Final answer:
Dural sinuses are lined by dura mater and are part of the venous structures that drain blood from the brain into the jugular veins. They include specialized infoldings of the dura mater and feature arachnoid villi that allow CSF to return to the blood.
Step-by-step explanation:
Dural sinuses are lined by dura mater, which is a thick fibrous layer, and they drain blood from the brain into the common venous return of the jugular veins. They are part of the brain's venous structures and are located within the dural mater, a protective covering of the central nervous system (CNS). The superior sagittal sinus is an example of a dural sinus that runs along the top of the longitudinal fissure and drains blood from the majority of the outer cerebrum. The dural sinuses include infoldings of the dura mater that fit into large crevasses of the brain. Among these infoldings are those that go through the midline separations of the cerebrum and cerebellum. One of these infoldings forms a shelf-like tent between the occipital lobes of the cerebrum and the cerebellum, while another surrounds the pituitary gland. A unique feature within the dural sinuses is the presence of arachnoid villi, which protrude into the sinuses to allow cerebrospinal fluid (CSF) to filter back into the blood for drainage.