THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The meninges are the layers of protective tissue that cover the brain and spinal cord.

Detailed explanation-2: -The middle layer of meninges is arachnoid, which resembles a cobweb in appearance, is a thin layer with numerous threadlike strands that attach it to the innermost layer. The space under the arachnoid, the subarachnoid space, is filled with cerebrospinal fluid and contains blood vessels.

Detailed explanation-3: -Arachnoid Mater The arachnoid sits between the dura and the pia and is an avascular membrane that is involved in cerebrospinal fluid (CSF) metabolism via the subarachnoid space. [2] Unlike the pia mater, the arachnoid does not follow the contours of the cortical sulci but bridges them.

Detailed explanation-4: -The arachnoid mater, named for its spiderweb-like appearance, is a thin, transparent membrane surrounding the spinal cord like a loosely fitting sac. Continuous with the cerebral arachnoid above, it passes through the foramen magnum and descends caudally to the S2 vertebral level.