ventricleListen to pronunciation(VEN-trih-kul)A fluid-filled cavity in the heart or brain.Enlarge this image in new windowAnatomy of the brain, showing the cerebrum, cerebellum, brain stem, and other parts of the brain.Enlarge this image in new windowAnatomy of the inside of the brain, showing the pineal and pituitary glands, optic nerve, ventricles (with cerebrospinal fluid shown in blue), and other parts of the brain.Search NCI's Dictionary of Cancer TermsStarts withContainsBrowse:ABCDEFGHIJKLMNOPQRSTUVWXYZ#