Final answer:
The Subarachnoid space contains cerebrospinal fluid (CSF) and blood vessels, while nerve fibers and glands such as the choroid plexus are associated with it but not located within this space. The CSF in the subarachnoid space functions to remove metabolic wastes and provide a protective cushion for the CNS.
Step-by-step explanation:
The Subarachnoid space contains several crucial elements for the functioning and protection of the central nervous system (CNS). Among the constituents of this space are cerebrospinal fluid (CSF), blood vessels, and the trabeculae that form part of the arachnoid mater. Specifically, the CSF occupies the space between the arachnoid mater and the pia mater, and it contains water, small molecules, and electrolytes. This fluid is essential for collecting metabolic wastes from the nervous tissue and acting as a liquid cushion for both the brain and the spinal cord to provide mechanical and immunological protection.
Additionally, the subarachnoid space allows for the circulation of CSF, which picks up metabolic wastes and moves them out of the CNS. The arachnoid granulations help in reabsorbing the CSF into the blood for waste removal, achieving a critical clearing function. While nerve fibers and glands, such as the choroid plexus (that produce CSF), are nearby or associated with the production and circulation of CSF, they are not components of the subarachnoid space itself.