Question #203
Considering the arachnoid mater, which of the following statements is true?
The arachnoid and pia mater are often considered together as the leptomeninges with the pia closely associated with brain matter and loosely connected to the overlying arachnoid with trabeculae. Between these two meninges in the area known as the subarachnoid space is the cerebrospinal fluid. It is here that the cerebral arteries lie and so arterial bleeds (usually from aneurysms arising from the Circle of Willis) will result in subarachnoid blood. The arachnoid itself is avascular.
It is the dura which forms the venous sinuses and falx cerebri.
