The (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 . The other two meningeal layers are the
Pia Mater and the
Arachnoid Mater . The dura matter isn't as tightly fitting around the spinal cord, extending past the spinal cord (which ends at L2, or second lumbar vertebra) to about the S2 (second sacral vertebra).
The dura mater has two layers: a deep layer and a superficial layer that is actually the skull’s inner
Periosteum , the membrane that lines
Bone . 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 Lobe s of the
Cerebrum (Shepherd, 2004). The
Falx Cerebri , which separates the two
Hemispheres of the brain, is located in the
Longitudinal Cerebral Fissure between the hemispheres (Williams et al, 2002).
Channels called
Dural Venous Sinuses form between the two dural layers at dural reflections. These sinuses drain blood and cerebrospinal fluid from the brain and empty into the internal
Jugular Vein . 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.
A
Subdural Hematoma occurs when there is an abnormal collection of blood between the dura and the arachnoid, usually as a result of torn
Bridiging Vein s secondary to head trauma. 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.
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 .
# Shepherd S. 2004.
"Head Trauma." Emedicine.com.
# Vinas FC and Pilitsis J. 2004.
"Penetrating Head Trauma." Emedicine.com.
# Williams TH, Gluhbegovic N, Jew JY. 2002.
"The Human Brain: Chapter 2: The Meninges and Blood Vessels of the Brain" . University of Iowa.
# Red Cross: http://www.redcross.org/services/biomed/0,1082,0_553_,00.html
