Meninges Part1 Flashcards
How many layers in CNS?
Pia matter ( soft mother) thin ,closed, highly VASCULAR
Arachnoid matter (spider) connective tissue trabeculae, NON VASCULAR
Dura matter (tough strong) connective tissue, NON VASCULAR
What is dural venous sinuses?
The dura is divided into two layers
Inward - meningial layers
Outward -toward skull bone- periosteal layers
There is physiological spaces present between these layers covered with epithelial cells contain venous blood vessels to blood exchange. These spaces are called venous sinuses
There are also blood vessels know as meningial artery and vein run between these layers
Type of hemorrhages?
1- Extra dural or epidural hemorrhage:
Blood present between meningial and periosteal layer/ skull bone.( Potential space)
Causes? Trauma injury to skull (temporal)
Cause rupture of anterior branch of middle meningial artery or vein .
Lucid interval - progressively going into deeper level of unconscious later in life
Shape of hematoma in diagnosis: lens shape( biconvex)
Well localized,more pressure due to attachment of ligaments to sutures
2-Subdural hemorrhage:
Outside the arachnoid
Inside the dura
Skull+dura move together
Arachnoid+brain move together during injury cause damage to veins going through them
Causes - occur due to damage to bridging veins ( cerebral veins carrying blood from cerebral cortex to dural venous sinuses)
Due to deceleration injury (due to brain sudden shift of brain in skull
Commen in elders(brain gets small, float more, chances of shift because skull same size)
Unexplained, fluctuating level of consciousness
Crescent shaped
3- Sub arachnoid hemorrhage
Between arachnoid and pia
Due to presence of berry aneurysms ruptures in the circle of Willis
Arterio venous malformation ruptures
Sudden and severe headache
Raised intracranial pressure
Lumber puncture contain RBCS
4- Intra cerebral hemorrhage:
Due to hypertension
Small micro vessel rupture within the brain substance
