GENERAL HISTOLOGY

Detailed explanation-1: -The epidural space in the skull is a potential space, while it is actually present in the spinal cord. The subarachnoid space consists of the cerebrospinal fluid (CSF), major blood vessels, and cisterns .

Detailed explanation-2: -The space under the arachnoid, the subarachnoid space, is filled with cerebrospinal fluid and contains blood vessels. The pia mater is the innermost layer of meninges. This thin, delicate membrane is tightly bound to the surface of the brain and spinal cord and cannot be dissected away without damaging the surface.

Detailed explanation-3: -The spinal subarachnoid space is the space between the arachnoid mater and pia mater in the spine and is continuous with the intracranial subarachnoid space. It communicates with the intracranial subarachnoid space via the foramen magnum and ends at the level of the S2 vertebra.

Detailed explanation-4: -The classic view has been that a so-called subdural space is located between the arachnoid and dura and that subdural hematomas or hygromas are the result of blood or cerebrospinal fluid accumulating in this (preexisting) space.