19 of 10) What structure produces cerebrospinal fluid (CSF)? arachnoid mater O interventricular foramen O choroid plexus O central canal of the spinal cord cking any button other than the Save Answer
The Correct Answer and Explanation is:
The correct answer is: choroid plexus
Explanation
Cerebrospinal fluid (CSF) is a clear, colorless body fluid that surrounds the brain and spinal cord, providing mechanical and immunological protection to the central nervous system (CNS). It is primarily produced by the choroid plexus, a network of specialized ependymal cells and capillaries found within the ventricles of the brain.
There are four choroid plexuses—one in each of the lateral ventricles, one in the third ventricle, and one in the fourth ventricle. These structures filter blood plasma and secrete it as CSF into the ventricular system. The CSF then flows from the lateral ventricles through the interventricular foramen (foramen of Monro) into the third ventricle, and then through the cerebral aqueduct into the fourth ventricle. From the fourth ventricle, it enters the subarachnoid space around the brain and spinal cord.
The primary functions of CSF include:
- Cushioning the brain against trauma
- Providing nutrients and removing waste products
- Maintaining intracranial pressure
- Serving as a lymphatic substitute in the CNS
The other options are incorrect for the following reasons:
- Arachnoid mater: This is one of the three meninges (protective membranes), specifically the middle layer. While it plays a role in CSF circulation and reabsorption (via arachnoid granulations), it does not produce CSF.
- Interventricular foramen: These are passageways that connect the lateral ventricles to the third ventricle; they are not involved in CSF production.
- Central canal of the spinal cord: This is a small canal that allows CSF to flow through the spinal cord but does not produce it.
In conclusion, the choroid plexus is the specialized structure responsible for producing CSF, making it a critical component of the brain’s ventricular system and overall CNS homeostasis.
