Ventricular system
Interconnected, fluid-filled spaces in the forebrain and brainstem derived from empty spaces in the embryonic neural tube. The lateral ventricles are present in the left and right hemispheres of the brain, which merges into the third ventricle at the interventricular foramen between the left and right thalamus. The third ventricle then connects with the cerebral aqueduct, which opens into the fourth ventricle between the pons and medulla. The fourth ventricle then connects with the spinal cord. The ventricles are filled with cerebrospinal fluid, produced by the choroid plexus located in the lateral, third, and fourth ventricles.
