Brain: Structure and Function: blood vessels, meninges
In the skull there are some gaps, called foramina (Latin for "holes"). Here occur mainly blood vessels in the skull one or off. With the largest opening, the foramen magnum, the brain stem is connected to the spinal cord.
Inside the skull are the three meninges (Meninges) to:
The spaces between the meninges are with cerebrospinal fluid (CSF) filled.
The cerebrospinal fluid is formed in the cavities of the brain (ventricle) and on the one hand protects the brain from severe impacts on the other hand the brain disposed waste materials from the metabolism via the cerebrospinal fluid.
Important are the numerous small blood vessels of the brain: the capillaries. The cells lining the capillaries (endothelial cells), and the surrounding glial cells form a functional unit - it is called blood-brain barrier.
The blood-brain barrier allows only a few substances. Which substances to pass through the blood-brain barrier, control the endothelial and glial cells. In this way, the barrier prevents certain drugs, toxins, viruses and bacteria enter the brain.