Final answer:
Excess tissue fluid in the brain, or cerebrospinal fluid (CSF), is reabsorbed into the venous system via the dural sinuses, particularly the superior sagittal sinus, before draining into the jugular veins.
Step-by-step explanation:
Excess tissue fluid in the brain drains into the venous system. After cerebrospinal fluid (CSF) performs its function of cushioning the brain and spinal cord as well as removing metabolic wastes, it is reabsorbed through arachnoid granulations into the dural sinuses, particularly the superior sagittal sinus. From these sinuses, the blood, along with the CSF, moves towards the jugular veins for reoxygenation and circulation.In summary, these processes involve the cerebrospinal fluid (CSF) being produced by the choroid plexus, circulating through the CNS, picking up waste, and eventually being absorbed into the blood through the various sinuses. The superior sagittal sinus is one of the critical structures for this reabsorption, ensuring that the CSF and blood can drain from the brain through a series of sinuses that connect to the jugular veins.