Which structure produces cerebrospinal fluid in the brain?

• A. Choroid plexus
• B. Amygdala
• C. Pineal gland
• D. Corpus callosum

Answer: (A)

The structure that produces cerebrospinal fluid is the choroid plexus, a capillary-rich network of ependymal cells lining the brain's ventricles. It filters blood and actively secretes a fluid filtrate to form CSF, primarily inside the lateral ventricles but also in the third and fourth ventricles. This fluid then circulates through the ventricular system and subarachnoid space, eventually being reabsorbed into the venous system. The amygdala handles emotions and memory, the pineal gland releases melatonin, and the corpus callosum connects the two brain hemispheres, none of which generate CSF.