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The dura mater (or just dura) is the outermost of the three meninges. The dura mater has two layers, an outer Periosteum closely adhered to the neurocranium, and an inner meningeal layer known as the dural border cell layer. The two dural layers are for the most part fused together forming a thick fibrous tissue membrane that covers the brain and the of the spinal column. (2025). 9781264930395, McGraw Hill. ISBN 9781264930395 But the layers are separated at the dural venous sinuses to allow blood to drain from the brain. The dura covers the arachnoid mater and the pia mater, the other two meninges, in protecting the central nervous system.
At major boundaries of brain regions such as the longitudinal fissure between the hemispheres, and the tentorium cerebelli between the posterior brain and the cerebellum the dura separates, folds and invaginates to make the divisions. These folds are known as dural folds, or reflections.
The dura mater is primarily derived from neural crest cells, with postnatal contributions from the paraxial mesoderm.
Cranial dura mater has two layers which include a superficial periosteal layer that is actually the inner periosteum of the neurocranium (the calvarium and endocranium); and a deep meningeal layer, which is the true dura mater. The dura mater covering the spinal cord is known as the dural sac or thecal sac, and only has one layer (the meningeal layer) unlike cranial dura mater. The potential space between these two layers is known as the epidural space, University of New England, The Dura Mater. which can accumulate blood in the case of traumatic laceration to the meningeal arteries.
Two other dural infoldings are the cerebellar falx and the sellar diaphragm:
A. posterior meningeal artery (from the ascending pharyngeal artery through the jugular foramen)
B. meningeal arteries (from the ascending pharyngeal artery through hypoglossal canal)
C. meningeal arteries (from occipital artery through jugular or mastoid foramen)
D. meningeal arteries (from vertebral artery through foramen magnum)
Arachnoid villi, which are outgrowths of the arachnoid mater (the middle meningeal layer), extend into the dural venous sinuses to drain CSF. These villi act as one-way valves. Meningeal veins, which course through the dura mater, and , which drain the underlying neural tissue and puncture the dura mater, empty into these dural sinuses. A rupture of a bridging vein causes a subdural hematoma.
In 2011, researchers discovered a connective tissue bridge from the rectus capitis posterior major to the cervical dura mater. Various clinical manifestations may be linked to this anatomical relationship such as headaches, trigeminal neuralgia and other symptoms that involved the cervical dura. The rectus capitis posterior minor has a similar attachment.
The dura-muscular, dura-ligamentous connections in the upper cervical spine and occipital areas may provide anatomic and physiologic answers to the cause of the cervicogenic headache. This proposal would further explain manipulation's efficacy in the treatment of cervicogenic headache.
The American Red Cross and some other agencies accepting blood donations consider dura mater transplants, along with receipt of pituitary-derived growth hormone, a risk factor due to concerns about Creutzfeldt–Jakob disease.International Red Cross and Red Crescent Movement - redcross.org
Cerebellar tonsillar ectopia, or Chiari malformation, is a condition that was previously thought to be congenital but can be induced by trauma, particularly whiplash trauma. Dural strain may be pulling the cerebellum inferiorly, or skull distortions may be pushing the brain inferiorly.
Dural ectasia is the enlargement of the dura and is common in connective tissue disorders, such as Marfan syndrome and Ehlers–Danlos syndrome. These conditions are sometimes found in conjunction with Arnold–Chiari malformation.
Spontaneous cerebrospinal fluid leak is the fluid and pressure loss of spinal fluid due to holes in the dura mater.
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