Cranial meninges Flashcards
What are the three layers of cranial meninges (outer to inner)?
dura mater, arachnoid mater, pia mater
Dura mater
consists of an outer periosteal layer and an inner meningeal layer
Diaphragmatic sellae
a sheet of dura mater which attaches to the clinoid process of the sphenoid bone- it covers the pituitary gland and contains an opening through which the infundibulum and hypophysial veins pass
Extradural space
A pathological space that forms when blood leaks from torn meningeal vessels and pushes the periosteum away from the cranium
Arachnoid mater
thin, avascular membrane composed of fibroblasts, collagen fibres and some elastic fibres- it is pushed up against the inner surface of the dura mater by the pressure of cerebrospinal fluid
subarachnoid space
lies between the arachnoid mater and the pia mater- it contains CSF, arteries and veins
Pia mater
A very thin, highly vascularised membrane
Falx cerebri
an infolding of meningeal dura mater located in the longitudinal fissure- attaches to the median plane of the calvarium from the frontal crest of the fronta bone and crista galli of the ethmoid bone anteriorly to the internal occipital protuberance posteriorly
Falx cerebelli
A dural reflection that attaches to the internal occipital crest, it partially separates the cerebellar hemispheres
tentorium cerebelli
dural reflection which separates the occipital lobes from the cerebellum- it attaches to the clinoid process of the sphenoid bone, petrous temporal bone, internal surface of the occipital bone and part of the parietal bone
Which artery does the dura mater receive most of its arterial blood from?
The middle meningeal artery
Middle meningeal artery: where and which artery does it arise from, where does it enter the skull and where does it lie in the cranium?
1- arises from the maxillary artery in the infratemporal fossa
2-enters into the middle cranial fossa via the foramen spinosum- bifurcates into frontal and parietal branches
3- lies between the meningeal and periosteal layers of the dura mater
Where do the middle meningeal veins leave the skull and drain into?
Leave via the foramen spinosum and drain into the pterygoid plexus
Why is the frontal branch of the middle meningeal artery at risk of trauma to the lateral side of head?
it crosses the pterion- this is the thinnest part of the skull where the frontal, parietal, sphenoid and temporal bones meet
What is the dura mater innervated by?
branches of the vagus, trigeminal and first 3 cervical nerves
