Dura mater

Dura mater

Meninges of the CNS

The medulla spinalis and its membranes. The spinal cord is a long thin tubular bundle of Nerves that is an extension of the Central nervous system from the brain and is enclosed in and protected
Gray's	subject #193 872
MeSH	Dura+Mater

The dura mater (from the Latin "hard mother"), or pachymeninx, is the tough and inflexible outermost of the three layers of the meninges surrounding the brain and spinal cord. This is a list of the subjects in Gray's Anatomy: IX Neurology Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books The meninges (singular meninx) is the system of membranes which envelops the Central nervous system. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain The spinal cord is a long thin tubular bundle of Nerves that is an extension of the Central nervous system from the brain and is enclosed in and protected (The other two meningeal layers are the pia mater and the arachnoid mater. The pia mater (Latin "tender mother" itself a translation from Arabic) is the delicate innermost layer of the Meninges - the membranes surrounding the The arachnoid mater is one of the three Meninges, the membranes that cover the Brain and Spinal cord. ) The dura mater is not as tightly fitting around the spinal cord, extending past the spinal cord (at the second lumbar vertebra) to about the second sacral vertebra. A vertebra (plural vertebrae) is an individual Irregular bone in the spinal or Vertebral column ( aka ischis a flexuous and flexible column

1 Layers and reflections
2 Drainage
3 Clinical significance
4 References
5 Additional images
6 External links

Layers and reflections

The dura mater has two layers:

a superficial layer, which is actually the skull's inner periosteum

a deep layer, the dura mater proper. Periosteum is a Membrane that lines the outer surface of all bones, except at the joints of Long bones.

The dura separates into two layers at dural reflections, places where the inner dural layer is reflected as sheet-like protrusions into the cranial cavity. There are two main dural reflections:

The tentorium cerebelli exists between and separates the cerebellum and brainstem from the occipital lobes of the cerebrum. The tentorium cerebelli or cerebellar tentorium ( Latin: "tent of the Cerebellum " is an extension of the Dura mater that separates The cerebellum ( Latin: "little brain" is a region of the Brain that plays an important role in the integration of sensory perception The brain stem (or brainstem) is the lower part of the Brain, adjoining and structurally continuous with the Spinal cord. The occipital lobe is the visual processing center of the Mammalian Brain containing most of the anatomical region of the Visual cortex. The telencephalon (tɛlɛnˈsɛfəlɒn cerebrum, or forebrain is the most Anterior or especially in humans most Dorsal region of the ^[1]

The falx cerebri, which separates the two hemispheres of the brain, is located in the longitudinal cerebral fissure between the hemispheres. The falx cerebri, also known as the cerebral falx, so named from its sickle-like form is a strong arched fold of dura mater which descends vertically in the longitudinal fissure A cerebral hemisphere ( hemispherium cerebrale) is defined as one of the two regions of the Brain that are delineated by the body's median plane. The great longitudinal fissure (or longitudinal cerebral fissure, or longitudinal fissure, or interhemispheric fissure) is the deep groove which separates ^[2]

Drainage

The two layers of dura mater run together throughout most of the skull. Where they separate, the gap between them is called a dural venous sinus. The dural venous sinuses (also called dural sinuses, cerebral sinuses, or cranial sinuses) are venous channels found between layers of Dura These sinuses drain blood and cerebrospinal fluid from the brain and empty into the internal jugular vein. Cerebrospinal fluid ( CSF) Liquor cerebrospinalis, is a clear Bodily fluid that occupies the Subarachnoid space and the Ventricular system The internal jugular vein collects the blood from the Brain, the superficial parts of the Face, and the Neck.

They drain via the arachnoid villi, which are outgrowths of the arachnoid mater (the middle meningeal layer) that extend into the venous sinuses. Arachnoid granulations (or arachnoid villi) are small protrusions of the arachnoid (the thin second layer covering the brain through the Dura (the thick The arachnoid mater is one of the three Meninges, the membranes that cover the Brain and Spinal cord. These villi act as one-way valves.

Meningeal veins, which course through the dura mater, and bridging veins, which drain the underlying neural tissue and puncture the dura mater, empty into these dural sinuses.

Clinical significance

A subdural hematoma occurs when there is an abnormal collection of blood between the dura and the arachnoid, usually as a result of torn bridging veins secondary to head trauma. A subdural Hematoma (Subdural haematoma (SDH is a form of Traumatic brain injury in which Blood gathers between the dura (the outer protective An epidural hematoma is a collection of blood between the dura and the inner surface of the skull, and is usually due to arterial bleeding. Epidural or extradural hematoma is a type of Traumatic brain injury (TBI in which a buildup of blood occurs between the Dura mater (the tough outer Arteries are Blood vessels that carry blood away from the Heart.

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. Creutzfeldt-Jakob disease ( CJD) is a very rare and incurable degenerative neurological disorder ( Brain Disease) that is ultimately ^[3]

References

^ Shepherd S. 2004. "Head Trauma." Emedicine. com.
^ Vinas FC and Pilitsis J. 2004. "Penetrating Head Trauma." Emedicine. com.
^ Red Cross: http://www.redcross.org/services/biomed/0,1082,0_553_,00.html

Additional images

Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc.	Diagrammatic transverse section of the medulla spinalis and its membranes. The spinal cord is a long thin tubular bundle of Nerves that is an extension of the Central nervous system from the brain and is enclosed in and protected	Upper part of medulla spinalis and hind- and mid-brains; posterior aspect, exposed in situ.	Diagrammatic section of scalp.
Autopsy photo from the CDC: The white "sheet" being held by the forceps is the dura mater. An autopsy, also known as a post-mortem examination, necropsy, or obduction, is a Medical procedure that consists of a thorough Examination The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated Forceps are a handheld hinged instrument used for grasping and holding objects	Human brain dura mater