In the background of the smaller vessels, you can see quite large formations. For example, like going from the forehead to the back of the head.
These formations are called venous sinuses or sinuses of the dura mater. They can be called vascular "manifolds."
These pools (and so it is appropriate to call them from the anatomical point of view) collect blood from the internal and external veins of the brain. After that, the blood leaves the brain.
By the way, the sinus "from the forehead to the back of the head" that we gave as an example at the beginning of the post is called the sagittal sinus.