Arteria meningea media]]