Glossary term:

Cerebral venous sinuses

Blood enters the brain through four arteries, one on each side of the midline at the front of the neck and another pair at the back of the neck. Having supplied oxygen and nutrients to the brain, the blood then flows into a system of draining veins, known as venous sinuses. The largest of these is the superior sagittal sinus, running along the top of the head, in the midline. Most (but not all) of this venous blood then flows out of the head into the internal jugular veins, there being one of these on each side of the midline.