What does the choroid plexus primarily produce?

The choroid plexus is primarily responsible for producing cerebrospinal fluid (CSF), a clear fluid that surrounds and protects the brain and spinal cord. This structure is found in the ventricles of the brain, where it actively filters blood to create CSF. The production of cerebrospinal fluid is essential for maintaining the homeostasis of the central nervous system, as it provides cushioning for the brain, helps remove waste products, and plays a role in the distribution of nutrients.

Through specialized epithelial cells, the choroid plexus not only synthesizes CSF but also regulates its composition, ensuring that the brain remains in an optimal environment for function. This fluid is crucial for buoyancy, which reduces the weight of the brain inside the skull, thereby minimizing the chances of injury from impacts. Additionally, cerebrospinal fluid helps to maintain intracranial pressure and allows for the exchange of substances between the brain and the circulatory system.

The other options are not produced by the choroid plexus, as hormones are typically released from endocrine glands, neurotransmitters are synthesized by neurons, and blood cells are produced in the bone marrow. Thus, the primary and correct function of the choroid plexus is the production of cerebrosp