Final answer:
The brain is protected by skull bones, vertebrae, protective meningeal layers, and cerebrospinal fluid (CSF) which cushions the CNS, circulates nutrients, removes waste, and helps maintain intracranial pressure.
Step-by-step explanation:
The brain is protected and supported by the bones of the skull and the vertebrae of the spine, along with the meninges, which are three layers of membrane. These membranes provide a tough physical barrier. Nested between two of these layers is the cerebrospinal fluid (CSF), which cushions the brain and spinal cord, circulates nutrients, removes waste products, and serves to protect the central nervous system (CNS) from trauma and infection.
CSF is produced by the choroid plexus in the ventricles of the brain. It flows throughout the CNS in the subarachnoid space between the arachnoid and pia mater layers of the meninges, and it is reabsorbed into the bloodstream. This circulation is crucial for maintaining intracranial pressure, facilitating blood perfusion, and preventing brain ischemia. However, if CSF production is excessive, or its flow is blocked, or if it is not adequately reabsorbed, this can lead to hydrocephalus, a condition characterized by the enlargement of ventricles and potential pressure on the brain.