The ophthalmic artery enters the orbit through

Barriers formed by the dura mater are
a/
b/
c/
d/

The brain ventricles are:
a/
b/
c/

The following are dural sinuses:
a/
b/
c/

The membranes that surround the brain are:
a/
b/
c/

Cerebrospinal fluid is produced by

The spinal cord and the brain are invested by three meningeal layers:
a/
b/
c/

Dura mater is separated from arachnoid and pia mater by a tiny gap called

The space between the arachnoid and pia mater is filled with

The lateral sulcus transmits the artery