FOURTH VENTRICLE
The fourth ventricle is a narrow cavity in the brain located in the hindbrain. It is a continuation of the central canal of the spinal cord and communicates with the cerebrospinal fluid (CSF) in the subarachnoid space.
Boundaries:
- Anteriorly: Pons
- Posteriorly: Cerebellum
- Inferiorly: Foramen magnum
- Superiorly: Dorsal edges of cerebellum
Features:
- Communicates with CSF in the subarachnoid space
- Contains choroid plexus
- Receives CSF from the aqueduct of Sylvius
Structures in the floor of the fourth ventricle:
- Trigone
- Facial colliculus
- Hypoglossal trigone
- Area postrema
- Medullary pyramids
Applied anatomy:
- CSF flows from the fourth ventricle to the subarachnoid space
- CSF is reabsorbed into the venous sinuses via the arachnoid villi
- The area postrema is sensitive to emetic stimuli and helps regulate vomiting